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file_thp_enabled() incorrectly allows THP for files on anonymous inodes
(e.g. guest_memfd and secretmem). These files are created via
alloc_file_pseudo(), which does not call get_write_access() and leaves
inode->i_writecount at 0. Combined with S_ISREG(inode->i_mode) being
true, they appear as read-only regular files when
CONFIG_READ_ONLY_THP_FOR_FS is enabled, making them eligible for THP
collapse.
Anonymous inodes can never pass the inode_is_open_for_write() check
since their i_writecount is never incremented through the normal VFS
open path. The right thing to do is to exclude them from THP eligibility
altogether, since CONFIG_READ_ONLY_THP_FOR_FS was designed for real
filesystem files (e.g. shared libraries), not for pseudo-filesystem
inodes.
For guest_memfd, this allows khugepaged and MADV_COLLAPSE to create
large folios in the page cache via the collapse path, but the
guest_memfd fault handler does not support large folios. This triggers
WARN_ON_ONCE(folio_test_large(folio)) in kvm_gmem_fault_user_mapping().
For secretmem, collapse_file() tries to copy page contents through the
direct map, but secretmem pages are removed from the direct map. This
can result in a kernel crash:
BUG: unable to handle page fault for address: ffff88810284d000
RIP: 0010:memcpy_orig+0x16/0x130
Call Trace:
collapse_file
hpage_collapse_scan_file
madvise_collapse
Secretmem is not affected by the crash on upstream as the memory failure
recovery handles the failed copy gracefully, but it still triggers
confusing false memory failure reports:
Memory failure: 0x106d96f: recovery action for clean unevictable
LRU page: Recovered
Check IS_ANON_FILE(inode) in file_thp_enabled() to deny THP for all
anonymous inode files.
Link: https://syzkaller.appspot.com/bug?extid=33a04338019ac7e43a44
Link: https://lore.kernel.org/linux-mm/CAEvNRgHegcz3ro35ixkDw39ES8=U6rs6S7iP0gkR9enr7HoGtA@mail.gmail.com
Link: https://lkml.kernel.org/r/20260214001535.435626-1-kartikey406@gmail.com
Fixes: 7fbb5e188248 ("mm: remove VM_EXEC requirement for THP eligibility")
Signed-off-by: Deepanshu Kartikey <Kartikey406@gmail.com>
Reported-by: syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=33a04338019ac7e43a44
Tested-by: syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com
Tested-by: Lance Yang <lance.yang@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Tested-by: Ackerley Tng <ackerleytng@google.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Fangrui Song <i@maskray.me>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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KFENCE does not currently support KASAN hardware tags. As a result, the
two features are incompatible when enabled simultaneously.
Given that MTE provides deterministic protection and KFENCE is a
sampling-based debugging tool, prioritize the stronger hardware
protections. Disable KFENCE initialization and free the pre-allocated
pool if KASAN hardware tags are detected to ensure the system maintains
the security guarantees provided by MTE.
Link: https://lkml.kernel.org/r/20260213095410.1862978-1-glider@google.com
Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ernesto Martinez Garcia <ernesto.martinezgarcia@tugraz.at>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Kees Cook <kees@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Adapt tmpfs/shmem to use the rhashtable-based xattr path and switch
from an embedded struct to pointer-based lazy allocation.
Change shmem_inode_info.xattrs from embedded 'struct simple_xattrs' to
a pointer 'struct simple_xattrs *', initialized to NULL. This avoids
the rhashtable overhead for every tmpfs inode, which helps when a lot of
inodes exist.
The xattr store is allocated on first use:
- shmem_initxattrs(): Allocates via simple_xattrs_alloc() when
security modules set initial xattrs during inode creation.
- shmem_xattr_handler_set(): Allocates on first setxattr, with a
short-circuit for removal when no xattrs are stored yet.
All read paths (shmem_xattr_handler_get, shmem_listxattr) check for
NULL xattrs pointer and return -ENODATA or 0 respectively.
Replaced xattr entries are freed via simple_xattr_free_rcu() to allow
concurrent RCU readers to finish.
shmem_evict_inode() conditionally frees the xattr store only when
allocated.
Also change simple_xattr_add() from void to int to propagate
rhashtable insertion failures. shmem_initxattrs() is the only caller.
Link: https://patch.msgid.link/20260216-work-xattr-socket-v1-3-c2efa4f74cb7@kernel.org
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add rhashtable support to the simple_xattr subsystem while keeping the
existing rbtree code fully functional. This allows consumers to be
migrated one at a time without breaking any intermediate build.
struct simple_xattrs gains a dispatch flag and a union holding either
the rbtree (rb_root + rwlock) or rhashtable state:
struct simple_xattrs {
bool use_rhashtable;
union {
struct { struct rb_root rb_root; rwlock_t lock; };
struct rhashtable ht;
};
};
simple_xattrs_init() continues to set up the rbtree path for existing
embedded-struct callers.
Add simple_xattrs_alloc() which dynamically allocates a simple_xattrs
and initializes the rhashtable path. This is the entry point for
consumers switching to pointer-based lazy allocation.
The five core functions (get, set, list, add, free) dispatch based on
the use_rhashtable flag.
Existing callers continue to use the rbtree path unchanged. As each
consumer is converted it will switch to simple_xattrs_alloc() and the
rhashtable path. Once all consumers are converted a follow-up patch
will remove the rbtree code.
Link: https://patch.msgid.link/20260216-work-xattr-socket-v1-2-c2efa4f74cb7@kernel.org
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Conversion performed via this Coccinelle script:
// SPDX-License-Identifier: GPL-2.0-only
// Options: --include-headers-for-types --all-includes --include-headers --keep-comments
virtual patch
@gfp depends on patch && !(file in "tools") && !(file in "samples")@
identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
kzalloc_obj,kzalloc_objs,kzalloc_flex,
kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
@@
ALLOC(...
- , GFP_KERNEL
)
$ make coccicheck MODE=patch COCCI=gfp.cocci
Build and boot tested x86_64 with Fedora 42's GCC and Clang:
Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.
As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull kmalloc_obj conversion from Kees Cook:
"This does the tree-wide conversion to kmalloc_obj() and friends using
coccinelle, with a subsequent small manual cleanup of whitespace
alignment that coccinelle does not handle.
This uncovered a clang bug in __builtin_counted_by_ref(), so the
conversion is preceded by disabling that for current versions of
clang. The imminent clang 22.1 release has the fix.
I've done allmodconfig build tests for x86_64, arm64, i386, and arm. I
did defconfig builds for alpha, m68k, mips, parisc, powerpc, riscv,
s390, sparc, sh, arc, csky, xtensa, hexagon, and openrisc"
* tag 'kmalloc_obj-treewide-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kmalloc_obj: Clean up after treewide replacements
treewide: Replace kmalloc with kmalloc_obj for non-scalar types
compiler_types: Disable __builtin_counted_by_ref for Clang
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git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock fix from Mike Rapoport:
"Fix detection of NUMA node for CXL windows
phys_to_target_node() may assign a CXL Fixed Memory Window to the
wrong NUMA node when a CXL node resides in the gap of discontinuous
System RAM node.
Fix this by checking both numa_meminfo and numa_reserved_meminfo,
preferring the reserved NID when the address appears in both"
* tag 'fixes-2026-02-21' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
mm: numa_memblks: Identify the accurate NUMA ID of CFMW
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This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a
couple of issues in the demotion code - pages were failed demotion
and were finding themselves demoted into disallowed nodes (Bing Jiao)
- "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare
mapledtree race and performs a number of cleanups (Liam Howlett)
- "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use
them" implements a lot of cleanups following on from the conversion
of the VMA flags into a bitmap (Lorenzo Stoakes)
- "support batch checking of references and unmapping for large folios"
implements batching to greatly improve the performance of reclaiming
clean file-backed large folios (Baolin Wang)
- "selftests/mm: add memory failure selftests" does as claimed (Miaohe
Lin)
* tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits)
mm/page_alloc: clear page->private in free_pages_prepare()
selftests/mm: add memory failure dirty pagecache test
selftests/mm: add memory failure clean pagecache test
selftests/mm: add memory failure anonymous page test
mm: rmap: support batched unmapping for file large folios
arm64: mm: implement the architecture-specific clear_flush_young_ptes()
arm64: mm: support batch clearing of the young flag for large folios
arm64: mm: factor out the address and ptep alignment into a new helper
mm: rmap: support batched checks of the references for large folios
tools/testing/vma: add VMA userland tests for VMA flag functions
tools/testing/vma: separate out vma_internal.h into logical headers
tools/testing/vma: separate VMA userland tests into separate files
mm: make vm_area_desc utilise vma_flags_t only
mm: update all remaining mmap_prepare users to use vma_flags_t
mm: update shmem_[kernel]_file_*() functions to use vma_flags_t
mm: update secretmem to use VMA flags on mmap_prepare
mm: update hugetlbfs to use VMA flags on mmap_prepare
mm: add basic VMA flag operation helper functions
tools: bitmap: add missing bitmap_[subset(), andnot()]
mm: add mk_vma_flags() bitmap flag macro helper
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull more slab updates from Vlastimil Babka:
- Two stable fixes for kmalloc_nolock() usage from NMI context (Harry
Yoo)
- Allow kmalloc_nolock() allocations to be freed with kfree() and thus
also kfree_rcu() and simplify slabobj_ext handling - we no longer
need to track how it was allocated to use the matching freeing
function (Harry Yoo)
* tag 'slab-for-7.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm/slab: drop the OBJEXTS_NOSPIN_ALLOC flag from enum objext_flags
mm/slab: allow freeing kmalloc_nolock()'d objects using kfree[_rcu]()
mm/slab: use prandom if !allow_spin
mm/slab: do not access current->mems_allowed_seq if !allow_spin
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git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock updates from Mike Rapoport:
- update tools/include/linux/mm.h to fix memblock tests compilation
- drop redundant struct page* parameter from memblock_free_pages() and
get struct page from the pfn
- add underflow detection for size calculation in memtest and warn
about underflow when VM_DEBUG is enabled
* tag 'memblock-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
mm/memtest: add underflow detection for size calculation
memblock: drop redundant 'struct page *' argument from memblock_free_pages()
memblock test: include <linux/sizes.h> from tools mm.h stub
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In some physical memory layout designs, the address space of CFMW (CXL
Fixed Memory Window) resides between multiple segments of system memory
belonging to the same NUMA node. In numa_cleanup_meminfo, these multiple
segments of system memory are merged into a larger numa_memblk. When
identifying which NUMA node the CFMW belongs to, it may be incorrectly
assigned to the NUMA node of the merged system memory.
When a CXL RAM region is created in userspace, the memory capacity of
the newly created region is not added to the CFMW-dedicated NUMA node.
Instead, it is accumulated into an existing NUMA node (e.g., NUMA0
containing RAM). This makes it impossible to clearly distinguish
between the two types of memory, which may affect memory-tiering
applications.
Example memory layout:
Physical address space:
0x00000000 - 0x1FFFFFFF System RAM (node0)
0x20000000 - 0x2FFFFFFF CXL CFMW (node2)
0x40000000 - 0x5FFFFFFF System RAM (node0)
0x60000000 - 0x7FFFFFFF System RAM (node1)
After numa_cleanup_meminfo, the two node0 segments are merged into one:
0x00000000 - 0x5FFFFFFF System RAM (node0) // CFMW is inside the range
0x60000000 - 0x7FFFFFFF System RAM (node1)
So the CFMW (0x20000000-0x2FFFFFFF) will be incorrectly assigned to node0.
To address this scenario, accurately identifying the correct NUMA node
can be achieved by checking whether the region belongs to both
numa_meminfo and numa_reserved_meminfo.
While this issue is only observed in a QEMU configuration, and no known
end users are impacted by this problem, it is likely that some firmware
implementation is leaving memory map holes in a CXL Fixed Memory Window.
CXL hotplug depends on mapping free window capacity, and it seems to be
only a coincidence to have not hit this problem yet.
Fixes: 779dd20cfb56 ("cxl/region: Add region creation support")
Signed-off-by: Cui Chao <cuichao1753@phytium.com.cn>
Cc: stable@vger.kernel.org
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20260213060347.2389818-2-cuichao1753@phytium.com.cn
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM fixes from Andrew Morton:
"Three MM hotfixes, all three are cc:stable"
* tag 'mm-hotfixes-stable-2026-02-13-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
procfs: fix possible double mmput() in do_procmap_query()
mm/page_alloc: skip debug_check_no_{obj,locks}_freed with FPI_TRYLOCK
mm/hugetlb: restore failed global reservations to subpool
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Pull KVM updates from Paolo Bonzini:
"Loongarch:
- Add more CPUCFG mask bits
- Improve feature detection
- Add lazy load support for FPU and binary translation (LBT) register
state
- Fix return value for memory reads from and writes to in-kernel
devices
- Add support for detecting preemption from within a guest
- Add KVM steal time test case to tools/selftests
ARM:
- Add support for FEAT_IDST, allowing ID registers that are not
implemented to be reported as a normal trap rather than as an UNDEF
exception
- Add sanitisation of the VTCR_EL2 register, fixing a number of
UXN/PXN/XN bugs in the process
- Full handling of RESx bits, instead of only RES0, and resulting in
SCTLR_EL2 being added to the list of sanitised registers
- More pKVM fixes for features that are not supposed to be exposed to
guests
- Make sure that MTE being disabled on the pKVM host doesn't give it
the ability to attack the hypervisor
- Allow pKVM's host stage-2 mappings to use the Force Write Back
version of the memory attributes by using the "pass-through'
encoding
- Fix trapping of ICC_DIR_EL1 on GICv5 hosts emulating GICv3 for the
guest
- Preliminary work for guest GICv5 support
- A bunch of debugfs fixes, removing pointless custom iterators
stored in guest data structures
- A small set of FPSIMD cleanups
- Selftest fixes addressing the incorrect alignment of page
allocation
- Other assorted low-impact fixes and spelling fixes
RISC-V:
- Fixes for issues discoverd by KVM API fuzzing in
kvm_riscv_aia_imsic_has_attr(), kvm_riscv_aia_imsic_rw_attr(), and
kvm_riscv_vcpu_aia_imsic_update()
- Allow Zalasr, Zilsd and Zclsd extensions for Guest/VM
- Transparent huge page support for hypervisor page tables
- Adjust the number of available guest irq files based on MMIO
register sizes found in the device tree or the ACPI tables
- Add RISC-V specific paging modes to KVM selftests
- Detect paging mode at runtime for selftests
s390:
- Performance improvement for vSIE (aka nested virtualization)
- Completely new memory management. s390 was a special snowflake that
enlisted help from the architecture's page table management to
build hypervisor page tables, in particular enabling sharing the
last level of page tables. This however was a lot of code (~3K
lines) in order to support KVM, and also blocked several features.
The biggest advantages is that the page size of userspace is
completely independent of the page size used by the guest:
userspace can mix normal pages, THPs and hugetlbfs as it sees fit,
and in fact transparent hugepages were not possible before. It's
also now possible to have nested guests and guests with huge pages
running on the same host
- Maintainership change for s390 vfio-pci
- Small quality of life improvement for protected guests
x86:
- Add support for giving the guest full ownership of PMU hardware
(contexted switched around the fastpath run loop) and allowing
direct access to data MSRs and PMCs (restricted by the vPMU model).
KVM still intercepts access to control registers, e.g. to enforce
event filtering and to prevent the guest from profiling sensitive
host state. This is more accurate, since it has no risk of
contention and thus dropped events, and also has significantly less
overhead.
For more information, see the commit message for merge commit
bf2c3138ae36 ("Merge tag 'kvm-x86-pmu-6.20' ...")
- Disallow changing the virtual CPU model if L2 is active, for all
the same reasons KVM disallows change the model after the first
KVM_RUN
- Fix a bug where KVM would incorrectly reject host accesses to PV
MSRs when running with KVM_CAP_ENFORCE_PV_FEATURE_CPUID enabled,
even if those were advertised as supported to userspace,
- Fix a bug with protected guest state (SEV-ES/SNP and TDX) VMs,
where KVM would attempt to read CR3 configuring an async #PF entry
- Fail the build if EXPORT_SYMBOL_GPL or EXPORT_SYMBOL is used in KVM
(for x86 only) to enforce usage of EXPORT_SYMBOL_FOR_KVM_INTERNAL.
Only a few exports that are intended for external usage, and those
are allowed explicitly
- When checking nested events after a vCPU is unblocked, ignore
-EBUSY instead of WARNing. Userspace can sometimes put the vCPU
into what should be an impossible state, and spurious exit to
userspace on -EBUSY does not really do anything to solve the issue
- Also throw in the towel and drop the WARN on INIT/SIPI being
blocked when vCPU is in Wait-For-SIPI, which also resulted in
playing whack-a-mole with syzkaller stuffing architecturally
impossible states into KVM
- Add support for new Intel instructions that don't require anything
beyond enumerating feature flags to userspace
- Grab SRCU when reading PDPTRs in KVM_GET_SREGS2
- Add WARNs to guard against modifying KVM's CPU caps outside of the
intended setup flow, as nested VMX in particular is sensitive to
unexpected changes in KVM's golden configuration
- Add a quirk to allow userspace to opt-in to actually suppress EOI
broadcasts when the suppression feature is enabled by the guest
(currently limited to split IRQCHIP, i.e. userspace I/O APIC).
Sadly, simply fixing KVM to honor Suppress EOI Broadcasts isn't an
option as some userspaces have come to rely on KVM's buggy behavior
(KVM advertises Supress EOI Broadcast irrespective of whether or
not userspace I/O APIC supports Directed EOIs)
- Clean up KVM's handling of marking mapped vCPU pages dirty
- Drop a pile of *ancient* sanity checks hidden behind in KVM's
unused ASSERT() macro, most of which could be trivially triggered
by the guest and/or user, and all of which were useless
- Fold "struct dest_map" into its sole user, "struct rtc_status", to
make it more obvious what the weird parameter is used for, and to
allow fropping these RTC shenanigans if CONFIG_KVM_IOAPIC=n
- Bury all of ioapic.h, i8254.h and related ioctls (including
KVM_CREATE_IRQCHIP) behind CONFIG_KVM_IOAPIC=y
- Add a regression test for recent APICv update fixes
- Handle "hardware APIC ISR", a.k.a. SVI, updates in
kvm_apic_update_apicv() to consolidate the updates, and to
co-locate SVI updates with the updates for KVM's own cache of ISR
information
- Drop a dead function declaration
- Minor cleanups
x86 (Intel):
- Rework KVM's handling of VMCS updates while L2 is active to
temporarily switch to vmcs01 instead of deferring the update until
the next nested VM-Exit.
The deferred updates approach directly contributed to several bugs,
was proving to be a maintenance burden due to the difficulty in
auditing the correctness of deferred updates, and was polluting
"struct nested_vmx" with a growing pile of booleans
- Fix an SGX bug where KVM would incorrectly try to handle EPCM page
faults, and instead always reflect them into the guest. Since KVM
doesn't shadow EPCM entries, EPCM violations cannot be due to KVM
interference and can't be resolved by KVM
- Fix a bug where KVM would register its posted interrupt wakeup
handler even if loading kvm-intel.ko ultimately failed
- Disallow access to vmcb12 fields that aren't fully supported,
mostly to avoid weirdness and complexity for FRED and other
features, where KVM wants enable VMCS shadowing for fields that
conditionally exist
- Print out the "bad" offsets and values if kvm-intel.ko refuses to
load (or refuses to online a CPU) due to a VMCS config mismatch
x86 (AMD):
- Drop a user-triggerable WARN on nested_svm_load_cr3() failure
- Add support for virtualizing ERAPS. Note, correct virtualization of
ERAPS relies on an upcoming, publicly announced change in the APM
to reduce the set of conditions where hardware (i.e. KVM) *must*
flush the RAP
- Ignore nSVM intercepts for instructions that are not supported
according to L1's virtual CPU model
- Add support for expedited writes to the fast MMIO bus, a la VMX's
fastpath for EPT Misconfig
- Don't set GIF when clearing EFER.SVME, as GIF exists independently
of SVM, and allow userspace to restore nested state with GIF=0
- Treat exit_code as an unsigned 64-bit value through all of KVM
- Add support for fetching SNP certificates from userspace
- Fix a bug where KVM would use vmcb02 instead of vmcb01 when
emulating VMLOAD or VMSAVE on behalf of L2
- Misc fixes and cleanups
x86 selftests:
- Add a regression test for TPR<=>CR8 synchronization and IRQ masking
- Overhaul selftest's MMU infrastructure to genericize stage-2 MMU
support, and extend x86's infrastructure to support EPT and NPT
(for L2 guests)
- Extend several nested VMX tests to also cover nested SVM
- Add a selftest for nested VMLOAD/VMSAVE
- Rework the nested dirty log test, originally added as a regression
test for PML where KVM logged L2 GPAs instead of L1 GPAs, to
improve test coverage and to hopefully make the test easier to
understand and maintain
guest_memfd:
- Remove kvm_gmem_populate()'s preparation tracking and half-baked
hugepage handling. SEV/SNP was the only user of the tracking and it
can do it via the RMP
- Retroactively document and enforce (for SNP) that
KVM_SEV_SNP_LAUNCH_UPDATE and KVM_TDX_INIT_MEM_REGION require the
source page to be 4KiB aligned, to avoid non-trivial complexity for
something that no known VMM seems to be doing and to avoid an API
special case for in-place conversion, which simply can't support
unaligned sources
- When populating guest_memfd memory, GUP the source page in common
code and pass the refcounted page to the vendor callback, instead
of letting vendor code do the heavy lifting. Doing so avoids a
looming deadlock bug with in-place due an AB-BA conflict betwee
mmap_lock and guest_memfd's filemap invalidate lock
Generic:
- Fix a bug where KVM would ignore the vCPU's selected address space
when creating a vCPU-specific mapping of guest memory. Actually
this bug could not be hit even on x86, the only architecture with
multiple address spaces, but it's a bug nevertheless"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (267 commits)
KVM: s390: Increase permitted SE header size to 1 MiB
MAINTAINERS: Replace backup for s390 vfio-pci
KVM: s390: vsie: Fix race in acquire_gmap_shadow()
KVM: s390: vsie: Fix race in walk_guest_tables()
KVM: s390: Use guest address to mark guest page dirty
irqchip/riscv-imsic: Adjust the number of available guest irq files
RISC-V: KVM: Transparent huge page support
RISC-V: KVM: selftests: Add Zalasr extensions to get-reg-list test
RISC-V: KVM: Allow Zalasr extensions for Guest/VM
KVM: riscv: selftests: Add riscv vm satp modes
KVM: riscv: selftests: add Zilsd and Zclsd extension to get-reg-list test
riscv: KVM: allow Zilsd and Zclsd extensions for Guest/VM
RISC-V: KVM: Skip IMSIC update if vCPU IMSIC state is not initialized
RISC-V: KVM: Fix null pointer dereference in kvm_riscv_aia_imsic_rw_attr()
RISC-V: KVM: Fix null pointer dereference in kvm_riscv_aia_imsic_has_attr()
RISC-V: KVM: Remove unnecessary 'ret' assignment
KVM: s390: Add explicit padding to struct kvm_s390_keyop
KVM: LoongArch: selftests: Add steal time test case
LoongArch: KVM: Add paravirt vcpu_is_preempted() support in guest side
LoongArch: KVM: Add paravirt preempt feature in hypervisor side
...
|
|
Several subsystems (slub, shmem, ttm, etc.) use page->private but don't
clear it before freeing pages. When these pages are later allocated as
high-order pages and split via split_page(), tail pages retain stale
page->private values.
This causes a use-after-free in the swap subsystem. The swap code uses
page->private to track swap count continuations, assuming freshly
allocated pages have page->private == 0. When stale values are present,
swap_count_continued() incorrectly assumes the continuation list is valid
and iterates over uninitialized page->lru containing LIST_POISON values,
causing a crash:
KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]
RIP: 0010:__do_sys_swapoff+0x1151/0x1860
Fix this by clearing page->private in free_pages_prepare(), ensuring all
freed pages have clean state regardless of previous use.
Link: https://lkml.kernel.org/r/20260207173615.146159-1-mikhail.v.gavrilov@gmail.com
Fixes: 3b8000ae185c ("mm/vmalloc: huge vmalloc backing pages should be split rather than compound")
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Suggested-by: Zi Yan <ziy@nvidia.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Similar to folio_referenced_one(), we can apply batched unmapping for file
large folios to optimize the performance of file folios reclamation.
Barry previously implemented batched unmapping for lazyfree anonymous
large folios[1] and did not further optimize anonymous large folios or
file-backed large folios at that stage. As for file-backed large folios,
the batched unmapping support is relatively straightforward, as we only
need to clear the consecutive (present) PTE entries for file-backed large
folios.
Note that it's not ready to support batched unmapping for uffd case, so
let's still fallback to per-page unmapping for the uffd case.
Performance testing:
Allocate 10G clean file-backed folios by mmap() in a memory cgroup, and
try to reclaim 8G file-backed folios via the memory.reclaim interface. I
can observe 75% performance improvement on my Arm64 32-core server (and
50%+ improvement on my X86 machine) with this patch.
W/o patch:
real 0m1.018s
user 0m0.000s
sys 0m1.018s
W/ patch:
real 0m0.249s
user 0m0.000s
sys 0m0.249s
[1] https://lore.kernel.org/all/20250214093015.51024-4-21cnbao@gmail.com/T/#u
Link: https://lkml.kernel.org/r/b53a16f67c93a3fe65e78092069ad135edf00eff.1770645603.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Barry Song <baohua@kernel.org>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "support batch checking of references and unmapping for large
folios", v6.
Currently, folio_referenced_one() always checks the young flag for each
PTE sequentially, which is inefficient for large folios. This
inefficiency is especially noticeable when reclaiming clean file-backed
large folios, where folio_referenced() is observed as a significant
performance hotspot.
Moreover, on Arm architecture, which supports contiguous PTEs, there is
already an optimization to clear the young flags for PTEs within a
contiguous range. However, this is not sufficient. We can extend this to
perform batched operations for the entire large folio (which might exceed
the contiguous range: CONT_PTE_SIZE).
Similar to folio_referenced_one(), we can also apply batched unmapping for
large file folios to optimize the performance of file folio reclamation.
By supporting batched checking of the young flags, flushing TLB entries,
and unmapping, I can observed a significant performance improvements in my
performance tests for file folios reclamation. Please check the
performance data in the commit message of each patch.
This patch (of 5):
Currently, folio_referenced_one() always checks the young flag for each
PTE sequentially, which is inefficient for large folios. This
inefficiency is especially noticeable when reclaiming clean file-backed
large folios, where folio_referenced() is observed as a significant
performance hotspot.
Moreover, on Arm64 architecture, which supports contiguous PTEs, there is
already an optimization to clear the young flags for PTEs within a
contiguous range. However, this is not sufficient. We can extend this to
perform batched operations for the entire large folio (which might exceed
the contiguous range: CONT_PTE_SIZE).
Introduce a new API: clear_flush_young_ptes() to facilitate batched
checking of the young flags and flushing TLB entries, thereby improving
performance during large folio reclamation. And it will be overridden by
the architecture that implements a more efficient batch operation in the
following patches.
While we are at it, rename ptep_clear_flush_young_notify() to
clear_flush_young_ptes_notify() to indicate that this is a batch
operation.
Link: https://lkml.kernel.org/r/cover.1770645603.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/12132694536834262062d1fb304f8f8a064b6750.1770645603.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Now we have eliminated all uses of vm_area_desc->vm_flags, eliminate this
field, and have mmap_prepare users utilise the vma_flags_t
vm_area_desc->vma_flags field only.
As part of this change we alter is_shared_maywrite() to accept a
vma_flags_t parameter, and introduce is_shared_maywrite_vm_flags() for use
with legacy vm_flags_t flags.
We also update struct mmap_state to add a union between vma_flags and
vm_flags temporarily until the mmap logic is also converted to using
vma_flags_t.
Also update the VMA userland tests to reflect this change.
Link: https://lkml.kernel.org/r/fd2a2938b246b4505321954062b1caba7acfc77a.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Yury Norov <ynorov@nvidia.com>
Cc: Chris Mason <clm@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
We will be shortly removing the vm_flags_t field from vm_area_desc so we
need to update all mmap_prepare users to only use the dessc->vma_flags
field.
This patch achieves that and makes all ancillary changes required to make
this possible.
This lays the groundwork for future work to eliminate the use of
vm_flags_t in vm_area_desc altogether and more broadly throughout the
kernel.
While we're here, we take the opportunity to replace VM_REMAP_FLAGS with
VMA_REMAP_FLAGS, the vma_flags_t equivalent.
No functional changes intended.
Link: https://lkml.kernel.org/r/fb1f55323799f09fe6a36865b31550c9ec67c225.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Damien Le Moal <dlemoal@kernel.org> [zonefs]
Acked-by: "Darrick J. Wong" <djwong@kernel.org>
Acked-by: Pedro Falcato <pfalcato@suse.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Yury Norov <ynorov@nvidia.com>
Cc: Chris Mason <clm@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In order to be able to use only vma_flags_t in vm_area_desc we must adjust
shmem file setup functions to operate in terms of vma_flags_t rather than
vm_flags_t.
This patch makes this change and updates all callers to use the new
functions.
No functional changes intended.
[akpm@linux-foundation.org: comment fixes, per Baolin]
Link: https://lkml.kernel.org/r/736febd280eb484d79cef5cf55b8a6f79ad832d2.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Yury Norov <ynorov@nvidia.com>
Cc: Chris Mason <clm@fb.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This patch updates secretmem to use the new vma_flags_t type which will
soon supersede vm_flags_t altogether.
In order to make this change we also have to update mlock_future_ok(), we
replace the vm_flags_t parameter with a simple boolean is_vma_locked one,
which also simplifies the invocation here.
This is laying the groundwork for eliminating the vm_flags_t in
vm_area_desc and more broadly throughout the kernel.
No functional changes intended.
[lorenzo.stoakes@oracle.com: fix check_brk_limits(), per Chris]
Link: https://lkml.kernel.org/r/3aab9ab1-74b4-405e-9efb-08fc2500c06e@lucifer.local
Link: https://lkml.kernel.org/r/a243a09b0a5d0581e963d696de1735f61f5b2075.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Yury Norov <ynorov@nvidia.com>
Cc: Chris Mason <clm@fb.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In order to update all mmap_prepare users to utilising the new VMA flags
type vma_flags_t and associated helper functions, we start by updating
hugetlbfs which has a lot of additional logic that requires updating to
make this change.
This is laying the groundwork for eliminating the vm_flags_t from struct
vm_area_desc and using vma_flags_t only, which further lays the ground for
removing the deprecated vm_flags_t type altogether.
No functional changes intended.
Link: https://lkml.kernel.org/r/9226bec80c9aa3447cc2b83354f733841dba8a50.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Yury Norov <ynorov@nvidia.com>
Cc: Chris Mason <clm@fb.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In order to stay consistent between functions which manipulate a
vm_flags_t argument of the form of vma_flags_...() and those which
manipulate a VMA (in this case the flags field of a VMA), rename
vma_flag_[test/set]_atomic() to vma_[test/set]_atomic_flag().
This lays the groundwork for adding VMA flag manipulation functions in a
subsequent commit.
Link: https://lkml.kernel.org/r/033dcf12e819dee5064582bced9b12ea346d1607.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Yury Norov <ynorov@nvidia.com>
Cc: Chris Mason <clm@fb.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Pass through the unmap_desc to free_pgtables() because it almost has
everything necessary and is already on the stack.
Updates testing code as necessary.
No functional changes intended.
[Liam.Howlett@oracle.com: fix up unmap desc use on exit_mmap()]
Link: https://lkml.kernel.org/r/20260210214214.364856-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20260121164946.2093480-12-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
There is no need to open code the vms_clear_ptes() now that unmap_desc
struct is used.
Link: https://lkml.kernel.org/r/20260121164946.2093480-11-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Convert vms_clear_ptes() to use unmap_desc to call unmap_vmas() instead of
the large argument list. The UNMAP_STATE() cannot be used because the vma
iterator in the vms does not point to the correct maple state
(mas_detach), and the tree_end will be set incorrectly. Setting up the
arguments manually avoids setting the struct up incorrectly and doing
extra work to get the correct pagetable range.
exit_mmap() also calls unmap_vmas() with many arguments. Using the
unmap_all_init() function to set the unmap descriptor for all vmas makes
this a bit easier to read.
Update to the vma test code is necessary to ensure testing continues to
function.
No functional changes intended.
Link: https://lkml.kernel.org/r/20260121164946.2093480-10-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The unmap_region code uses a number of arguments that could use better
documentation. With the addition of a descriptor for unmap (called
unmap_desc), the arguments can be more self-documenting and increase the
descriptions within the declaration.
No functional change intended
Link: https://lkml.kernel.org/r/20260121164946.2093480-9-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When the dup_mmap() fails during the vma duplication or setup, don't write
the XA_ZERO entry in the vma tree. Instead, destroy the tree and free the
new resources, leaving an empty vma tree.
Using XA_ZERO introduced races where the vma could be found between
dup_mmap() dropping all locks and exit_mmap() taking the locks. The race
can occur because the mm can be reached through the other trees via
successfully copied vmas and other methods such as the swapoff code.
XA_ZERO was marking the location to stop vma removal and pagetable
freeing. The newly created arguments to the unmap_vmas() and
free_pgtables() serve this function.
Replacing the XA_ZERO entry use with the new argument list also means the
checks for xa_is_zero() are no longer necessary so these are also removed.
Note that dup_mmap() now cleans up when ALL vmas are successfully copied,
but the dup_mmap() fails to completely set up some other aspect of the
duplication.
Link: https://lkml.kernel.org/r/20260121164946.2093480-8-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The unmap_region() calls need to pass through the page table limit for a
future patch.
No functional changes intended.
Link: https://lkml.kernel.org/r/20260121164946.2093480-7-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The ceiling and tree search limit need to be different arguments for the
future change in the failed fork attempt. The ceiling and floor variables
are not very descriptive, so change them to pg_start/pg_end.
Adding a new variable for the vma_end to the function as it will differ
from the pg_end in the later patches in the series.
Add a kernel doc about the free_pgtables() function.
Test code also updated.
No functional changes intended.
Link: https://lkml.kernel.org/r/20260121164946.2093480-6-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Add a limit to the vma search instead of using the start and end of the
one passed in.
No functional changes intended.
Link: https://lkml.kernel.org/r/20260121164946.2093480-5-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Create the new function tear_down_vmas() to remove a range of vmas.
exit_mmap() will be removing all the vmas.
This is necessary for future patches.
No functional changes intended.
Link: https://lkml.kernel.org/r/20260121164946.2093480-4-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Move the trace point later in the function so that it is not skipped in
the event of a failed fork.
Link: https://lkml.kernel.org/r/20260121164946.2093480-3-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Acked-by: Chris Li <chrisl@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series " Remove XA_ZERO from error recovery of dup_mmap()", v3.
It is possible that the dup_mmap() call fails on allocating or setting up
a vma after the maple tree of the oldmm is copied. Today, that failure
point is marked by inserting an XA_ZERO entry over the failure point so
that the exact location does not need to be communicated through to
exit_mmap().
However, a race exists in the tear down process because the dup_mmap()
drops the mmap lock before exit_mmap() can remove the partially set up vma
tree. This means that other tasks may get to the mm tree and find the
invalid vma pointer (since it's an XA_ZERO entry), even though the mm is
marked as MMF_OOM_SKIP and MMF_UNSTABLE.
To remove the race fully, the tree must be cleaned up before dropping the
lock. This is accomplished by extracting the vma cleanup in exit_mmap()
and changing the required functions to pass through the vma search limit.
Any other tree modifications would require extra cycles which should be
spent on freeing memory.
This does run the risk of increasing the possibility of finding no vmas
(which is already possible!) in code that isn't careful.
The final four patches are to address the excessive argument lists being
passed between the functions. Using the struct unmap_desc also allows
some special-case code to be removed in favour of the struct setup
differences.
This patch (of 11):
pgtables.h defines a fallback for ceiling and floor of the page tables
within the CONFIG_MMU section. Moving the definitions to outside the
CONFIG_MMU allows for using them in generic code.
[akpm@linux-foundation.org: remove stray newline, per SeongJae]
Link: https://lkml.kernel.org/r/20260121164946.2093480-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20260121164946.2093480-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: SeongJae Park <sj@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
riscv64-gcc-linux-gnu (v8.5) reports a compile time assert in:
r[2] = DEFINE_RANGE(clamp_t(s64, fault_idx - radius, pg.start, pg.end),
clamp_t(s64, fault_idx + radius, pg.start, pg.end));
where it decides that pg.start > pg.end in:
clamp_t(s64, fault_idx + radius, pg.start, pg.end));
where pg comes from:
const struct range pg = DEFINE_RANGE(0, folio_nr_pages(folio) - 1);
That does not seem like it could be true. Even for pg.start == pg.end,
we would need folio_test_large() to evaluate to false at compile time:
static inline unsigned long folio_nr_pages(const struct folio *folio)
{
if (!folio_test_large(folio))
return 1;
return folio_large_nr_pages(folio);
}
Workaround by open coding the range computation. Also, simplify the type
declarations for the relevant variables.
[ankur.a.arora@oracle.com: remove unneeded cast, per David]
Link: https://lkml.kernel.org/r/20260206223801.2617497-1-ankur.a.arora@oracle.com
Link: https://lkml.kernel.org/r/20260206223801.2617497-1-ankur.a.arora@oracle.com
Link: https://lkml.kernel.org/r/20260128185943.2397128-1-ankur.a.arora@oracle.com
Fixes: 93552c9a3350 ("mm: folio_zero_user: cache neighbouring pages")
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202601240453.QCjgGdJa-lkp@intel.com/
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Li Zhe <lizhe.67@bytedance.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The preferred demotion node (migration_target_control.nid) should be the
one closest to the source node to minimize migration latency. Currently,
a discrepancy exists where demote_folio_list() randomly selects an allowed
node if the preferred node from next_demotion_node() is not set in
mems_effective.
To address it, update next_demotion_node() to select a preferred target
against allowed nodes; and to return the closest demotion target if all
preferred nodes are not in mems_effective via next_demotion_node().
It ensures that the preferred demotion target is consistently the closest
available node to the source node.
[akpm@linux-foundation.org: fix comment typo, per Shakeel]
Link: https://lkml.kernel.org/r/20260114205305.2869796-3-bingjiao@google.com
Signed-off-by: Bing Jiao <bingjiao@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "mm/vmscan: fix demotion targets checks in reclaim/demotion",
v9.
This patch series addresses two issues in demote_folio_list(),
can_demote(), and next_demotion_node() in reclaim/demotion.
1. demote_folio_list() and can_demote() do not correctly check
demotion target against cpuset.mems_effective, which will cause (a)
pages to be demoted to not-allowed nodes and (b) pages fail demotion
even if the system still has allowed demotion nodes.
Patch 1 fixes this bug by updating cpuset_node_allowed() and
mem_cgroup_node_allowed() to return effective_mems, allowing directly
logic-and operation against demotion targets.
2. next_demotion_node() returns a preferred demotion target, but it
does not check the node against allowed nodes.
Patch 2 ensures that next_demotion_node() filters against the allowed
node mask and selects the closest demotion target to the source node.
This patch (of 2):
Fix two bugs in demote_folio_list() and can_demote() due to incorrect
demotion target checks against cpuset.mems_effective in reclaim/demotion.
Commit 7d709f49babc ("vmscan,cgroup: apply mems_effective to reclaim")
introduces the cpuset.mems_effective check and applies it to can_demote().
However:
1. It does not apply this check in demote_folio_list(), which leads
to situations where pages are demoted to nodes that are
explicitly excluded from the task's cpuset.mems.
2. It checks only the nodes in the immediate next demotion hierarchy
and does not check all allowed demotion targets in can_demote().
This can cause pages to never be demoted if the nodes in the next
demotion hierarchy are not set in mems_effective.
These bugs break resource isolation provided by cpuset.mems. This is
visible from userspace because pages can either fail to be demoted
entirely or are demoted to nodes that are not allowed in multi-tier memory
systems.
To address these bugs, update cpuset_node_allowed() and
mem_cgroup_node_allowed() to return effective_mems, allowing directly
logic-and operation against demotion targets. Also update can_demote()
and demote_folio_list() accordingly.
Bug 1 reproduction:
Assume a system with 4 nodes, where nodes 0-1 are top-tier and
nodes 2-3 are far-tier memory. All nodes have equal capacity.
Test script:
echo 1 > /sys/kernel/mm/numa/demotion_enabled
mkdir /sys/fs/cgroup/test
echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control
echo "0-2" > /sys/fs/cgroup/test/cpuset.mems
echo $$ > /sys/fs/cgroup/test/cgroup.procs
swapoff -a
# Expectation: Should respect node 0-2 limit.
# Observation: Node 3 shows significant allocation (MemFree drops)
stress-ng --oomable --vm 1 --vm-bytes 150% --mbind 0,1
Bug 2 reproduction:
Assume a system with 6 nodes, where nodes 0-2 are top-tier,
node 3 is a far-tier node, and nodes 4-5 are the farthest-tier nodes.
All nodes have equal capacity.
Test script:
echo 1 > /sys/kernel/mm/numa/demotion_enabled
mkdir /sys/fs/cgroup/test
echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control
echo "0-2,4-5" > /sys/fs/cgroup/test/cpuset.mems
echo $$ > /sys/fs/cgroup/test/cgroup.procs
swapoff -a
# Expectation: Pages are demoted to Nodes 4-5
# Observation: No pages are demoted before oom.
stress-ng --oomable --vm 1 --vm-bytes 150% --mbind 0,1,2
Link: https://lkml.kernel.org/r/20260114205305.2869796-1-bingjiao@google.com
Link: https://lkml.kernel.org/r/20260114205305.2869796-2-bingjiao@google.com
Fixes: 7d709f49babc ("vmscan,cgroup: apply mems_effective to reclaim")
Signed-off-by: Bing Jiao <bingjiao@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When CONFIG_DEBUG_OBJECTS_FREE is enabled,
debug_check_no_{obj,locks}_freed() functions are called.
Since both of them spin on a lock, they are not safe to be called if the
FPI_TRYLOCK flag is specified. This leads to a lockdep splat:
================================
WARNING: inconsistent lock state
6.19.0-rc5-slab-for-next+ #326 Tainted: G N
--------------------------------
inconsistent {INITIAL USE} -> {IN-NMI} usage.
kunit_try_catch/9046 [HC2[2]:SC0[0]:HE0:SE1] takes:
ffffffff84ed6bf8 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed+0xe0/0x300
{INITIAL USE} state was registered at:
lock_acquire+0xd9/0x2f0
_raw_spin_lock_irqsave+0x4c/0x80
__debug_object_init+0x9d/0x1f0
debug_object_init+0x34/0x50
__init_work+0x28/0x40
init_cgroup_housekeeping+0x151/0x210
init_cgroup_root+0x3d/0x140
cgroup_init_early+0x30/0x240
start_kernel+0x3e/0xcd0
x86_64_start_reservations+0x18/0x30
x86_64_start_kernel+0xf3/0x140
common_startup_64+0x13e/0x148
irq event stamp: 2998
hardirqs last enabled at (2997): [<ffffffff8298b77a>] exc_nmi+0x11a/0x240
hardirqs last disabled at (2998): [<ffffffff8298b991>] sysvec_irq_work+0x11/0x110
softirqs last enabled at (1416): [<ffffffff813c1f72>] __irq_exit_rcu+0x132/0x1c0
softirqs last disabled at (1303): [<ffffffff813c1f72>] __irq_exit_rcu+0x132/0x1c0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&obj_hash[i].lock);
<Interrupt>
lock(&obj_hash[i].lock);
*** DEADLOCK ***
Rename free_pages_prepare() to __free_pages_prepare(), add an fpi_t
parameter, and skip those checks if FPI_TRYLOCK is set. To keep the fpi_t
definition in mm/page_alloc.c, add a wrapper function free_pages_prepare()
that always passes FPI_NONE and use it in mm/compaction.c.
Link: https://lkml.kernel.org/r/20260209062639.16577-1-harry.yoo@oracle.com
Fixes: 8c57b687e833 ("mm, bpf: Introduce free_pages_nolock()")
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit a833a693a490 ("mm: hugetlb: fix incorrect fallback for subpool")
fixed an underflow error for hstate->resv_huge_pages caused by incorrectly
attributing globally requested pages to the subpool's reservation.
Unfortunately, this fix also introduced the opposite problem, which would
leave spool->used_hpages elevated if the globally requested pages could
not be acquired. This is because while a subpool's reserve pages only
accounts for what is requested and allocated from the subpool, its "used"
counter keeps track of what is consumed in total, both from the subpool
and globally. Thus, we need to adjust spool->used_hpages in the other
direction, and make sure that globally requested pages are uncharged from
the subpool's used counter.
Each failed allocation attempt increments the used_hpages counter by how
many pages were requested from the global pool. Ultimately, this renders
the subpool unusable, as used_hpages approaches the max limit.
The issue can be reproduced as follows:
1. Allocate 4 hugetlb pages
2. Create a hugetlb mount with max=4, min=2
3. Consume 2 pages globally
4. Request 3 pages from the subpool (2 from subpool + 1 from global)
4.1 hugepage_subpool_get_pages(spool, 3) succeeds.
used_hpages += 3
4.2 hugetlb_acct_memory(h, 1) fails: no global pages left
used_hpages -= 2
5. Subpool now has used_hpages = 1, despite not being able to
successfully allocate any hugepages. It believes it can now only
allocate 3 more hugepages, not 4.
With each failed allocation attempt incrementing the used counter, the
subpool eventually reaches a point where its used counter equals its
max counter. At that point, any future allocations that try to
allocate hugeTLB pages from the subpool will fail, despite the subpool
not having any of its hugeTLB pages consumed by any user.
Once this happens, there is no way to make the subpool usable again,
since there is no way to decrement the used counter as no process is
really consuming the hugeTLB pages.
The underflow issue that the original commit fixes still remains fixed
as well.
Without this fix, used_hpages would keep on leaking if
hugetlb_acct_memory() fails.
Link: https://lkml.kernel.org/r/20260116204037.2270096-1-joshua.hahnjy@gmail.com
Fixes: a833a693a490 ("mm: hugetlb: fix incorrect fallback for subpool")
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Usama Arif <usama.arif@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Ma Wupeng <mawupeng1@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves
disk space by teaching ocfs2 to reclaim suballocator block group
space (Heming Zhao)
- "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the
ARRAY_END() macro and uses it in various places (Alejandro Colomar)
- "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes
the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the
page size (Pnina Feder)
- "kallsyms: Prevent invalid access when showing module buildid" cleans
up kallsyms code related to module buildid and fixes an invalid
access crash when printing backtraces (Petr Mladek)
- "Address page fault in ima_restore_measurement_list()" fixes a
kexec-related crash that can occur when booting the second-stage
kernel on x86 (Harshit Mogalapalli)
- "kho: ABI headers and Documentation updates" updates the kexec
handover ABI documentation (Mike Rapoport)
- "Align atomic storage" adds the __aligned attribute to atomic_t and
atomic64_t definitions to get natural alignment of both types on
csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain)
- "kho: clean up page initialization logic" simplifies the page
initialization logic in kho_restore_page() (Pratyush Yadav)
- "Unload linux/kernel.h" moves several things out of kernel.h and into
more appropriate places (Yury Norov)
- "don't abuse task_struct.group_leader" removes the usage of
->group_leader when it is "obviously unnecessary" (Oleg Nesterov)
- "list private v2 & luo flb" adds some infrastructure improvements to
the live update orchestrator (Pasha Tatashin)
* tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits)
watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency
procfs: fix missing RCU protection when reading real_parent in do_task_stat()
watchdog/softlockup: fix sample ring index wrap in need_counting_irqs()
kcsan, compiler_types: avoid duplicate type issues in BPF Type Format
kho: fix doc for kho_restore_pages()
tests/liveupdate: add in-kernel liveupdate test
liveupdate: luo_flb: introduce File-Lifecycle-Bound global state
liveupdate: luo_file: Use private list
list: add kunit test for private list primitives
list: add primitives for private list manipulations
delayacct: fix uapi timespec64 definition
panic: add panic_force_cpu= parameter to redirect panic to a specific CPU
netclassid: use thread_group_leader(p) in update_classid_task()
RDMA/umem: don't abuse current->group_leader
drm/pan*: don't abuse current->group_leader
drm/amd: kill the outdated "Only the pthreads threading model is supported" checks
drm/amdgpu: don't abuse current->group_leader
android/binder: use same_thread_group(proc->tsk, current) in binder_mmap()
android/binder: don't abuse current->group_leader
kho: skip memoryless NUMA nodes when reserving scratch areas
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "powerpc/64s: do not re-activate batched TLB flush" makes
arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)
It adds a generic enter/leave layer and switches architectures to use
it. Various hacks were removed in the process.
- "zram: introduce compressed data writeback" implements data
compression for zram writeback (Richard Chang and Sergey Senozhatsky)
- "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
page ranges for hugepages. Large improvements during demand faulting
are demonstrated (David Hildenbrand)
- "memcg cleanups" tidies up some memcg code (Chen Ridong)
- "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
stats" improves DAMOS stat's provided information, deterministic
control, and readability (SeongJae Park)
- "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
issues in the hugetlb cgroup charging selftests (Li Wang)
- "Fix va_high_addr_switch.sh test failure - again" addresses several
issues in the va_high_addr_switch test (Chunyu Hu)
- "mm/damon/tests/core-kunit: extend existing test scenarios" improves
the KUnit test coverage for DAMON (Shu Anzai)
- "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
transiently return -EAGAIN (Shivank Garg)
- "arch, mm: consolidate hugetlb early reservation" reworks and
consolidates a pile of straggly code related to reservation of
hugetlb memory from bootmem and creation of CMA areas for hugetlb
(Mike Rapoport)
- "mm: clean up anon_vma implementation" cleans up the anon_vma
implementation in various ways (Lorenzo Stoakes)
- "tweaks for __alloc_pages_slowpath()" does a little streamlining of
the page allocator's slowpath code (Vlastimil Babka)
- "memcg: separate private and public ID namespaces" cleans up the
memcg ID code and prevents the internal-only private IDs from being
exposed to userspace (Shakeel Butt)
- "mm: hugetlb: allocate frozen gigantic folio" cleans up the
allocation of frozen folios and avoids some atomic refcount
operations (Kefeng Wang)
- "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
of memory betewwn the active and inactive LRUs and adds auto-tuning
of the ratio-based quotas and of monitoring intervals (SeongJae Park)
- "Support page table check on PowerPC" makes
CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)
- "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
nodes_and() and nodes_andnot() propagate the return values from the
underlying bit operations, enabling some cleanup in calling code
(Yury Norov)
- "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
some DAMON internal interfaces (SeongJae Park)
- "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
in khupaged and fixes a scan limit accounting issue (Shivank Garg)
- "mm: balloon infrastructure cleanups" goes to town on the balloon
infrastructure and its page migration function. Mainly cleanups, also
some locking simplification (David Hildenbrand)
- "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
additional tracepoints to the page reclaim code (Jiayuan Chen)
- "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
part of Marco's kernel-wide migration from the legacy workqueue APIs
over to the preferred unbound workqueues (Marco Crivellari)
- "Various mm kselftests improvements/fixes" provides various unrelated
improvements/fixes for the mm kselftests (Kevin Brodsky)
- "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
folio allocation, mainly by avoiding unnecessary work in
pfn_range_valid_contig() (Kefeng Wang)
- "selftests/damon: improve leak detection and wss estimation
reliability" improves the reliability of two of the DAMON selftests
(SeongJae Park)
- "mm/damon: cleanup kdamond, damon_call(), damos filter and
DAMON_MIN_REGION" does some cleanup work in the core DAMON code
(SeongJae Park)
- "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
performs maintenance work on the DAMON documentation (SeongJae Park)
- "mm: add and use vma_assert_stabilised() helper" refactors and cleans
up the core VMA code. The main aim here is to be able to use the mmap
write lock's lockdep state to perform various assertions regarding
the locking which the VMA code requires (Lorenzo Stoakes)
- "mm, swap: swap table phase II: unify swapin use" removes some old
swap code (swap cache bypassing and swap synchronization) which
wasn't working very well. Various other cleanups and simplifications
were made. The end result is a 20% speedup in one benchmark (Kairui
Song)
- "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
available on 64-bit alpha, loongarch, mips, parisc, and um. Various
cleanups were performed along the way (Qi Zheng)
* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
mm/memory: handle non-split locks correctly in zap_empty_pte_table()
mm: move pte table reclaim code to memory.c
mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
um: mm: enable MMU_GATHER_RCU_TABLE_FREE
parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
zsmalloc: make common caches global
mm: add SPDX id lines to some mm source files
mm/zswap: use %pe to print error pointers
mm/vmscan: use %pe to print error pointers
mm/readahead: fix typo in comment
mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
mm: refactor vma_map_pages to use vm_insert_pages
mm/damon: unify address range representation with damon_addr_range
mm/cma: replace snprintf with strscpy in cma_new_area
...
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Pull fsverity updates from Eric Biggers:
"fsverity cleanups, speedup, and memory usage optimization from
Christoph Hellwig:
- Move some logic into common code
- Fix btrfs to reject truncates of fsverity files
- Improve the readahead implementation
- Store each inode's fsverity_info in a hash table instead of using a
pointer in the filesystem-specific part of the inode.
This optimizes for memory usage in the usual case where most files
don't have fsverity enabled.
- Look up the fsverity_info fewer times during verification, to
amortize the hash table overhead"
* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux:
fsverity: remove inode from fsverity_verification_ctx
fsverity: use a hashtable to find the fsverity_info
btrfs: consolidate fsverity_info lookup
f2fs: consolidate fsverity_info lookup
ext4: consolidate fsverity_info lookup
fs: consolidate fsverity_info lookup in buffer.c
fsverity: push out fsverity_info lookup
fsverity: deconstify the inode pointer in struct fsverity_info
fsverity: kick off hash readahead at data I/O submission time
ext4: move ->read_folio and ->readahead to readpage.c
readahead: push invalidate_lock out of page_cache_ra_unbounded
fsverity: don't issue readahead for non-ENOENT errors from __filemap_get_folio
fsverity: start consolidating pagecache code
fsverity: pass struct file to ->write_merkle_tree_block
f2fs: don't build the fsverity work handler for !CONFIG_FS_VERITY
ext4: don't build the fsverity work handler for !CONFIG_FS_VERITY
fs,fsverity: clear out fsverity_info from common code
fs,fsverity: reject size changes on fsverity files in setattr_prepare
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git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux
Pull iommu updates from Joerg Roedel:
"Core changes:
- Rust bindings for IO-pgtable code
- IOMMU page allocation debugging support
- Disable ATS during PCI resets
Intel VT-d changes:
- Skip dev-iotlb flush for inaccessible PCIe device
- Flush cache for PASID table before using it
- Use right invalidation method for SVA and NESTED domains
- Ensure atomicity in context and PASID entry updates
AMD-Vi changes:
- Support for nested translations
- Other minor improvements
ARM-SMMU-v2 changes:
- Configure SoC-specific prefetcher settings for Qualcomm's "MDSS"
ARM-SMMU-v3 changes:
- Improve CMDQ locking fairness for pathetically small queue sizes
- Remove tracking of the IAS as this is only relevant for AArch32 and
was causing C_BAD_STE errors
- Add device-tree support for NVIDIA's CMDQV extension
- Allow some hitless transitions for the 'MEV' and 'EATS' STE fields
- Don't disable ATS for nested S1-bypass nested domains
- Additions to the kunit selftests"
* tag 'iommu-updates-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (54 commits)
iommupt: Always add IOVA range to iotlb_gather in gather_range_pages()
iommu/amd: serialize sequence allocation under concurrent TLB invalidations
iommu/amd: Fix type of type parameter to amd_iommufd_hw_info()
iommu/arm-smmu-v3: Do not set disable_ats unless vSTE is Translate
iommu/arm-smmu-v3-test: Add nested s1bypass/s1dssbypass coverage
iommu/arm-smmu-v3: Mark EATS_TRANS safe when computing the update sequence
iommu/arm-smmu-v3: Mark STE MEV safe when computing the update sequence
iommu/arm-smmu-v3: Add update_safe bits to fix STE update sequence
iommu/arm-smmu-v3: Add device-tree support for CMDQV driver
iommu/tegra241-cmdqv: Decouple driver from ACPI
iommu/arm-smmu-qcom: Restore ACTLR settings for MDSS on sa8775p
iommu/vt-d: Fix race condition during PASID entry replacement
iommu/vt-d: Clear Present bit before tearing down context entry
iommu/vt-d: Clear Present bit before tearing down PASID entry
iommu/vt-d: Flush piotlb for SVM and Nested domain
iommu/vt-d: Flush cache for PASID table before using it
iommu/vt-d: Flush dev-IOTLB only when PCIe device is accessible in scalable mode
iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode
rust: iommu: fix `srctree` link warning
rust: iommu: fix Rust formatting
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
- The percpu sheaves caching layer was introduced as opt-in in 6.18 and
now we enable it for all caches and remove the previous cpu (partial)
slab caching mechanism.
Besides the lower locking overhead and much more likely fastpath when
freeing, this removes the rather complicated code related to the cpu
slab lockless fastpaths (using this_cpu_try_cmpxchg128/64) and all
its complications for PREEMPT_RT or kmalloc_nolock().
The lockless slab freelist+counters update operation using
try_cmpxchg128/64 remains and is crucial for freeing remote NUMA
objects, and to allow flushing objects from sheaves to slabs mostly
without the node list_lock (Vlastimil Babka)
- Eliminate slabobj_ext metadata overhead when possible. Instead of
using kmalloc() to allocate the array for memcg and/or allocation
profiling tag pointers, use leftover space in a slab or per-object
padding due to alignment (Harry Yoo)
- Various followup improvements to the above (Hao Li)
* tag 'slab-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (39 commits)
slub: let need_slab_obj_exts() return false if SLAB_NO_OBJ_EXT is set
mm/slab: only allow SLAB_OBJ_EXT_IN_OBJ for unmergeable caches
mm/slab: place slabobj_ext metadata in unused space within s->size
mm/slab: move [__]ksize and slab_ksize() to mm/slub.c
mm/slab: save memory by allocating slabobj_ext array from leftover
mm/memcontrol,alloc_tag: handle slabobj_ext access under KASAN poison
mm/slab: use stride to access slabobj_ext
mm/slab: abstract slabobj_ext access via new slab_obj_ext() helper
ext4: specify the free pointer offset for ext4_inode_cache
mm/slab: allow specifying free pointer offset when using constructor
mm/slab: use unsigned long for orig_size to ensure proper metadata align
slub: clarify object field layout comments
mm/slab: avoid allocating slabobj_ext array from its own slab
slub: avoid list_lock contention from __refill_objects_any()
mm/slub: cleanup and repurpose some stat items
mm/slub: remove DEACTIVATE_TO_* stat items
slab: remove frozen slab checks from __slab_free()
slab: update overview comments
slab: refill sheaves from all nodes
slab: remove unused PREEMPT_RT specific macros
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cpuset changes:
- Continue separating v1 and v2 implementations by moving more
v1-specific logic into cpuset-v1.c
- Improve partition handling. Sibling partitions are no longer
invalidated on cpuset.cpus conflict, cpuset.cpus changes no longer
fail in v2, and effective_xcpus computation is made consistent
- Fix partition effective CPUs overlap that caused a warning on
cpuset removal when sibling partitions shared CPUs
- Increase the maximum cgroup subsystem count from 16 to 32 to
accommodate future subsystem additions
- Misc cleanups and selftest improvements including switching to
css_is_online() helper, removing dead code and stale documentation
references, using lockdep_assert_cpuset_lock_held() consistently, and
adding polling helpers for asynchronously updated cgroup statistics
* tag 'cgroup-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: fix overlap of partition effective CPUs
cgroup: increase maximum subsystem count from 16 to 32
cgroup: Remove stale cpu.rt.max reference from documentation
cpuset: replace direct lockdep_assert_held() with lockdep_assert_cpuset_lock_held()
cgroup/cpuset: Move the v1 empty cpus/mems check to cpuset1_validate_change()
cgroup/cpuset: Don't invalidate sibling partitions on cpuset.cpus conflict
cgroup/cpuset: Don't fail cpuset.cpus change in v2
cgroup/cpuset: Consistently compute effective_xcpus in update_cpumasks_hier()
cgroup/cpuset: Streamline rm_siblings_excl_cpus()
cpuset: remove dead code in cpuset-v1.c
cpuset: remove v1-specific code from generate_sched_domains
cpuset: separate generate_sched_domains for v1 and v2
cpuset: move update_domain_attr_tree to cpuset_v1.c
cpuset: add cpuset1_init helper for v1 initialization
cpuset: add cpuset1_online_css helper for v1-specific operations
cpuset: add lockdep_assert_cpuset_lock_held helper
cpuset: Remove unnecessary checks in rebuild_sched_domains_locked
cgroup: switch to css_is_online() helper
selftests: cgroup: Replace sleep with cg_read_key_long_poll() for waiting on nr_dying_descendants
selftests: cgroup: make test_memcg_sock robust against delayed sock stats
...
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https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
- gmap rewrite: completely new memory management for kvm/s390
- vSIE improvement
- maintainership change for s390 vfio-pci
- small quality of life improvement for protected guests
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If hmm_range_fault() fails a folio_trylock() in do_swap_page,
trying to acquire the lock of a device-private folio for migration,
to ram, the function will spin until it succeeds grabbing the lock.
However, if the process holding the lock is depending on a work
item to be completed, which is scheduled on the same CPU as the
spinning hmm_range_fault(), that work item might be starved and
we end up in a livelock / starvation situation which is never
resolved.
This can happen, for example if the process holding the
device-private folio lock is stuck in
migrate_device_unmap()->lru_add_drain_all()
sinc lru_add_drain_all() requires a short work-item
to be run on all online cpus to complete.
A prerequisite for this to happen is:
a) Both zone device and system memory folios are considered in
migrate_device_unmap(), so that there is a reason to call
lru_add_drain_all() for a system memory folio while a
folio lock is held on a zone device folio.
b) The zone device folio has an initial mapcount > 1 which causes
at least one migration PTE entry insertion to be deferred to
try_to_migrate(), which can happen after the call to
lru_add_drain_all().
c) No or voluntary only preemption.
This all seems pretty unlikely to happen, but indeed is hit by
the "xe_exec_system_allocator" igt test.
Resolve this by waiting for the folio to be unlocked if the
folio_trylock() fails in do_swap_page().
Rename migration_entry_wait_on_locked() to
softleaf_entry_wait_unlock() and update its documentation to
indicate the new use-case.
Future code improvements might consider moving
the lru_add_drain_all() call in migrate_device_unmap() to be
called *after* all pages have migration entries inserted.
That would eliminate also b) above.
v2:
- Instead of a cond_resched() in hmm_range_fault(),
eliminate the problem by waiting for the folio to be unlocked
in do_swap_page() (Alistair Popple, Andrew Morton)
v3:
- Add a stub migration_entry_wait_on_locked() for the
!CONFIG_MIGRATION case. (Kernel Test Robot)
v4:
- Rename migrate_entry_wait_on_locked() to
softleaf_entry_wait_on_locked() and update docs (Alistair Popple)
v5:
- Add a WARN_ON_ONCE() for the !CONFIG_MIGRATION
version of softleaf_entry_wait_on_locked().
- Modify wording around function names in the commit message
(Andrew Morton)
Suggested-by: Alistair Popple <apopple@nvidia.com>
Fixes: 1afaeb8293c9 ("mm/migrate: Trylock device page in do_swap_page")
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: linux-mm@kvack.org
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: <stable@vger.kernel.org> # v6.15+
Reviewed-by: John Hubbard <jhubbard@nvidia.com> #v3
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Link: https://patch.msgid.link/20260210115653.92413-1-thomas.hellstrom@linux.intel.com
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