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2026-01-27mm/slab: make caches with sheaves mergeableVlastimil Babka
Before enabling sheaves for all caches (with automatically determined capacity), their enablement should no longer prevent merging of caches. Limit this merge prevention only to caches that were created with a specific sheaf capacity, by adding the SLAB_NO_MERGE flag to them. Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-01-27mm/slab: move and refactor __kmem_cache_alias()Vlastimil Babka
Move __kmem_cache_alias() to slab_common.c since it's called by __kmem_cache_create_args() and calls find_mergeable() that both are in this file. We can remove two slab.h declarations and make them static. Instead declare sysfs_slab_alias() from slub.c so that __kmem_cache_alias() can keep calling it. Add args parameter to __kmem_cache_alias() and find_mergeable() instead of align and ctor. With that we can also move the checks for usersize and sheaf_capacity there from __kmem_cache_create_args() and make the result more symmetric with slab_unmergeable(). No functional changes intended. Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-01-27slab: add SLAB_CONSISTENCY_CHECKS to SLAB_NEVER_MERGEVlastimil Babka
All the debug flags prevent merging, except SLAB_CONSISTENCY_CHECKS. This is suboptimal because this flag (like any debug flags) prevents the usage of any fastpaths, and thus affect performance of any aliased cache. Also the objects from an aliased cache than the one specified for debugging could also interfere with the debugging efforts. Fix this by adding the whole SLAB_DEBUG_FLAGS collection to SLAB_NEVER_MERGE instead of individual debug flags, so it now also includes SLAB_CONSISTENCY_CHECKS. Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-01-27mm/slab: fix false lockdep warning in __kfree_rcu_sheaf()Harry Yoo
kvfree_call_rcu() can be called while holding a raw_spinlock_t. Since __kfree_rcu_sheaf() may acquire a spinlock_t (which becomes a sleeping lock on PREEMPT_RT) and violate lock nesting rules, kvfree_call_rcu() bypasses the sheaves layer entirely on PREEMPT_RT. However, lockdep still complains about acquiring spinlock_t while holding raw_spinlock_t, even on !PREEMPT_RT where spinlock_t is a spinning lock. This causes a false lockdep warning [1]: ============================= [ BUG: Invalid wait context ] 6.19.0-rc6-next-20260120 #21508 Not tainted ----------------------------- migration/1/23 is trying to lock: ffff8afd01054e98 (&barn->lock){..-.}-{3:3}, at: barn_get_empty_sheaf+0x1d/0xb0 other info that might help us debug this: context-{5:5} 3 locks held by migration/1/23: #0: ffff8afd01fd89a8 (&p->pi_lock){-.-.}-{2:2}, at: __balance_push_cpu_stop+0x3f/0x200 #1: ffffffff9f15c5c8 (rcu_read_lock){....}-{1:3}, at: cpuset_cpus_allowed_fallback+0x27/0x250 #2: ffff8afd1f470be0 ((local_lock_t *)&pcs->lock){+.+.}-{3:3}, at: __kfree_rcu_sheaf+0x52/0x3d0 stack backtrace: CPU: 1 UID: 0 PID: 23 Comm: migration/1 Not tainted 6.19.0-rc6-next-20260120 #21508 PREEMPTLAZY Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Stopper: __balance_push_cpu_stop+0x0/0x200 <- balance_push+0x118/0x170 Call Trace: <TASK> __dump_stack+0x22/0x30 dump_stack_lvl+0x60/0x80 dump_stack+0x19/0x24 __lock_acquire+0xd3a/0x28e0 ? __lock_acquire+0x5a9/0x28e0 ? __lock_acquire+0x5a9/0x28e0 ? barn_get_empty_sheaf+0x1d/0xb0 lock_acquire+0xc3/0x270 ? barn_get_empty_sheaf+0x1d/0xb0 ? __kfree_rcu_sheaf+0x52/0x3d0 _raw_spin_lock_irqsave+0x47/0x70 ? barn_get_empty_sheaf+0x1d/0xb0 barn_get_empty_sheaf+0x1d/0xb0 ? __kfree_rcu_sheaf+0x52/0x3d0 __kfree_rcu_sheaf+0x19f/0x3d0 kvfree_call_rcu+0xaf/0x390 set_cpus_allowed_force+0xc8/0xf0 [...] </TASK> This wasn't triggered until sheaves were enabled for all slab caches, since kfree_rcu() wasn't being called with a raw spinlock held for caches with sheaves (vma, maple node). As suggested by Vlastimil Babka, fix this by using a lockdep map with LD_WAIT_CONFIG wait type to tell lockdep that acquiring spinlock_t is valid in this case, as those spinlocks won't be used on PREEMPT_RT. Note that kfree_rcu_sheaf_map should be acquired using _try() variant, otherwise the acquisition of the lockdep map itself will trigger an invalid wait context warning. Reported-by: Paul E. McKenney <paulmck@kernel.org> Closes: https://lore.kernel.org/linux-mm/c858b9af-2510-448b-9ab3-058f7b80dd42@paulmck-laptop [1] Fixes: ec66e0d59952 ("slab: add sheaf support for batching kfree_rcu() operations") Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-01-27mm/slab: add rcu_barrier() to kvfree_rcu_barrier_on_cache()Vlastimil Babka
After we submit the rcu_free sheaves to call_rcu() we need to make sure the rcu callbacks complete. kvfree_rcu_barrier() does that via flush_all_rcu_sheaves() but kvfree_rcu_barrier_on_cache() doesn't. Fix that. This currently causes no issues because the caches with sheaves we have are never destroyed. The problem flagged by kernel test robot was reported for a patch that enables sheaves for (almost) all caches, and occurred only with CONFIG_KASAN. Harry Yoo found the root cause [1]: It turns out the object freed by sheaf_flush_unused() was in KASAN percpu quarantine list (confirmed by dumping the list) by the time __kmem_cache_shutdown() returns an error. Quarantined objects are supposed to be flushed by kasan_cache_shutdown(), but things go wrong if the rcu callback (rcu_free_sheaf_nobarn()) is processed after kasan_cache_shutdown() finishes. That's why rcu_barrier() in __kmem_cache_shutdown() didn't help, because it's called after kasan_cache_shutdown(). Calling rcu_barrier() in kvfree_rcu_barrier_on_cache() guarantees that it'll be added to the quarantine list before kasan_cache_shutdown() is called. So it's a valid fix! [1] https://lore.kernel.org/all/aWd6f3jERlrB5yeF@hyeyoo/ Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202601121442.c530bed3-lkp@intel.com Fixes: 0f35040de593 ("mm/slab: introduce kvfree_rcu_barrier_on_cache() for cache destruction") Cc: stable@vger.kernel.org Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Tested-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-01-27slab: replace cache_from_obj() with inline checksVlastimil Babka
Eric Dumazet has noticed cache_from_obj() is not inlined with clang and suggested splitting it into two functions, where the smaller inlined one assumes the fastpath is !CONFIG_SLAB_FREELIST_HARDENED. However most distros enable it these days and so this would likely add a function call to the object free fastpaths. Instead take a step back and consider that cache_from_obj() is a relict from when memcgs created their separate kmem_cache copies, as the outdated comment in build_detached_freelist() reminds us. Meanwhile hardening/debugging had reused cache_from_obj() to validate that the freed object really belongs to a slab from the cache we think we are freeing from. In build_detached_freelist() simply remove this, because it did not handle the NULL result from cache_from_obj() failure properly, nor validate objects (for the NULL slab->slab_cache pointer) when called via kfree_bulk(). If anyone is motivated to implement it properly, it should be possible in a similar way to kmem_cache_free(). In kmem_cache_free(), do the hardening/debugging checks directly so they are inlined by definition and virt_to_slab(obj) is performed just once. In case they failed, call a newly introduced warn_free_bad_obj() that performs the warnings outside of the fastpath, and leak the object. As an intentional change, leak the object when slab->slab_cache differs from the cache given to kmem_cache_free(). Previously we would only leak when the object is not in a valid slab page or the slab->slab_cache pointer is NULL, and otherwise trust the slab->slab_cache over the kmem_cache_free() argument. But if those differ, it means something went wrong enough that it's best not to continue freeing. As a result the fastpath should be inlined in all configs and the warnings are moved away. Reported-by: Eric Dumazet <edumazet@google.com> Closes: https://lore.kernel.org/all/20260115130642.3419324-1-edumazet@google.com/ Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Hao Li <hao.li@linux.dev> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-01-26mm/damon/reclaim: use damon_kdamond_pid()SeongJae Park
DAMON_RECLAIM directly uses damon_ctx->kdamond field with manual synchronization using damon_ctx->kdamond_lock, to get the pid of the kdamond. Use a new dedicated function for the purpose, namely damon_kdamond_pid(), since that doesn't require manual and error-prone synchronization. Link: https://lkml.kernel.org/r/20260115152047.68415-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/lru_sort: use damon_kdamond_pid()SeongJae Park
DAMON_LRU_SORT directly uses damon_ctx->kdamond field with manual synchronization using damon_ctx->kdamond_lock, to get the pid of the kdamond. Use a new dedicated function for the purpose, namely damon_kdamond_pid(), since that doesn't require manual and error-prone synchronization. Link: https://lkml.kernel.org/r/20260115152047.68415-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/sysfs: use damon_kdamond_pid()SeongJae Park
DAMON sysfs interface directly uses damon_ctx->kdamond field with manual synchronization using damon_ctx->kdamond_lock, to get the pid of the kdamond. Use a new dedicated function for the purpose, namely damon_kdamond_pid(), since that doesn't require manual and error-prone synchronization. Avoid use of kdamond_lock outside of the core. Link: https://lkml.kernel.org/r/20260115152047.68415-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/core: implement damon_kdamond_pid()SeongJae Park
Patch series "mm/damon: hide kdamond and kdamond_lock from API callers". 'kdamond' and 'kdamond_lock' fields initially exposed to DAMON API callers for flexible synchronization and use cases. As DAMON API became somewhat complicated compared to the early days, Keeping those exposed could only encourage the API callers to invent more creative but complicated and difficult-to-debug use cases. Fortunately DAMON API callers didn't invent that many creative use cases. There exist only two use cases of 'kdamond' and 'kdamond_lock'. Finding whether the kdamond is actively running, and getting the pid of the kdamond. For the first use case, a dedicated API function, namely 'damon_is_running()' is provided, and all DAMON API callers are using the function for the use case. Hence only the second use case is where the fields are directly being used by DAMON API callers. To prevent future invention of complicated and erroneous use cases of the fields, hide the fields from the API callers. For that, provide new dedicated DAMON API functions for the remaining use case, namely damon_kdamond_pid(), migrate DAMON API callers to use the new function, and mark the fields as private fields. This patch (of 5): 'kdamond' and 'kdamond_lock' are directly being used by DAMON API callers for getting the pid of the corresponding kdamond. To discourage invention of creative but complicated and erroneous new usages of the fields that require careful synchronization, implement a new API function that can simply be used without the manual synchronizations. Link: https://lkml.kernel.org/r/20260115152047.68415-1-sj@kernel.org Link: https://lkml.kernel.org/r/20260115152047.68415-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: use nodes_and() return value to simplify client codeYury Norov
establish_demotion_targets() and kernel_migrate_pages() call node_empty() immediately after calling nodes_and(). Now that nodes_and() return false if nodemask is empty, drop the latter. Link: https://lkml.kernel.org/r/20260114172217.861204-3-ynorov@nvidia.com Signed-off-by: Yury Norov <ynorov@nvidia.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Koutný <mkoutny@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: provide address parameter to p{te,md,ud}_user_accessible_page()Rohan McLure
On several powerpc platforms, a page table entry may not imply whether the relevant mapping is for userspace or kernelspace. Instead, such platforms infer this by the address which is being accessed. Add an additional address argument to each of these routines in order to provide support for page table check on powerpc. [ajd@linux.ibm.com: rebase on arm64 changes] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-9-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Ingo Molnar <mingo@kernel.org> # x86 Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Thomas Huth <thuth@redhat.com> Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/page_table_check: reinstate address parameter in ↵Rohan McLure
[__]page_table_check_pte_clear() This reverts commit aa232204c468 ("mm/page_table_check: remove unused parameter in [__]page_table_check_pte_clear"). Reinstate previously unused parameters for the purpose of supporting powerpc platforms, as many do not encode user/kernel ownership of the page in the pte, but instead in the address of the access. [ajd@linux.ibm.com: rebase, fix additional occurrence and loop handling] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-8-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Ingo Molnar <mingo@kernel.org> # x86 Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Thomas Huth <thuth@redhat.com> Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/page_table_check: reinstate address parameter in ↵Rohan McLure
[__]page_table_check_pmd_clear() This reverts commit 1831414cd729 ("mm/page_table_check: remove unused parameter in [__]page_table_check_pmd_clear"). Reinstate previously unused parameters for the purpose of supporting powerpc platforms, as many do not encode user/kernel ownership of the page in the pte, but instead in the address of the access. [ajd@linux.ibm.com: rebase on arm64 changes] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-7-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Ingo Molnar <mingo@kernel.org> # x86 Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Thomas Huth <thuth@redhat.com> Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/page_table_check: reinstate address parameter in ↵Rohan McLure
[__]page_table_check_pud_clear() This reverts commit 931c38e16499 ("mm/page_table_check: remove unused parameter in [__]page_table_check_pud_clear"). Reinstate previously unused parameters for the purpose of supporting powerpc platforms, as many do not encode user/kernel ownership of the page in the pte, but instead in the address of the access. [ajd@linux.ibm.com: rebase on arm64 changes] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-6-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Ingo Molnar <mingo@kernel.org> # x86 Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Thomas Huth <thuth@redhat.com> Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/page_table_check: provide addr parameter to page_table_check_ptes_set()Rohan McLure
To provide support for powerpc platforms, provide an addr parameter to the __page_table_check_ptes_set() and page_table_check_ptes_set() routines. This parameter is needed on some powerpc platforms which do not encode whether a mapping is for user or kernel in the pte. On such platforms, this can be inferred from the addr parameter. [ajd@linux.ibm.com: rebase on arm64 + riscv changes, update commit message] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-5-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Thomas Huth <thuth@redhat.com> Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/page_table_check: reinstate address parameter in ↵Rohan McLure
[__]page_table_check_pmd[s]_set() This reverts commit a3b837130b58 ("mm/page_table_check: remove unused parameter in [__]page_table_check_pmd_set"). Reinstate previously unused parameters for the purpose of supporting powerpc platforms, as many do not encode user/kernel ownership of the page in the pte, but instead in the address of the access. Apply this to __page_table_check_pmds_set(), page_table_check_pmd_set(), and the page_table_check_pmd_set() wrapper macro. [ajd@linux.ibm.com: rebase on arm64 + riscv changes, update commit message] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-4-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Ingo Molnar <mingo@kernel.org> # x86 Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Thomas Huth <thuth@redhat.com> Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/page_table_check: reinstate address parameter in ↵Rohan McLure
[__]page_table_check_pud[s]_set() This reverts commit 6d144436d954 ("mm/page_table_check: remove unused parameter in [__]page_table_check_pud_set"). Reinstate previously unused parameters for the purpose of supporting powerpc platforms, as many do not encode user/kernel ownership of the page in the pte, but instead in the address of the access. Apply this to __page_table_check_puds_set(), page_table_check_puds_set() and the page_table_check_pud_set() wrapper macro. [ajd@linux.ibm.com: rebase on riscv + arm64 changes, update commit message] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-3-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Ingo Molnar <mingo@kernel.org> # x86 Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Guo Weikang <guoweikang.kernel@gmail.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Thomas Huth <thuth@redhat.com> Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26migrate: replace RMP_ flags with TTU_ flagsMatthew Wilcox (Oracle)
Instead of translating between RMP_ and TTU_ flags, remove the RMP_ flags and just use the TTU_ flag space; there's plenty available. Possibly we should rename these to RMAP_ flags, and maybe even pass them in through rmap_walk_arg, but that can be done later. Link: https://lkml.kernel.org/r/20260109041345.3863089-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Jann Horn <jannh@google.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Ying Huang <ying.huang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/mempolicy: fix mpol_rebind_nodemask() for MPOL_F_NUMA_BALANCINGJinjiang Tu
commit bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes") adds new flag MPOL_F_NUMA_BALANCING to enable NUMA balancing for MPOL_BIND memory policy. When the cpuset of tasks changes, the mempolicy of the task is rebound by mpol_rebind_nodemask(). When MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES are both not set, the behaviour of rebinding should be same whenever MPOL_F_NUMA_BALANCING is set or not. So, when an application calls set_mempolicy() with MPOL_F_NUMA_BALANCING set but both MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES cleared, mempolicy.w.cpuset_mems_allowed should be set to cpuset_current_mems_allowed nodemask. However, in current implementation, mpol_store_user_nodemask() wrongly returns true, causing mempolicy->w.user_nodemask to be incorrectly set to the user-specified nodemask. Later, when the cpuset of the application changes, mpol_rebind_nodemask() ends up rebinding based on the user-specified nodemask rather than the cpuset_mems_allowed nodemask as intended. I can reproduce with the following steps in qemu with 4 NUMA nodes: 1. echo '+cpuset' > /sys/fs/cgroup/cgroup.subtree_control 2. mkdir /sys/fs/cgroup/test 3. ./reproducer & 4. cat /proc/$pid/numa_maps, the task is bound to NUMA 1 5. echo $pid > /sys/fs/cgroup/test/cgroup.procs 6. cat /proc/$pid/numa_maps, the task is bound to NUMA 0 now. The reproducer code: int main() { struct bitmask *bmp; int ret; bmp = numa_parse_nodestring("1"); ret = set_mempolicy(MPOL_BIND | MPOL_F_NUMA_BALANCING, bmp->maskp, bmp->size + 1); if (ret < 0) { perror("Failed to call set_mempolicy"); exit(-1); } while (1); return 0; } If I call set_mempolicy() without MPOL_F_NUMA_BALANCING in the reproducer code. After step 5, the task is still bound to NUMA 1. To fix this, only set mempolicy->w.user_nodemask to the user-specified nodemask if MPOL_F_STATIC_NODES or MPOL_F_RELATIVE_NODES is present. Link: https://lkml.kernel.org/r/20260120011018.1256654-1-tujinjiang@huawei.com Link: https://lkml.kernel.org/r/20251223110523.1161421-1-tujinjiang@huawei.com Fixes: bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Mel Gorman <mgorman <mgorman@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26zsmalloc: introduce SG-list based object read APISergey Senozhatsky
Currently, zsmalloc performs address linearization on read (which sometimes requires memcpy() to a local buffer). Not all zsmalloc users need a linear address. For example, Crypto API supports SG-list, performing linearization under the hood, if needed. In addition, some compressors can have native SG-list support, completely avoiding the linearization step. Provide an SG-list based zsmalloc read API: - zs_obj_read_sg_begin() - zs_obj_read_sg_end() This API allows callers to obtain an SG representation of the object (one entry for objects that are contained in a single page and two entries for spanning objects), avoiding the need for a bounce buffer and memcpy. [senozhatsky@chromium.org: make zs_obj_read_sg_begin() return void, per Yosry] Link: https://lkml.kernel.org/r/20260117024900.792237-1-senozhatsky@chromium.org Link: https://lkml.kernel.org/r/20260113034645.2729998-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Yosry Ahmed <yosry.ahmed@linux.dev> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Brian Geffon <bgeffon@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: kmsan: add test_uninit_pageAlexander Potapenko
Test that pages allocated with alloc_page() are uninitialized by default. Link: https://lkml.kernel.org/r/20260113091151.4035013-2-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: kmsan: add tests for high-order page freeingAlexander Potapenko
Add regression tests to verify that KMSAN correctly poisons the full memory range when freeing pages. Specifically, verify that accessing the tail pages of a high-order non-compound allocation triggers a use-after-free report. This ensures that the fix "mm: kmsan: Fix poisoning of high-order non-compound pages" is working as expected. Also add a test for standard order-0 pages for completeness. Link: https://lore.kernel.org/all/20260104134348.3544298-1-ryan.roberts@arm.com/ Link: https://lkml.kernel.org/r/20260113091151.4035013-1-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/lru_sort: add monitoring intervals auto-tuning parameterSeongJae Park
DAMON monitoring intervals tuning was crucial for every DAMON use case. Now there are a tuning guideline and an automated intervals tuning feature. DAMON_LRU_SORT is still using manual control of intervals. Add a module parameter for utilizing the auto-tuning feature with a suggested auto-tuning parameters. Link: https://lkml.kernel.org/r/20260113152717.70459-11-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: wang lian <lianux.mm@gmail.com> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/lru_sort: support active:inactive memory ratio based auto-tuningSeongJae Park
Doing DAMOS_LRU_[DE]PRIO with DAMOS_QUOTA_[IN]ACTIVE_MEM_BP based quota auto-tuning can be easy and intuitive, compared to the manual [de]prioritization target access pattern thresholds tuning. For example, users can ask DAMON to "find hot/cold pages and activate/deactivate those aiming 50:50 active:inactive memory size." But DAMON_LRU_SORT has no interface to do that. Add a module parameter for setting the target ratio. [sj@kernel.org: add inactive mem ratio quota goal to cold_scheme] Link: https://lkml.kernel.org/r/20260114055308.79884-1-sj@kernel.org Link: https://lkml.kernel.org/r/20260113152717.70459-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/lru_sort: support young page filtersSeongJae Park
DAMON monitors access patterns at the region level, and hence there could be some page level mismatches. A few hot pages could be located in cold regions, and vice versa. Young page filters can be useful for doing additional page level access checks before applying some DAMOS action. DAMON_LRU_SORT is not using young page filters, though. Add a parameter for using it. Link: https://lkml.kernel.org/r/20260113152717.70459-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/lru_sort: consider age for quota prioritizationSeongJae Park
DAMON_LRU_SORT is doing under-quota access pattern based regions prioritization using only access frequency. Age of regions is another useful information for distinguishing hot and cold regions. Use it for prioritization, too. Link: https://lkml.kernel.org/r/20260113152717.70459-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/paddr: activate DAMOS_LRU_PRIO targets instead of marking accessedSeongJae Park
DAMOS_LRU_DEPRIOD directly deactivates the pages, while DAMOS_LRU_PRIO calls folio_mark_accessed(), which does incremental activation. The incremental activation was assumed to be useful for making sure the pages of the hot memory region are really hot. After the introduction of DAMOS_LRU_PRIO, the young page filter has added. Users can use the young page filter to make sure the page is eligible to be activated. Meanwhile, the asymmetric behavior of DAMOS_LRU_[DE]PRIO can confuse users. Directly activate given pages for DAMOS_LRU_PRIO, to eliminate the unnecessary incremental activation steps, and be symmetric with DAMOS_LRU_DEPRIO for easier usages. Link: https://lkml.kernel.org/r/20260113152717.70459-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/sysfs-schemes: support DAMOS_QUOTA_[IN]ACTIVE_MEM_BPSeongJae Park
Add support of DAMOS_QUOTA_[IN]ACTIVE_MEM_BP on DAMON sysfs interface. Users can use [in]active_mem_bp keyword input to the target_metric sysfs file to use the new DAMOS quota auto-tune target metrics. Link: https://lkml.kernel.org/r/20260113152717.70459-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: wang lian <lianux.mm@gmail.com> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/core: introduce [in]active memory ratio damos quota goal metricSeongJae Park
Patch series "mm/damon: advance DAMOS-based LRU sorting". DAMOS_LRU_[DE]PRIO actions were added to DAMOS for more access-aware LRU lists sorting. For simple usage, a specialized kernel module, namely DAMON_LRU_SORT, has also been introduced. After the introduction of the module, DAMON got a few important new features, including the aim-based quota auto-tuning, age tracking, young page filter, and monitoring intervals auto-tuning. Meanwhile, DAMOS-based LRU sorting had no direct updates. Now we show some rooms to advance for DAMOS-based LRU sorting. Firstly, the aim-oriented quota auto-tuning can simplify the LRU sorting parameters tuning. But there is no good auto-tuning target metric for LRU sorting use case. Secondly, the behavior of DAMOS_LRU_[DE]PRIO are not very symmetric. DAMOS_LRU_DEPRIO directly moves the pages to inactive LRU list, while DAMOS_LRU_PRIO only marks the page as accessed, so that the page can not directly but only eventually moved to the active LRU list. Finally, DAMON_LRU_SORT users cannot utilize the modern features that can be useful for them, too. Improve the situation with the following changes. First, introduce a new DAMOS quota auto-tuning target metric for active:inactive memory size ratio. Since LRU sorting is a kind of balancing of active and inactive pages, the active:inactive memory size ratio can be intuitively set. Second, update DAMOS_LRU_[DE]PRIO behaviors to be more intuitive and symmetric, by letting them directly move the pages to [in]active LRU list. Third, update the DAMON_LRU_SORT module user interface to be able to fully utilize the modern features including the [in]active memory size ratio-based quota auto-tuning, young page filter, and monitoring intervals auto-tuning. With these changes, for example, users can now ask DAMON to "find hot/cold memory regions with auto-tuned monitoring intervals, do one more page level access check for found hot/cold memory, and move pages of those to active or inactive LRU lists accordingly, aiming X:Y active to inactive memory ratio." For example, if they know 30% of the memory is better to be protected from reclamation, 30:70 can be set as the target ratio. Test Results ------------ I ran DAMON_LRU_SORT with the features introduced by this series, on a real world server workload. For the active:inactive ratio goal, I set 50:50. I confirmed it achieves the target active:inactive ratio, without manual tuning of the monitoring intervals and the hot/coldness thresholds. The baseline system that was not running the DAMON_LRU_SORT was keeping active:inactive ratio of about 1:10. Note that the test didn't show a clear performance difference, though. I believe that was mainly because the workload was not very memory intensive. Also, whether the 50:50 target ratio was optimum is unclear. Nonetheless, the positive performance impact of the basic LRU sorting idea is already confirmed with the initial DAMON_LRU_SORT introduction patch series. The goal of this patch series is simplifying the parameters tuning of DAMOS-based LRU sorting, and the test confirmed the aimed goals are achieved. Patches Sequence ---------------- First three patches extend DAMOS quota auto-tuning to support [in]active memory ratio target metric type. Those (patches 1-3) introduce new metrics, implement DAMON sysfs support, and update the documentation, respectively. Following patch (patch 4) makes DAMOS_LRU_PRIO action to directly move target pages to active LRU list, instead of only marking them accessed. Following seven patches (patches 5-11) updates DAMON_LRU_SORT to support modern DAMON features. Patch 5 makes it uses not only access frequency but also age at under-quota regions prioritization. Patches 6-11 add the support for young page filtering, active:inactive memory ratio based quota auto-tuning, and monitoring intervals auto-tuning, with appropriate document updates. This patch (of 11): DAMOS_LRU_[DE]PRIO are DAMOS actions for making balance of active and inactive memory size. There is no appropriate DAMOS quota auto-tuning target metric for the use case. Add two new DAMOS quota goal metrics for the purpose, namely DAMOS_QUOTA_[IN]ACTIVE_MEM_BP. Those will represent the ratio of [in]active memory to total (inactive + active) memory. Hence, users will be able to ask DAMON to, for example, "find hot and cold memory, and move pages of those to active and inactive LRU lists, adjusting the hot/cold thresholds aiming 50:50 active:inactive memory ratio." Link: https://lkml.kernel.org/r/20260113152717.70459-1-sj@kernel.org Link: https://lkml.kernel.org/r/20260113152717.70459-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/kasan/kunit: extend vmalloc OOB tests to cover vrealloc()Andrey Ryabinin
Extend the vmalloc_oob() test to validate OOB detection after resizing vmalloc allocations with vrealloc(). The test now verifies that KASAN correctly poisons and unpoisons vmalloc memory when allocations are shrunk and expanded, ensuring OOB accesses are reliably detected after each resize. [ryabinin.a.a@gmail.com: adjust vrealloc() size] Link: https://lkml.kernel.org/r/20260116132822.22227-1-ryabinin.a.a@gmail.com Link: https://lkml.kernel.org/r/20260113191516.31015-2-ryabinin.a.a@gmail.com Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26vmalloc: export vrealloc_node_align_noprofAlice Ryhl
This symbol is used from the Nova driver, so it needs to be exported to avoid a build failure when building Nova as a module. ERROR: modpost: "vrealloc_node_align_noprof" [drivers/gpu/nova-core/nova_core.ko] undefined! ERROR: modpost: "vrealloc_node_align_noprof" [samples/rust/rust_dma.ko] undefined! This error is only triggered if helpers are inlined into Rust. Otherwise, Nova will call the exported symbol rust_helper_vrealloc_node_align() instead. There is no Fixes: tag as that feature is still WIP. I used non-GPL EXPORT_SYMBOL to match the rest of the file, but let me know if I should use EXPORT_SYMBOL_GPL. Link: https://lkml.kernel.org/r/20260107-export-vrealloc_node_align_noprof-v1-1-a581bec13054@google.com Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Danilo Krummrich <dakr@kernel.org> Cc: Andreas Hindborg <a.hindborg@kernel.org> Cc: Björn Roy Baron <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Gary Guo <gary@garyguo.net> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Trevor Gross <tmgross@umich.edu> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: hugetlb: allocate frozen pages for gigantic allocationKefeng Wang
alloc_gigantic_folio() allocates a folio with refcount increated and then freeze it, convert to allocate a frozen folio to remove the atomic operation about folio refcount, and saving atomic operation during __update_and_free_hugetlb_folio() too. Besides, rename hugetlb_cma_{alloc,free}_folio(), alloc_gigantic_folio() and alloc_buddy_hugetlb_folio() with frozen which make them more self-explanatory. Link: https://lkml.kernel.org/r/20260109093136.1491549-7-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Cc: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: cma: add cma_alloc_frozen{_compound}()Kefeng Wang
Introduce cma_alloc_frozen{_compound}() helper to alloc pages without incrementing their refcount, then convert hugetlb cma to use the cma_alloc_frozen_compound() and cma_release_frozen() and remove the unused cma_{alloc,free}_folio(), also move the cma_validate_zones() into mm/internal.h since no outside user. The set_pages_refcounted() is only called to set non-compound pages after above changes, so remove the processing about PageHead. Link: https://lkml.kernel.org/r/20260109093136.1491549-6-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: page_alloc: add alloc_contig_frozen_{range,pages}()Kefeng Wang
In order to allocate given range of pages or allocate compound pages without incrementing their refcount, adding two new helper alloc_contig_frozen_{range,pages}() which may be beneficial to some users (eg hugetlb). The new alloc_contig_{range,pages} only take !__GFP_COMP gfp now, and the free_contig_range() is refactored to only free non-compound pages, the only caller to free compound pages in cma_free_folio() is changed accordingly, and the free_contig_frozen_range() is provided to match the alloc_contig_frozen_range(), which is used to free frozen pages. Link: https://lkml.kernel.org/r/20260109093136.1491549-5-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: cma: kill cma_pages_valid()Kefeng Wang
Kill cma_pages_valid() which only used in cma_release(), also cleanup code duplication between cma pages valid checking and cma memrange finding. Link: https://lkml.kernel.org/r/20260109093136.1491549-4-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: page_alloc: add __split_page()Kefeng Wang
Factor out the splitting of non-compound page from make_alloc_exact() and split_page() into a new helper function __split_page(). While at it, convert the VM_BUG_ON_PAGE() into a VM_WARN_ON_PAGE(). Link: https://lkml.kernel.org/r/20260109093136.1491549-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Muchun Song <muchun.song@linux.dev> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm: debug_vm_pgtable: add debug_vm_pgtable_free_huge_page()Kefeng Wang
Patch series "mm: hugetlb: allocate frozen gigantic folio", v6. Introduce alloc_contig_frozen_pages() and cma_alloc_frozen_compound() which avoid atomic operation about page refcount, and then convert to allocate frozen gigantic folio by the new helpers in hugetlb to cleanup the alloc_gigantic_folio(). This patch (of 6): Add a new helper to free huge page to be consistency to debug_vm_pgtable_alloc_huge_page(), and use HPAGE_PUD_ORDER instead of open-code. Also move the free_contig_range() under CONFIG_ALLOC_CONTIG since all caller are built with CONFIG_ALLOC_CONTIG. Link: https://lkml.kernel.org/r/20260109093136.1491549-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_nodeDeepanshu Kartikey
When CONFIG_PAGE_OWNER is enabled, freeing KASAN shadow pages during vmalloc cleanup triggers expensive stack unwinding that acquires RCU read locks. Processing a large purge_list without rescheduling can cause the task to hold CPU for extended periods (10+ seconds), leading to RCU stalls and potential OOM conditions. The issue manifests in purge_vmap_node() -> kasan_release_vmalloc_node() where iterating through hundreds or thousands of vmap_area entries and freeing their associated shadow pages causes: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6229/1:b..l ... task:kworker/0:17 state:R running task stack:28840 pid:6229 ... kasan_release_vmalloc_node+0x1ba/0xad0 mm/vmalloc.c:2299 purge_vmap_node+0x1ba/0xad0 mm/vmalloc.c:2299 Each call to kasan_release_vmalloc() can free many pages, and with page_owner tracking, each free triggers save_stack() which performs stack unwinding under RCU read lock. Without yielding, this creates an unbounded RCU critical section. Add periodic cond_resched() calls within the loop to allow: - RCU grace periods to complete - Other tasks to run - Scheduler to preempt when needed The fix uses need_resched() for immediate response under load, with a batch count of 32 as a guaranteed upper bound to prevent worst-case stalls even under light load. Link: https://lkml.kernel.org/r/20260112103612.627247-1-kartikey406@gmail.com Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Reported-by: syzbot+d8d4c31d40f868eaea30@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d8d4c31d40f868eaea30 Link: https://lore.kernel.org/all/20260112084723.622910-1-kartikey406@gmail.com/T/ [v1] Suggested-by: Uladzislau Rezki <urezki@gmail.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/early_ioremap: clean up the use of WARN() for debuggingHou Wenlong
Using WARN() for debugging is strange when nothing is wrong, so replace WARN(early_ioremap_debug) with pr_warn() + dump_stack(). Link: https://lkml.kernel.org/r/d4470531ce0c03fd80f9a1be7e8d8ae1bc60fcd1.1768220636.git.houwenlong.hwl@antgroup.com Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com> Suggested-by: Mike Rapoport <rppt@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Hou Wenlong <houwenlong.hwl@antgroup.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/early_ioremap: print the starting physical address in __early_ioremap()Hou Wenlong
The debug WARN() printing occurs after the while loop, so the 'phys_addr' reflects the last physical address rather than the actual starting physical address, which is not useful for debugging. To simplify, the WARN() statement could be moved up before the loop instead of introducing a new variable to record the original 'phys_addr' value. Additionally, swap the print order of 'slot_virt[slot]' and 'offset', as this will enhance output readability. Link: https://lkml.kernel.org/r/aa2d44c34f44c31b50285b7592ed4fd78d6f59ba.1767965415.git.houwenlong.hwl@antgroup.com Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon/paddr: initialize 'folio' variables to NULL for clarityAaron Yang
In damon_pa_mark_accessed_or_deactivate(), damon_pa_pageout(), damon_pa_migrate(), and damon_pa_stat(), the local variable 'folio' is declared but not initialized. Initialize 'folio' to NULL to improve code readability and maintainability. Link: https://patch.msgid.link/20260104013255.16962-1-yangqixiao@inspur.com Link: https://lkml.kernel.org/r/20260108013041.80601-1-sj@kernel.org Signed-off-by: Aaron Yang <yangqixiao@inspur.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26zsmalloc: simplify read begin/end logicYosry Ahmed
zs_obj_read_begin() currently maps or copies the compressed object with the prefix handle for !ZsHugePage case. Make the logic clearer and more efficient by moving the offset of the object in the page after the prefix handle instead, only copying the actual object and avoiding the need to adjust the returned address to account for the prefix. Adjust the logic to detect spanning objects in zs_obj_read_end() accordingly, slightly simplifying it by avoiding the need to account for the handle in both the offset and the object size. Link: https://lkml.kernel.org/r/20260107052145.3586917-2-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Co-developed-by: Yosry Ahmed <yosry.ahmed@linux.dev> Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev> Cc: Brian Geffon <bgeffon@google.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26zsmalloc: use actual object size to detect spansSergey Senozhatsky
Using class->size to detect spanning objects is not entirely correct, because some size classes can hold a range of object sizes of up to class->size bytes in length, due to size-classes merge. Such classes use padding for cases when actually written objects are smaller than class->size. zs_obj_read_begin() can incorrectly hit the slow path and perform memcpy of such objects, basically copying padding bytes. Instead of class->size zs_obj_read_begin() should use the actual compressed object length (both zram and zswap know it) so that it can correctly handle situations when a written object is small enough to fit into the first physical page. Link: https://lkml.kernel.org/r/20260107052145.3586917-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev> [zsmalloc & zswap] Reviewed-by: Nhat Pham <nphamcs@gmail.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26memcg: rename mem_cgroup_ino() to mem_cgroup_id()Shakeel Butt
Rename mem_cgroup_ino() to mem_cgroup_id() and mem_cgroup_get_from_ino() to mem_cgroup_get_from_id(). These functions now use cgroup IDs (from cgroup_id()) rather than inode numbers, so the names should reflect that. [shakeel.butt@linux.dev: replace ino with id, per SeongJae] Link: https://lkml.kernel.org/r/flkqanhyettp5uq22bjwg37rtmnpeg3mghznsylxcxxgaafpl4@nov2x7tagma7 [akpm@linux-foundation.org: build fix] Link: https://lkml.kernel.org/r/20251225232116.294540-9-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: David Hildenbrand <david@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26memcg: remove unused mem_cgroup_id() and mem_cgroup_from_id()Shakeel Butt
Now that all callers have been converted to use either: - The private ID APIs (mem_cgroup_private_id/mem_cgroup_from_private_id) for internal kernel objects that outlive their cgroup - The public cgroup ID APIs (mem_cgroup_ino/mem_cgroup_get_from_ino) for external interfaces Remove the unused wrapper functions mem_cgroup_id() and mem_cgroup_from_id() along with their !CONFIG_MEMCG stubs. Link: https://lkml.kernel.org/r/20251225232116.294540-8-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: David Hildenbrand <david@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/vmscan: use cgroup ID instead of private memcg ID in lru_gen interfaceShakeel Butt
The LRU gen debugfs interface was using the internal private memcg ID which is meant for tracking kernel objects that outlive their cgroup. Switch to using the public cgroup ID instead. Link: https://lkml.kernel.org/r/20251225232116.294540-7-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: David Hildenbrand <david@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26mm/damon: use cgroup ID instead of private memcg IDShakeel Butt
DAMON was using the internal private memcg ID which is meant for tracking kernel objects that outlive their cgroup. Switch to using the public cgroup ID instead. Link: https://lkml.kernel.org/r/20251225232116.294540-6-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: SeongJae Park <sj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: David Hildenbrand <david@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26memcg: use cgroup_id() instead of cgroup_ino() for memcg IDShakeel Butt
Switch mem_cgroup_ino() from using cgroup_ino() to cgroup_id(). The cgroup_ino() returns the kernfs inode number while cgroup_id() returns the kernfs node ID. For 64-bit systems, they are the same. Also cgroup_get_from_id() expects 64-bit node ID which is called by mem_cgroup_get_from_ino(). Change the type from unsigned long to u64 to match cgroup_id()'s return type, and update the format specifiers accordingly. Note that the names mem_cgroup_ino() and mem_cgroup_get_from_ino() are now misnomers since they deal with cgroup IDs rather than inode numbers. A follow-up patch will rename them. Link: https://lkml.kernel.org/r/20251225232116.294540-5-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: David Hildenbrand <david@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26memcg: mem_cgroup_get_from_ino() returns NULL on errorShakeel Butt
Change mem_cgroup_get_from_ino() to return NULL on error instead of ERR_PTR values. This simplifies the API: NULL indicates failure, and a valid pointer indicates success with a CSS reference held that the caller must release via mem_cgroup_put(). Link: https://lkml.kernel.org/r/20251225232116.294540-4-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: David Hildenbrand <david@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>