linux-stable.git/drivers/tty/sysrq.c, branch linux-4.8.y

mm: oom: add memcg to oom_control

2016-07-26T23:19:19+00:00

It's a part of oom context just like allocation order and nodemask, so
let's move it to oom_control instead of passing it in the argument list.

Link: http://lkml.kernel.org/r/40e03fd7aaf1f55c75d787128d6d17c5a71226c2.1464358556.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov 
Acked-by: Michal Hocko 
Acked-by: Johannes Weiner 
Cc: Tetsuo Handa 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysrq: Fix warning in sysrq generated crash.

2015-12-30T00:29:18+00:00

Commit 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") replaced
spin_lock_irqsave() calls with rcu_read_lock() calls in sysrq. Since
rcu_read_lock() does not disable preemption, faulthandler_disabled() in
__do_page_fault() in x86/fault.c returns false. When the code later calls
might_sleep() in the pagefault handler, we get the following warning:

BUG: sleeping function called from invalid context at ../arch/x86/mm/fault.c:1187
in_atomic(): 0, irqs_disabled(): 0, pid: 4706, name: bash
Preemption disabled at:[] printk+0x48/0x4a

To fix this, we release the RCU read lock before we crash.

Tested this patch on linux 3.18 by booting off one of our boards.

Fixes: 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq")

Signed-off-by: Ani Sinha 
Reviewed-by: Rik van Riel 
Signed-off-by: Paul E. McKenney

drivers/tty: make sysrq.c slightly more explicitly non-modular

2015-10-04T16:27:56+00:00

The Kconfig currently controlling compilation of this code is:

config.debug:config MAGIC_SYSRQ
      bool "Magic SysRq key"

...meaning that it currently is not being built as a module by anyone.

Lets remove the traces of modularity we can so that when reading the
driver there is less doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't delete the module.h include since other parts of the file are
using content from there.

Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Signed-off-by: Paul Gortmaker 
Signed-off-by: Greg Kroah-Hartman

mm, oom: pass an oom order of -1 when triggered by sysrq

2015-09-08T22:35:28+00:00

The force_kill member of struct oom_control isn't needed if an order of -1
is used instead.  This is the same as order == -1 in struct
compact_control which requires full memory compaction.

This patch introduces no functional change.

Signed-off-by: David Rientjes 
Cc: Sergey Senozhatsky 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, oom: organize oom context into struct

2015-09-08T22:35:28+00:00

There are essential elements to an oom context that are passed around to
multiple functions.

Organize these elements into a new struct, struct oom_control, that
specifies the context for an oom condition.

This patch introduces no functional change.

Signed-off-by: David Rientjes 
Acked-by: Michal Hocko 
Cc: Sergey Senozhatsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-07-01T17:49:25+00:00

Pull module updates from Rusty Russell:
 "Main excitement here is Peter Zijlstra's lockless rbtree optimization
  to speed module address lookup.  He found some abusers of the module
  lock doing that too.

  A little bit of parameter work here too; including Dan Streetman's
  breaking up the big param mutex so writing a parameter can load
  another module (yeah, really).  Unfortunately that broke the usual
  suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were
  appended too"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits)
  modules: only use mod->param_lock if CONFIG_MODULES
  param: fix module param locks when !CONFIG_SYSFS.
  rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()
  module: add per-module param_lock
  module: make perm const
  params: suppress unused variable error, warn once just in case code changes.
  modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.
  kernel/module.c: avoid ifdefs for sig_enforce declaration
  kernel/workqueue.c: remove ifdefs over wq_power_efficient
  kernel/params.c: export param_ops_bool_enable_only
  kernel/params.c: generalize bool_enable_only
  kernel/module.c: use generic module param operaters for sig_enforce
  kernel/params: constify struct kernel_param_ops uses
  sysfs: tightened sysfs permission checks
  module: Rework module_addr_{min,max}
  module: Use __module_address() for module_address_lookup()
  module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING
  module: Optimize __module_address() using a latched RB-tree
  rbtree: Implement generic latch_tree
  seqlock: Introduce raw_read_seqcount_latch()
  ...

Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

2015-06-27T19:44:34+00:00

Pull MIPS updates from Ralf Baechle:

 - Improvements to the tlb_dump code
 - KVM fixes
 - Add support for appended DTB
 - Minor improvements to the R12000 support
 - Minor improvements to the R12000 support
 - Various platform improvments for BCM47xx
 - The usual pile of minor cleanups
 - A number of BPF fixes and improvments
 - Some improvments to the support for R3000 and DECstations
 - Some improvments to the ATH79 platform support
 - A major patchset for the JZ4740 SOC adding support for the CI20 platform
 - Add support for the Pistachio SOC
 - Minor BMIPS/BCM63xx platform support improvments.
 - Avoid "SYNC 0" as memory barrier when unlocking spinlocks
 - Add support for the XWR-1750 board.
 - Paul's __cpuinit/__cpuinitdata cleanups.
 - New Malta CPU board support large memory so enable ZONE_DMA32.

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (131 commits)
  MIPS: spinlock: Adjust arch_spin_lock back-off time
  MIPS: asmmacro: Ensure 64-bit FP registers are used with MSA
  MIPS: BCM47xx: Simplify handling SPROM revisions
  MIPS: Cobalt Don't use module_init in non-modular MTD registration.
  MIPS: BCM47xx: Move NVRAM driver to the drivers/firmware/
  MIPS: use for_each_sg()
  MIPS: BCM47xx: Don't select BCMA_HOST_PCI
  MIPS: BCM47xx: Add helper variable for storing NVRAM length
  MIPS: IRQ/IP27: Move IRQ allocation API to platform code.
  MIPS: Replace smp_mb with release barrier function in unlocks.
  MIPS: i8259: DT support
  MIPS: Malta: Basic DT plumbing
  MIPS: include errno.h for ENODEV in mips-cm.h
  MIPS: Define GCR_GIC_STATUS register fields
  MIPS: BPF: Introduce BPF ASM helpers
  MIPS: BPF: Use BPF register names to describe the ABI
  MIPS: BPF: Move register definition to the BPF header
  MIPS: net: BPF: Replace RSIZE with SZREG
  MIPS: BPF: Free up some callee-saved registers
  MIPS: Xtalk: Update xwidget.h with known Xtalk device numbers
  ...

Merge branch 'akpm' (patches from Andrew)

2015-06-25T03:47:21+00:00

Merge first patchbomb from Andrew Morton:

 - a few misc things

 - ocfs2 udpates

 - kernel/watchdog.c feature work (took ages to get right)

 - most of MM.  A few tricky bits are held up and probably won't make 4.2.

* emailed patches from Andrew Morton : (91 commits)
  mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc()
  mm, thp: respect MPOL_PREFERRED policy with non-local node
  tmpfs: truncate prealloc blocks past i_size
  mm/memory hotplug: print the last vmemmap region at the end of hot add memory
  mm/mmap.c: optimization of do_mmap_pgoff function
  mm: kmemleak: optimise kmemleak_lock acquiring during kmemleak_scan
  mm: kmemleak: avoid deadlock on the kmemleak object insertion error path
  mm: kmemleak: do not acquire scan_mutex in kmemleak_do_cleanup()
  mm: kmemleak: fix delete_object_*() race when called on the same memory block
  mm: kmemleak: allow safe memory scanning during kmemleak disabling
  memcg: convert mem_cgroup->under_oom from atomic_t to int
  memcg: remove unused mem_cgroup->oom_wakeups
  frontswap: allow multiple backends
  x86, mirror: x86 enabling - find mirrored memory ranges
  mm/memblock: allocate boot time data structures from mirrored memory
  mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute
  mm: do not ignore mapping_gfp_mask in page cache allocation paths
  mm/cma.c: fix typos in comments
  mm/oom_kill.c: print points as unsigned int
  mm/hugetlb: handle races in alloc_huge_page and hugetlb_reserve_pages
  ...

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

2015-06-25T02:56:58+00:00

Pull input subsystem updates from Dmitry Torokhov:
 "Thanks to Samuel Thibault input device (keyboard) LEDs are no longer
  hardwired within the input core but use LED subsystem and so allow use
  of different triggers; Hans de Goede did a large update for the ALPS
  touchpad driver; we have new TI drv2665 haptics driver and DA9063
  OnKey driver, and host of other drivers got various fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (55 commits)
  Input: pixcir_i2c_ts - fix receive error
  MAINTAINERS: remove non existent input mt git tree
  Input: improve usage of gpiod API
  tty/vt/keyboard: define LED triggers for VT keyboard lock states
  tty/vt/keyboard: define LED triggers for VT LED states
  Input: export LEDs as class devices in sysfs
  Input: cyttsp4 - use swap() in cyttsp4_get_touch()
  Input: goodix - do not explicitly set evbits in input device
  Input: goodix - export id and version read from device
  Input: goodix - fix variable length array warning
  Input: goodix - fix alignment issues
  Input: add OnKey driver for DA9063 MFD part
  Input: elan_i2c - add product IDs FW names
  Input: elan_i2c - add support for multi IC type and iap format
  Input: focaltech - report finger width to userspace
  tty: remove platform_sysrq_reset_seq
  Input: synaptics_i2c - use proper boolean values
  Input: psmouse - use true instead of 1 for boolean values
  Input: cyapa - fix a few typos in comments
  Input: stmpe-ts - enforce device tree only mode
  ...

mm: oom_kill: simplify OOM killer locking

2015-06-25T00:49:43+00:00

The zonelist locking and the oom_sem are two overlapping locks that are
used to serialize global OOM killing against different things.

The historical zonelist locking serializes OOM kills from allocations with
overlapping zonelists against each other to prevent killing more tasks
than necessary in the same memory domain.  Only when neither tasklists nor
zonelists from two concurrent OOM kills overlap (tasks in separate memcgs
bound to separate nodes) are OOM kills allowed to execute in parallel.

The younger oom_sem is a read-write lock to serialize OOM killing against
the PM code trying to disable the OOM killer altogether.

However, the OOM killer is a fairly cold error path, there is really no
reason to optimize for highly performant and concurrent OOM kills.  And
the oom_sem is just flat-out redundant.

Replace both locking schemes with a single global mutex serializing OOM
kills regardless of context.

Signed-off-by: Johannes Weiner 
Acked-by: Michal Hocko 
Acked-by: David Rientjes 
Cc: Tetsuo Handa 
Cc: Andrea Arcangeli 
Cc: Dave Chinner 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds