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  1. 24 9月, 2009 1 次提交
  3. 23 9月, 2009 17 次提交
  5. 22 9月, 2009 8 次提交
  7. 19 8月, 2009 1 次提交
    • K
      mm: revert "oom: move oom_adj value" · 0753ba01
      由 KOSAKI Motohiro 提交于 
      The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to
the mm_struct.  It was a very good first step for sanitize OOM.

However Paul Menage reported the commit makes regression to his job
scheduler.  Current OOM logic can kill OOM_DISABLED process.

Why? His program has the code of similar to the following.

	...
	set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */
	...
	if (vfork() == 0) {
		set_oom_adj(0); /* Invoked child can be killed */
		execve("foo-bar-cmd");
	}
	....

vfork() parent and child are shared the same mm_struct.  then above
set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also
change oom_adj for vfork() parent.  Then, vfork() parent (job scheduler)
lost OOM immune and it was killed.

Actually, fork-setting-exec idiom is very frequently used in userland program.
We must not break this assumption.

Then, this patch revert commit 2ff05b2b and related commit.

Reverted commit list
---------------------
- commit 2ff05b2b (oom: move oom_adj value from task_struct to mm_struct)
- commit 4d8b9135 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE)
- commit 81236810 (oom: only oom kill exiting tasks with attached memory)
- commit 933b787b (mm: copy over oom_adj value at fork time)
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0753ba01
  9. 10 8月, 2009 5 次提交
  11. 24 6月, 2009 1 次提交
    • O
      mm_for_maps: simplify, use ptrace_may_access() · a893a84e
      由 Oleg Nesterov 提交于 
      It would be nice to kill __ptrace_may_access(). It requires task_lock(),
but this lock is only needed to read mm->flags in the middle.

Convert mm_for_maps() to use ptrace_may_access(), this also simplifies
the code a little bit.

Also, we do not need to take ->mmap_sem in advance. In fact I think
mm_for_maps() should not play with ->mmap_sem at all, the caller should
take this lock.

With or without this patch, without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      a893a84e
  13. 19 6月, 2009 3 次提交
  15. 17 6月, 2009 4 次提交
    • D
      oom: move oom_adj value from task_struct to mm_struct · 2ff05b2b
      由 David Rientjes 提交于 
      The per-task oom_adj value is a characteristic of its mm more than the
task itself since it's not possible to oom kill any thread that shares the
mm.  If a task were to be killed while attached to an mm that could not be
freed because another thread were set to OOM_DISABLE, it would have
needlessly been terminated since there is no potential for future memory
freeing.

This patch moves oomkilladj (now more appropriately named oom_adj) from
struct task_struct to struct mm_struct.  This requires task_lock() on a
task to check its oom_adj value to protect against exec, but it's already
necessary to take the lock when dereferencing the mm to find the total VM
size for the badness heuristic.

This fixes a livelock if the oom killer chooses a task and another thread
sharing the same memory has an oom_adj value of OOM_DISABLE.  This occurs
because oom_kill_task() repeatedly returns 1 and refuses to kill the
chosen task while select_bad_process() will repeatedly choose the same
task during the next retry.

Taking task_lock() in select_bad_process() to check for OOM_DISABLE and in
oom_kill_task() to check for threads sharing the same memory will be
removed in the next patch in this series where it will no longer be
necessary.

Writing to /proc/pid/oom_adj for a kthread will now return -EINVAL since
these threads are immune from oom killing already.  They simply report an
oom_adj value of OOM_DISABLE.

Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2ff05b2b
    • K
      mm: remove CONFIG_UNEVICTABLE_LRU config option · 68377659
      由 KOSAKI Motohiro 提交于 
      Currently, nobody wants to turn UNEVICTABLE_LRU off.  Thus this
configurability is unnecessary.
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: NMinchan Kim <minchan.kim@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      68377659
    • W
      proc: export more page flags in /proc/kpageflags · 17797549
      由 Wu Fengguang 提交于 
      Export all page flags faithfully in /proc/kpageflags.

	11. KPF_MMAP		(pseudo flag) memory mapped page
	12. KPF_ANON		(pseudo flag) memory mapped page (anonymous)
	13. KPF_SWAPCACHE	page is in swap cache
	14. KPF_SWAPBACKED	page is swap/RAM backed
	15. KPF_COMPOUND_HEAD	(*)
	16. KPF_COMPOUND_TAIL	(*)
	17. KPF_HUGE		hugeTLB pages
	18. KPF_UNEVICTABLE	page is in the unevictable LRU list
	19. KPF_HWPOISON(TBD)	hardware detected corruption
	20. KPF_NOPAGE		(pseudo flag) no page frame at the address
	32-39.			more obscure flags for kernel developers

	(*) For compound pages, exporting _both_ head/tail info enables
	    users to tell where a compound page starts/ends, and its order.

The accompanying page-types tool will handle the details like decoupling
overloaded flags and hiding obscure flags to normal users.

Thanks to KOSAKI and Andi for their valuable recommendations!
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      17797549
    • W
      proc: kpagecount/kpageflags code cleanup · ed7ce0f1
      由 Wu Fengguang 提交于 
      Move increments of pfn/out to bottom of the loop.
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: NMatt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ed7ce0f1