The patch titled
oom: remove unnecessary code and cleanup
has been added to the -mm tree. Its filename is
oom-remove-unnecessary-code-and-cleanup.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: oom: remove unnecessary code and cleanup
From: David Rientjes <rientjes@xxxxxxxxxx>
Remove the redundancy in __oom_kill_task() since:
- init can never be passed to this function: it will never be PF_EXITING
or selectable from select_bad_process(), and
- it will never be passed a task from oom_kill_task() without an ->mm
and we're unconcerned about detachment from exiting tasks, there's no
reason to protect them against SIGKILL or access to memory reserves.
Also moves the kernel log message to a higher level since the verbosity is
not always emitted here; we need not print an error message if an exiting
task is given a longer timeslice.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/oom_kill.c | 64 ++++++++++++------------------------------------
1 file changed, 16 insertions(+), 48 deletions(-)
diff -puN mm/oom_kill.c~oom-remove-unnecessary-code-and-cleanup mm/oom_kill.c
--- a/mm/oom_kill.c~oom-remove-unnecessary-code-and-cleanup
+++ a/mm/oom_kill.c
@@ -412,67 +412,35 @@ static void dump_header(struct task_stru
dump_tasks(mem);
}
-#define K(x) ((x) << (PAGE_SHIFT-10))
-
/*
- * Send SIGKILL to the selected process irrespective of CAP_SYS_RAW_IO
- * flag though it's unlikely that we select a process with CAP_SYS_RAW_IO
- * set.
+ * Give the oom killed task high priority and access to memory reserves so that
+ * it may quickly exit and free its memory.
*/
-static void __oom_kill_task(struct task_struct *p, int verbose)
+static void __oom_kill_task(struct task_struct *p)
{
- if (is_global_init(p)) {
- WARN_ON(1);
- printk(KERN_WARNING "tried to kill init!\n");
- return;
- }
-
- task_lock(p);
- if (!p->mm) {
- WARN_ON(1);
- printk(KERN_WARNING "tried to kill an mm-less task %d (%s)!\n",
- task_pid_nr(p), p->comm);
- task_unlock(p);
- return;
- }
-
- if (verbose)
- printk(KERN_ERR "Killed process %d (%s) "
- "vsz:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
- task_pid_nr(p), p->comm,
- K(p->mm->total_vm),
- K(get_mm_counter(p->mm, MM_ANONPAGES)),
- K(get_mm_counter(p->mm, MM_FILEPAGES)));
- task_unlock(p);
-
- /*
- * We give our sacrificial lamb high priority and access to
- * all the memory it needs. That way it should be able to
- * exit() and clear out its resources quickly...
- */
p->rt.time_slice = HZ;
set_tsk_thread_flag(p, TIF_MEMDIE);
-
force_sig(SIGKILL, p);
}
+#define K(x) ((x) << (PAGE_SHIFT-10))
static int oom_kill_task(struct task_struct *p)
{
- /* WARNING: mm may not be dereferenced since we did not obtain its
- * value from get_task_mm(p). This is OK since all we need to do is
- * compare mm to q->mm below.
- *
- * Furthermore, even if mm contains a non-NULL value, p->mm may
- * change to NULL at any time since we do not hold task_lock(p).
- * However, this is of no concern to us.
- */
- if (!p->mm || p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+ task_lock(p);
+ if (!p->mm || p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
+ task_unlock(p);
return 1;
+ }
+ pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
+ task_pid_nr(p), p->comm, K(p->mm->total_vm),
+ K(get_mm_counter(p->mm, MM_ANONPAGES)),
+ K(get_mm_counter(p->mm, MM_FILEPAGES)));
+ task_unlock(p);
- __oom_kill_task(p, 1);
-
+ __oom_kill_task(p);
return 0;
}
+#undef K
static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
unsigned int points, unsigned long totalpages,
@@ -491,7 +459,7 @@ static int oom_kill_process(struct task_
* its children or threads, just set TIF_MEMDIE so it can die quickly
*/
if (p->flags & PF_EXITING) {
- __oom_kill_task(p, 0);
+ __oom_kill_task(p);
return 0;
}
_
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
linux-next.patch
cpuset-fix-the-problem-that-cpuset_mem_spread_node-returns-an-offline-node.patch
cpuset-alloc-nodemask_t-on-the-heap-rather-than-the-stack.patch
mempolicy-remove-redundant-code.patch
oom-filter-tasks-not-sharing-the-same-cpuset.patch
oom-sacrifice-child-with-highest-badness-score-for-parent.patch
oom-select-task-from-tasklist-for-mempolicy-ooms.patch
oom-remove-special-handling-for-pagefault-ooms.patch
oom-badness-heuristic-rewrite.patch
oom-deprecate-oom_adj-tunable.patch
oom-replace-sysctls-with-quick-mode.patch
oom-avoid-oom-killer-for-lowmem-allocations.patch
oom-remove-unnecessary-code-and-cleanup.patch
oom-default-to-killing-current-for-pagefault-ooms.patch
oom-avoid-race-for-oom-killed-tasks-detaching-mm-prior-to-exit.patch
memcg-oom-wakeup-filter.patch
memcg-oom-wakeup-filter-update.patch
memcg-oom-notifier.patch
memcg-oom-notifier-update.patch
memcg-oom-kill-disable-and-oom-status.patch
memcg-oom-kill-disable-and-oom-status-update.patch
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