[PATCH 3/5] oom: Fix child process iteration properly
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From: KOSAKI Motohiro on 1 Jun 2010 01:50 Oleg pointed out that current oom child process iterating logic is wrong. > list_for_each_entry(p->children) can only see the tasks forked > by p, it can't see other children forked by its sub-threads. This patch fixes it. Reported-by: Oleg Nesterov <oleg(a)redhat.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro(a)jp.fujitsu.com> --- mm/oom_kill.c | 34 ++++++++++++++++++++-------------- 1 files changed, 20 insertions(+), 14 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 70e1a85..1bdf27d 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -88,6 +88,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) { unsigned long points, cpu_time, run_time; struct task_struct *c; + struct task_struct *t = p; struct task_struct *child; int oom_adj = p->signal->oom_adj; struct task_cputime task_time; @@ -125,14 +126,16 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) * child is eating the vast majority of memory, adding only half * to the parents will make the child our kill candidate of choice. */ - list_for_each_entry(c, &p->children, sibling) { - child = find_lock_task_mm(c); - if (child) { - if (child->mm != p->mm) - points += child->mm->total_vm/2 + 1; - task_unlock(child); + do { + list_for_each_entry(c, &t->children, sibling) { + child = find_lock_task_mm(c); + if (child) { + if (child->mm != p->mm) + points += child->mm->total_vm/2 + 1; + task_unlock(child); + } } - } + } while_each_thread(p, t); /* * CPU time is in tens of seconds and run time is in thousands @@ -432,6 +435,7 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, const char *message) { struct task_struct *c; + struct task_struct *t = p; if (printk_ratelimit()) dump_header(p, gfp_mask, order, mem); @@ -449,14 +453,16 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, message, task_pid_nr(p), p->comm, points); /* Try to kill a child first */ - list_for_each_entry(c, &p->children, sibling) { - if (c->mm == p->mm) - continue; + do { + list_for_each_entry(c, &t->children, sibling) { + if (c->mm == p->mm) + continue; - /* Ok, Kill the child */ - if (!__oom_kill_process(c, mem, 1)) - return 0; - } + /* Ok, Kill the child */ + if (!__oom_kill_process(c, mem, 1)) + return 0; + } + } while_each_thread(p, t); return __oom_kill_process(p, mem, 1); } -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |