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authorOleg Nesterov <oleg@tv-sign.ru>2008-07-25 04:47:44 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 13:53:40 -0400
commitb564daf806d492dd4f7afe9b6c83b8d35d137669 (patch)
treefbd6d186035b9a0a270fca97887da5d6b106a60c /kernel/exit.c
parent9d5b327bf198d2720666de958dcc2ae219d86952 (diff)
coredump: construct the list of coredumping threads at startup time
binfmt->core_dump() has to iterate over the all threads in system in order to find the coredumping threads and construct the list using the GFP_ATOMIC allocations. With this patch each thread allocates the list node on exit_mm()'s stack and adds itself to the list. This allows us to do further changes: - simplify ->core_dump() - change exit_mm() to clear ->mm first, then wait for ->core_done. this makes the coredumping process visible to oom_kill - kill mm->core_done Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/exit.c')
-rw-r--r--kernel/exit.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 63d82957baae..b66f0d55c791 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -664,6 +664,7 @@ assign_new_owner:
664static void exit_mm(struct task_struct * tsk) 664static void exit_mm(struct task_struct * tsk)
665{ 665{
666 struct mm_struct *mm = tsk->mm; 666 struct mm_struct *mm = tsk->mm;
667 struct core_state *core_state;
667 668
668 mm_release(tsk, mm); 669 mm_release(tsk, mm);
669 if (!mm) 670 if (!mm)
@@ -676,11 +677,19 @@ static void exit_mm(struct task_struct * tsk)
676 * group with ->mm != NULL. 677 * group with ->mm != NULL.
677 */ 678 */
678 down_read(&mm->mmap_sem); 679 down_read(&mm->mmap_sem);
679 if (mm->core_state) { 680 core_state = mm->core_state;
681 if (core_state) {
682 struct core_thread self;
680 up_read(&mm->mmap_sem); 683 up_read(&mm->mmap_sem);
681 684
682 if (atomic_dec_and_test(&mm->core_state->nr_threads)) 685 self.task = tsk;
683 complete(&mm->core_state->startup); 686 self.next = xchg(&core_state->dumper.next, &self);
687 /*
688 * Implies mb(), the result of xchg() must be visible
689 * to core_state->dumper.
690 */
691 if (atomic_dec_and_test(&core_state->nr_threads))
692 complete(&core_state->startup);
684 693
685 wait_for_completion(&mm->core_done); 694 wait_for_completion(&mm->core_done);
686 down_read(&mm->mmap_sem); 695 down_read(&mm->mmap_sem);