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| author | Oleg Nesterov <oleg@redhat.com> | 2010-05-26 14:43:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-27 09:12:46 -0700 |
| commit | d344193a05da89c97e965da2c5cbf687d7385eae (patch) | |
| tree | 6267b68c31c4547f1749acd35d2a5bfaff919839 /kernel/exit.c | |
| parent | 09faef11df8c559a23e2405d123cb2683733a79a (diff) | |
| download | lwn-d344193a05da89c97e965da2c5cbf687d7385eae.tar.gz lwn-d344193a05da89c97e965da2c5cbf687d7385eae.zip | |
exit: avoid sig->count in de_thread/__exit_signal synchronization
de_thread() and __exit_signal() use signal_struct->count/notify_count for
synchronization. We can simplify the code and use ->notify_count only.
Instead of comparing these two counters, we can change de_thread() to set
->notify_count = nr_of_sub_threads, then change __exit_signal() to
dec-and-test this counter and notify group_exit_task.
Note that __exit_signal() checks "notify_count > 0" just for symmetry with
exit_notify(), we could just check it is != 0.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@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.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 59a104c673f7..9220967f4256 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -97,7 +97,7 @@ static void __exit_signal(struct task_struct *tsk) * If there is any task waiting for the group exit * then notify it: */ - if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) + if (sig->notify_count > 0 && !--sig->notify_count) wake_up_process(sig->group_exit_task); if (tsk == sig->curr_target) |