coredump: turn core_state->nr_threads into atomic_t

Turn core_state->nr_threads into atomic_t and kill now unneeded
down_write(&mm->mmap_sem) in exit_mm().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2008-07-25 01:47:42 -07:00 committed by Linus Torvalds
parent 8cd9c24912
commit c5f1cc8c18
3 changed files with 4 additions and 5 deletions

View File

@ -1591,7 +1591,7 @@ static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
}
rcu_read_unlock();
done:
core_state->nr_threads = nr;
atomic_set(&core_state->nr_threads, nr);
return nr;
}

View File

@ -160,7 +160,7 @@ struct vm_area_struct {
};
struct core_state {
int nr_threads;
atomic_t nr_threads;
struct completion startup;
};

View File

@ -678,10 +678,9 @@ static void exit_mm(struct task_struct * tsk)
down_read(&mm->mmap_sem);
if (mm->core_state) {
up_read(&mm->mmap_sem);
down_write(&mm->mmap_sem);
if (!--mm->core_state->nr_threads)
if (atomic_dec_and_test(&mm->core_state->nr_threads))
complete(&mm->core_state->startup);
up_write(&mm->mmap_sem);
wait_for_completion(&mm->core_done);
down_read(&mm->mmap_sem);