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author | Oleg Nesterov <oleg@redhat.com> | 2010-05-26 14:43:10 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-27 09:12:45 -0700 |
commit | 9c3391684415c9dca239130d9e433a60a4edf04b (patch) | |
tree | a8019b964c625cfeeda0e9d85bafa48991546212 /fs/ubifs/io.c | |
parent | 269b005a28e124a341df4adef2c3661cf7371fcc (diff) | |
download | op-kernel-dev-9c3391684415c9dca239130d9e433a60a4edf04b.zip op-kernel-dev-9c3391684415c9dca239130d9e433a60a4edf04b.tar.gz |
exit: exit_notify() can trust signal->notify_count < 0
signal_struct->count in its current form must die.
- it has no reasons to be atomic_t
- it looks like a reference counter, but it is not
- otoh, we really need to make task->signal refcountable, just look at
the extremely ugly task_rq_unlock_wait() called from __exit_signals().
- we should change the lifetime rules for task->signal, it should be
pinned to task_struct. We have a lot of code which can be simplified
after that.
- it is not needed! while the code is correct, any usage of this
counter is artificial, except fs/proc uses it correctly to show the
number of threads.
This series removes the usage of sig->count from exit pathes.
This patch:
Now that Veaceslav changed copy_signal() to use zalloc(), exit_notify()
can just check notify_count < 0 to ensure the execing sub-threads needs
the notification from us. No need to do other checks, notify_count != 0
must always mean ->group_exit_task != NULL is waiting for us.
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 'fs/ubifs/io.c')
0 files changed, 0 insertions, 0 deletions