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| author |   Oleg Nesterov <oleg@tv-sign.ru> | 2006-03-28 16:11:12 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-28 18:36:42 -0800 |
| commit | aa1757f90bea3f598b6e5d04d922a6a60200f1da (patch) | |
| tree | 4f8f3804b2595031d0b84de7086dc28375290f0d /fs/exec.c | |
| parent | [PATCH] release_task: replace open-coded ptrace_unlink() (diff) | |
| download | linux-dev-aa1757f90bea3f598b6e5d04d922a6a60200f1da.tar.xz linux-dev-aa1757f90bea3f598b6e5d04d922a6a60200f1da.zip | |
[PATCH] convert sighand_cache to use SLAB_DESTROY_BY_RCU
This patch borrows a clever Hugh's 'struct anon_vma' trick.
Without tasklist_lock held we can't trust task->sighand until we locked it
and re-checked that it is still the same.
But this means we don't need to defer 'kmem_cache_free(sighand)'. We can
return the memory to slab immediately, all we need is to be sure that
sighand->siglock can't dissapear inside rcu protected section.
To do so we need to initialize ->siglock inside ctor function,
SLAB_DESTROY_BY_RCU does the rest.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/exec.c b/fs/exec.c index 9046ad2b0614..950ebd43cdc3 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -768,7 +768,6 @@ no_thread_group: /* * Move our state over to newsighand and switch it in. */ - spin_lock_init(&newsighand->siglock); atomic_set(&newsighand->count, 1); memcpy(newsighand->action, oldsighand->action, sizeof(newsighand->action)); @@ -785,7 +784,7 @@ no_thread_group: write_unlock_irq(&tasklist_lock); if (atomic_dec_and_test(&oldsighand->count)) - sighand_free(oldsighand); + kmem_cache_free(sighand_cachep, oldsighand); } BUG_ON(!thread_group_leader(current)); |