From aa1757f90bea3f598b6e5d04d922a6a60200f1da Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 28 Mar 2006 16:11:12 -0800 Subject: [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index dc8f91bf9f8..b0b1ca9daa3 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -330,7 +330,7 @@ void __exit_sighand(struct task_struct *tsk) /* Ok, we're done with the signal handlers */ tsk->sighand = NULL; if (atomic_dec_and_test(&sighand->count)) - sighand_free(sighand); + kmem_cache_free(sighand_cachep, sighand); } void exit_sighand(struct task_struct *tsk) -- cgit v1.2.3-70-g09d2