[PATCH] rcu_do_batch: make ->qlen decrement irq safe

rcu_do_batch() decrements rdp->qlen with irqs enabled.  This is not good,
it can also be modified by call_rcu() from interrupt.

Decrement ->qlen once with irqs disabled, after a main loop.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Oleg Nesterov 2006-09-12 20:35:55 -07:00 committed by Linus Torvalds
parent 7fbb36451a
commit dd9daa221e

View file

@ -241,12 +241,16 @@ static void rcu_do_batch(struct rcu_data *rdp)
next = rdp->donelist = list->next;
list->func(list);
list = next;
rdp->qlen--;
if (++count >= rdp->blimit)
break;
}
local_irq_disable();
rdp->qlen -= count;
local_irq_enable();
if (rdp->blimit == INT_MAX && rdp->qlen <= qlowmark)
rdp->blimit = blimit;
if (!rdp->donelist)
rdp->donetail = &rdp->donelist;
else