From: Oleg Nesterov <oleg@tv-sign.ru>
To: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>,
Srivatsa Vaddagiri <vatsa@in.ibm.com>,
Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH] rcu_do_batch: make ->qlen decrement irq safe
Date: Mon, 11 Sep 2006 01:32:43 +0400 [thread overview]
Message-ID: <20060910213242.GB437@oleg> (raw)
In-Reply-To: <20060910205827.GD4690@in.ibm.com>
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>
--- rc6-mm1/kernel/rcupdate.c~ 2006-08-22 16:22:49.000000000 +0400
+++ rc6-mm1/kernel/rcupdate.c 2006-09-11 01:24:17.000000000 +0400
@@ -241,12 +241,16 @@ static void rcu_do_batch(struct rcu_data
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
next prev parent reply other threads:[~2006-09-10 21:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-10 15:08 rcu_do_batch: rcu_data->qlen is not irq safe Oleg Nesterov
2006-09-10 20:58 ` Dipankar Sarma
2006-09-10 21:27 ` Oleg Nesterov
2006-09-10 21:32 ` Oleg Nesterov [this message]
2006-09-10 22:17 ` [PATCH] rcu_do_batch: make ->qlen decrement " Dipankar Sarma
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