From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] macvtap: use set_curren_state to ensure mb Date: Tue, 05 Jun 2012 13:05:29 +0200 Message-ID: <1338894329.2760.2318.camel@edumazet-glaptop> References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, arnd@arndb.de, zhiguo.hong@nsn.com, vikifang@juniper.net To: Hong zhi guo Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:54322 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933617Ab2FELFe (ORCPT ); Tue, 5 Jun 2012 07:05:34 -0400 Received: by bkcji2 with SMTP id ji2so4469734bkc.19 for ; Tue, 05 Jun 2012 04:05:33 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2012-06-05 at 18:46 +0800, Hong zhi guo wrote: > replace raw assignment of current->state with > set_current_state(TASK_...) to ensure memory barrier. > > Signed-off-by: Hong Zhiguo > --- > drivers/net/macvtap.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c > index 2ee56de..62754f6 100644 > --- a/drivers/net/macvtap.c > +++ b/drivers/net/macvtap.c > @@ -853,7 +853,7 @@ static ssize_t macvtap_do_read(struct > macvtap_queue *q, struct kiocb *iocb, > > add_wait_queue(sk_sleep(&q->sk), &wait); > while (len) { > - current->state = TASK_INTERRUPTIBLE; > + set_current_state(TASK_INTERRUPTIBLE); > > /* Read frames from the queue */ > skb = skb_dequeue(&q->sk.sk_receive_queue); > @@ -875,7 +875,7 @@ static ssize_t macvtap_do_read(struct > macvtap_queue *q, struct kiocb *iocb, > break; > } > > - current->state = TASK_RUNNING; > + set_current_state(TASK_RUNNING); > remove_wait_queue(sk_sleep(&q->sk), &wait); > return ret; > } Why not using the more standard : prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); and finish_wait(sk_sleep(sk), &wait);