From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754612Ab3EaKF5 (ORCPT ); Fri, 31 May 2013 06:05:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30820 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753897Ab3EaKDo (ORCPT ); Fri, 31 May 2013 06:03:44 -0400 From: Jason Wang To: davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com Cc: Jason Wang Subject: [net-next rfc V2 1/8] macvtap: do not add self to waitqueue if doing a nonblock read Date: Fri, 31 May 2013 17:53:18 +0800 Message-Id: <1369994005-5943-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1369994005-5943-1-git-send-email-jasowang@redhat.com> References: <1369994005-5943-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There's no need to add self to waitqueue if doing a nonblock read. This could help to avoid the spinlock contention. Signed-off-by: Jason Wang --- drivers/net/macvtap.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 59e9605..2395062 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -845,7 +845,9 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb, ssize_t ret = 0; while (len) { - prepare_to_wait(sk_sleep(&q->sk), &wait, TASK_INTERRUPTIBLE); + if (!noblock) + prepare_to_wait(sk_sleep(&q->sk), &wait, + TASK_INTERRUPTIBLE); /* Read frames from the queue */ skb = skb_dequeue(&q->sk.sk_receive_queue); @@ -867,7 +869,8 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb, break; } - finish_wait(sk_sleep(&q->sk), &wait); + if (!noblock) + finish_wait(sk_sleep(&q->sk), &wait); return ret; } -- 1.7.1