From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754769Ab0CCOq4 (ORCPT ); Wed, 3 Mar 2010 09:46:56 -0500 Received: from mail.gmx.net ([213.165.64.20]:48823 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754467Ab0CCOqy (ORCPT ); Wed, 3 Mar 2010 09:46:54 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1+V1Aou62aVfEaI6R9kbCUti3UHJ1yyz4OHlGTF7d QEGRncISBriMlW Subject: Re: [rfc/rft][patch] should use scheduler sync hint in tcp_prequeue()? From: Mike Galbraith To: David Miller Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu In-Reply-To: <20100303.060529.195713861.davem@davemloft.net> References: <1267522901.25906.101.camel@marge.simson.net> <1267529273.2964.111.camel@edumazet-laptop> <20100303.060529.195713861.davem@davemloft.net> Content-Type: text/plain Date: Wed, 03 Mar 2010 15:46:50 +0100 Message-Id: <1267627610.6264.21.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.46999999999999997 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-03-03 at 06:05 -0800, David Miller wrote: > It definitely looks like an oversight to me and we should add > be using wake_up_interruptible_sync_poll() in tcp_prequeue() > as above. > > Ingo? Implied ack from network maintainer implies ship it to me. net: add scheduler sync hint to tcp_prequeue(). Decreases the odds wakee will suffer from frequent cache misses. Signed-off-by: Mike Galbraith Cc: David Miller LKML-Reference: diff --git a/include/net/tcp.h b/include/net/tcp.h index 34f5cc2..ba3fc64 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -939,7 +939,7 @@ static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb) tp->ucopy.memory = 0; } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { - wake_up_interruptible_poll(sk->sk_sleep, + wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN | POLLRDNORM | POLLRDBAND); if (!inet_csk_ack_scheduled(sk)) inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,