From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: Major network performance regression in 3.7 Date: Sat, 05 Jan 2013 18:16:31 -0800 Message-ID: <1357438591.1678.5205.camel@edumazet-glaptop> References: <20130105214958.GA19814@1wt.eu> <1357427926.1678.4771.camel@edumazet-glaptop> <20130105232913.GQ16031@1wt.eu> <1357430523.1678.4901.camel@edumazet-glaptop> <20130106005053.GS16031@1wt.eu> <1357435276.1678.5067.camel@edumazet-glaptop> <20130106013027.GV16031@1wt.eu> <1357436430.1678.5111.camel@edumazet-glaptop> <1357437086.1678.5135.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Willy Tarreau Return-path: Received: from mail-da0-f51.google.com ([209.85.210.51]:39664 "EHLO mail-da0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755120Ab3AFCQe (ORCPT ); Sat, 5 Jan 2013 21:16:34 -0500 In-Reply-To: <1357437086.1678.5135.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2013-01-05 at 17:51 -0800, Eric Dumazet wrote: > On Sat, 2013-01-05 at 17:40 -0800, Eric Dumazet wrote: > > On Sun, 2013-01-06 at 02:30 +0100, Willy Tarreau wrote: > > > > > Ah interesting because these were some of the mm patches that I had > > > tried to revert. > > > > Hmm, or we should fix __skb_splice_bits() > > > > I'll send a patch. > > > > Could you try the following ? Or more exactly... diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3ab989b..01f222c 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1736,11 +1736,8 @@ static bool __splice_segment(struct page *page, unsigned int poff, return false; } - /* ignore any bits we already processed */ - if (*off) { - __segment_seek(&page, &poff, &plen, *off); - *off = 0; - } + __segment_seek(&page, &poff, &plen, *off); + *off = 0; do { unsigned int flen = min(*len, plen); @@ -1768,14 +1765,15 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, struct splice_pipe_desc *spd, struct sock *sk) { int seg; + struct page *page = virt_to_page(skb->data); + unsigned int poff = skb->data - (unsigned char *)page_address(page); /* map the linear part : * If skb->head_frag is set, this 'linear' part is backed by a * fragment, and if the head is not shared with any clones then * we can avoid a copy since we own the head portion of this page. */ - if (__splice_segment(virt_to_page(skb->data), - (unsigned long) skb->data & (PAGE_SIZE - 1), + if (__splice_segment(page, poff, skb_headlen(skb), offset, len, skb, spd, skb_head_is_locked(skb),