From: Zoltan Kiss <zoltan.kiss@citrix.com>
To: Eric Dumazet <eric.dumazet@gmail.com>,
Sander Eikelenboom <linux@eikelenboom.it>
Cc: Ian Campbell <Ian.Campbell@citrix.com>,
"David S. Miller" <davem@davemloft.net>, <netdev@vger.kernel.org>,
<xen-devel@lists.xen.org>
Subject: Re: [3.15-rc3] Bisected: xen-netback mangles packets between two guests on a bridge since merge of "TX grant mapping with SKBTX_DEV_ZEROCOPY instead of copy" series.
Date: Wed, 30 Apr 2014 21:40:55 +0100 [thread overview]
Message-ID: <53615FD7.8090803@citrix.com> (raw)
In-Reply-To: <1398871446.29914.163.camel@edumazet-glaptop2.roam.corp.google.com>
On 30/04/14 16:24, Eric Dumazet wrote:
> On Wed, 2014-04-30 at 12:45 +0200, Sander Eikelenboom wrote:
>
> This looks like skb->data_len is not properly set
>
> (Small note :
> alloc_page(GFP_ATOMIC|__GFP_COLD) should be a plain
> alloc_page(GFP_ATOMIC) : We prefer a page that has been used recently to
> avoid cache misses if possible.
> )
>
> This probably confuses skb_try_coalesce()
>
> My guess is xenvif_get_requests() forgets to init nskb->len /
> nskb->data_len for the skb that is attached to frag_list
xenvif_get_requests() calls alloc_skb() which inits these values to zero
>
> So the "skb->data_len += nskb->len;" at line 1353 is probably a nop.
next prev parent reply other threads:[~2014-04-30 20:40 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-30 10:45 [3.15-rc3] Bisected: xen-netback mangles packets between two guests on a bridge since merge of "TX grant mapping with SKBTX_DEV_ZEROCOPY instead of copy" series Sander Eikelenboom
2014-04-30 15:24 ` Eric Dumazet
2014-04-30 20:40 ` Zoltan Kiss [this message]
2014-04-30 20:53 ` Zoltan Kiss
2014-04-30 22:25 ` Sander Eikelenboom
2014-05-01 13:37 ` Zoltan Kiss
2014-05-01 13:59 ` Sander Eikelenboom
2014-05-01 15:46 ` Zoltan Kiss
2014-05-01 17:39 ` Sander Eikelenboom
2014-05-01 17:46 ` Eric Dumazet
2014-05-01 19:39 ` [Xen-devel] " Sander Eikelenboom
2014-05-02 14:00 ` Zoltan Kiss
2014-05-02 14:06 ` Sander Eikelenboom
2014-05-02 14:47 ` Zoltan Kiss
2014-05-02 15:21 ` Eric Dumazet
2014-05-02 15:26 ` Zoltan Kiss
2014-05-02 16:28 ` Sander Eikelenboom
2014-05-02 16:45 ` Zoltan Kiss
2014-05-05 10:19 ` Sander Eikelenboom
2014-05-06 17:07 ` Steven Haigh
2014-05-06 17:13 ` Zoltan Kiss
2014-05-06 17:37 ` Sander Eikelenboom
2014-05-06 18:07 ` Steven Haigh
2014-05-07 8:16 ` [Xen-devel] " David Vrabel
2014-05-16 2:13 ` Steven Haigh
2014-05-06 17:08 ` [Xen-devel] " Zoltan Kiss
2014-05-06 17:10 ` Zoltan Kiss
2014-05-06 17:33 ` Sander Eikelenboom
2014-05-01 13:49 ` Zoltan Kiss
2014-05-01 14:05 ` Sander Eikelenboom
2014-05-01 15:16 ` Zoltan Kiss
2014-05-01 15:40 ` Sander Eikelenboom
2014-05-02 15:35 ` Eric Dumazet
2014-05-02 22:18 ` Sander Eikelenboom
2014-05-09 22:19 ` Neal Cardwell
2014-05-09 21:02 ` Zoltan Kiss
2014-05-13 13:40 ` Zoltan Kiss
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