From: Simon Horman <horms@kernel.org>
To: Corinna Vinschen <vinschen@redhat.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
intel-wired-lan@lists.osuosl.org,
Nikolay Aleksandrov <razor@blackwall.org>,
Jason Xing <kerneljasonxing@gmail.com>,
Paolo Abeni <pabeni@redhat.com>, Jakub Kicinski <kuba@kernel.org>,
Eric Dumazet <edumazet@google.com>,
"David S . Miller" <davem@davemloft.net>,
Tony Nguyen <anthony.l.nguyen@intel.com>,
Jesse Brandeburg <jesse.brandeburg@intel.com>
Subject: Re: [PATCH net v2] igb: cope with large MAX_SKB_FRAGS
Date: Sun, 28 Apr 2024 14:05:47 +0100 [thread overview]
Message-ID: <20240428130547.GV516117@kernel.org> (raw)
In-Reply-To: <20240423134731.918157-1-vinschen@redhat.com>
On Tue, Apr 23, 2024 at 03:47:31PM +0200, Corinna Vinschen wrote:
> From: Paolo Abeni <pabeni@redhat.com>
>
> Sabrina reports that the igb driver does not cope well with large
> MAX_SKB_FRAG values: setting MAX_SKB_FRAG to 45 causes payload
> corruption on TX.
>
> An easy reproducer is to run ssh to connect to the machine. With
> MAX_SKB_FRAGS=17 it works, with MAX_SKB_FRAGS=45 it fails.
>
> The root cause of the issue is that the driver does not take into
> account properly the (possibly large) shared info size when selecting
> the ring layout, and will try to fit two packets inside the same 4K
> page even when the 1st fraglist will trump over the 2nd head.
>
> Address the issue forcing the driver to fit a single packet per page,
> leaving there enough room to store the (currently) largest possible
> skb_shared_info.
>
> Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAG")
nit: The trailing "S" in the subject for the fixes tag seems to have been lost.
Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAGS")
> Reported-by: Jan Tluka <jtluka@redhat.com>
> Reported-by: Jirka Hladky <jhladky@redhat.com>
> Reported-by: Sabrina Dubroca <sd@queasysnail.net>
> Tested-by: Sabrina Dubroca <sd@queasysnail.net>
> Tested-by: Corinna Vinschen <vinschen@redhat.com>
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
...
prev parent reply other threads:[~2024-04-28 13:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-23 13:47 [PATCH net v2] igb: cope with large MAX_SKB_FRAGS Corinna Vinschen
2024-04-23 14:10 ` Eric Dumazet
2024-04-26 14:30 ` Corinna Vinschen
2024-04-26 17:54 ` Eric Dumazet
2024-04-28 13:05 ` Simon Horman [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240428130547.GV516117@kernel.org \
--to=horms@kernel.org \
--cc=anthony.l.nguyen@intel.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=intel-wired-lan@lists.osuosl.org \
--cc=jesse.brandeburg@intel.com \
--cc=kerneljasonxing@gmail.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=razor@blackwall.org \
--cc=vinschen@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).