From: David Laight <David.Laight@ACULAB.COM>
To: "'Herbert Xu'" <herbert@gondor.apana.org.au>,
Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: "Hans Westgaard Ry" <hans.westgaard.ry@oracle.com>,
"David S. Miller" <davem@davemloft.net>,
"Alexey Kuznetsov" <kuznet@ms2.inr.ac.ru>,
"James Morris" <jmorris@namei.org>,
"Hideaki YOSHIFUJI" <yoshfuji@linux-ipv6.org>,
"Patrick McHardy" <kaber@trash.net>,
"Tom Herbert" <tom@herbertland.com>,
"Pablo Neira Ayuso" <pablo@netfilter.org>,
"Eric Dumazet" <edumazet@google.com>,
"Florian Westphal" <fw@strlen.de>,
"Jiri Pirko" <jiri@resnulli.us>,
"Alexander Duyck" <alexander.h.duyck@redhat.com>,
"Michal Hocko" <mhocko@suse.com>,
"Linus Lüssing" <linus.luessing@c0d3.blue>,
"Tejun Heo" <tj@kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Alexey Kodanev" <alexey.kodanev@oracle.com>,
"Håkon Bugge" <haakon.bugge@oracle.com>,
"open list" <linux-kernel@vger.kernel.org>,
"open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>
Subject: RE: [PATCH v3] net:Add sysctl_max_skb_frags
Date: Wed, 3 Feb 2016 17:36:24 +0000 [thread overview]
Message-ID: <063D6719AE5E284EB5DD2968C1650D6D1CCD585F@AcuExch.aculab.com> (raw)
In-Reply-To: <20160203122052.GA28619@gondor.apana.org.au>
From: Herbert Xu
> Sent: 03 February 2016 12:21
> On Wed, Feb 03, 2016 at 12:36:21PM +0100, Hannes Frederic Sowa wrote:
> >
> > Agreed that it feels like a hack, but a rather simple one. I would
> > consider this to be just a performance improvement. We certainly need
> > a slow-path when virtio drivers submit gso packets to the stack (and
> > already discussed with Hans). The sysctl can't help here. But without
> > the sysctl the packets would constantly hit the slow-path in case of
> > e.g. IPoIB and that would also be rather bad.
>
> So you want to penalise every NIC in the system if just one of
> them is broken? This is insane. Just do the partial linearisation
> in that one driver that needs it and not only won't you have to
> penalise anyone else but you still get the best result for that
> driver that needs it.
>
> Besides, you have to implement the linearisation anyway because
> of virtualisation.
And if a MAC driver needs to linearize a tx frame it might as well
copy it into a separately allocated tx buffer area.
Indeed it can copy fragments until the number left is less than the
fragment limit.
David
next prev parent reply other threads:[~2016-02-03 17:39 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-06 13:16 [PATCH] net: add per device sg_max_frags for skb Hans Westgaard Ry
2016-01-06 13:16 ` Hans Westgaard Ry
2016-01-06 13:59 ` David Laight
2016-01-06 13:59 ` David Laight
2016-01-08 9:55 ` Hans Westgaard Ry
2016-01-08 9:55 ` Hans Westgaard Ry
2016-01-08 10:33 ` David Laight
2016-01-08 10:33 ` David Laight
2016-01-08 11:47 ` Hannes Frederic Sowa
2016-01-08 11:47 ` Hannes Frederic Sowa
2016-01-13 13:57 ` Hans Westgaard Ry
2016-01-13 13:57 ` Hans Westgaard Ry
2016-01-13 14:19 ` Eric Dumazet
2016-01-13 14:19 ` Eric Dumazet
2016-01-13 14:20 ` Eric Dumazet
2016-01-13 14:20 ` Eric Dumazet
2016-01-13 15:07 ` Hannes Frederic Sowa
2016-01-13 15:07 ` Hannes Frederic Sowa
2016-01-13 15:38 ` David Miller
2016-01-13 15:44 ` Eric Dumazet
2016-01-13 15:44 ` Eric Dumazet
2016-01-13 21:07 ` Eric W. Biederman
2016-01-13 21:07 ` Eric W. Biederman
2016-01-27 13:20 ` [PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags Hans Westgaard Ry
2016-01-27 15:15 ` Eric Dumazet
2016-01-27 18:12 ` Hannes Frederic Sowa
2016-02-01 13:12 ` Hans Westgaard Ry
2016-01-27 20:13 ` David Miller
2016-02-03 8:26 ` [PATCH v3] net:Add sysctl_max_skb_frags Hans Westgaard Ry
2016-02-03 8:26 ` Hans Westgaard Ry
2016-02-03 11:25 ` Herbert Xu
2016-02-03 11:36 ` Hannes Frederic Sowa
2016-02-03 12:20 ` Herbert Xu
2016-02-03 14:03 ` Hannes Frederic Sowa
2016-02-03 14:30 ` Eric Dumazet
2016-02-03 14:30 ` Eric Dumazet
2016-02-03 17:36 ` David Laight [this message]
2016-02-03 15:58 ` Alexander Duyck
2016-02-03 16:07 ` Eric Dumazet
2016-02-03 16:07 ` Eric Dumazet
2016-02-03 17:43 ` Alexander Duyck
2016-02-03 17:43 ` Alexander Duyck
2016-02-03 17:54 ` Eric Dumazet
2016-02-03 17:54 ` Eric Dumazet
2016-02-03 18:24 ` Alexander Duyck
2016-02-03 18:24 ` Alexander Duyck
2016-02-03 19:23 ` Eric Dumazet
2016-02-03 19:23 ` Eric Dumazet
2016-02-03 21:03 ` Alexander Duyck
2016-02-09 9:30 ` David Miller
2016-01-06 14:05 ` [PATCH] net: add per device sg_max_frags for skb Eric Dumazet
2016-01-06 14:05 ` Eric Dumazet
2016-01-08 10:01 ` Hans Westgaard Ry
2016-01-08 10:01 ` Hans Westgaard Ry
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