netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: "Erdogan, Tahsin" <trdgn@amazon.com>,
	 "herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
	 "jasowang@redhat.com" <jasowang@redhat.com>,
	 "willemdebruijn.kernel@gmail.com"
	<willemdebruijn.kernel@gmail.com>,
	 "davem@davemloft.net" <davem@davemloft.net>,
	 "kuba@kernel.org" <kuba@kernel.org>,
	 "edumazet@google.com" <edumazet@google.com>,
	 "pabeni@redhat.com" <pabeni@redhat.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	 "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] tun: avoid high-order page allocation for packet header
Date: Wed, 09 Aug 2023 10:01:24 -0400	[thread overview]
Message-ID: <64d39c34bbd92_26add629414@willemb.c.googlers.com.notmuch> (raw)
In-Reply-To: <fc219fe5f8c8dec66a6fdff08f40acf714b8328b.camel@amazon.com>

Erdogan, Tahsin wrote:
> On Wed, 2023-08-09 at 09:18 -0400, Willem de Bruijn wrote:
> > Tun sendmsg is a special case, only used by vhost-net from inside the
> > kernel. Arguably consistency with packet_snd/packet_alloc_skb would
> > be
> > more important. That said, this makes sense to me. I assume your
> > configuring a device with very large MTU?
> 
> That's right. I am setting MTU to 9100 in my test.

Makes sense. That's not even that large.

Please address the commit message points about virtio_net_hdr.hdr_len
and write() vs writev().

A writev() specific solution could even take the first iov length as
hint. Note that I'm not suggesting that. IFF_NAPI_FRAGS already does
exactly that, plus the geometry of subsequent frags.

  reply	other threads:[~2023-08-09 14:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-08 23:09 [PATCH v3] tun: avoid high-order page allocation for packet header Tahsin Erdogan
2023-08-09 13:18 ` Willem de Bruijn
2023-08-09 13:53   ` Erdogan, Tahsin
2023-08-09 14:01     ` Willem de Bruijn [this message]
2023-08-09 15:01       ` Erdogan, Tahsin

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=64d39c34bbd92_26add629414@willemb.c.googlers.com.notmuch \
    --to=willemdebruijn.kernel@gmail.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=jasowang@redhat.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=trdgn@amazon.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).