From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: netdev@vger.kernel.org, ycheng@google.com
Subject: Re: [PATCH net-next] tcp: prepare skbs for better sack shifting
Date: Sat, 17 Sep 2016 10:05:27 -0400 (EDT) [thread overview]
Message-ID: <20160917.100527.590702360910250037.davem@davemloft.net> (raw)
In-Reply-To: <1473957182.22679.50.camel@edumazet-glaptop3.roam.corp.google.com>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 15 Sep 2016 09:33:02 -0700
> From: Eric Dumazet <edumazet@google.com>
>
> With large BDP TCP flows and lossy networks, it is very important
> to keep a low number of skbs in the write queue.
>
> RACK and SACK processing can perform a linear scan of it.
>
> We should avoid putting any payload in skb->head, so that SACK
> shifting can be done if needed.
>
> With this patch, we allow to pack ~0.5 MB per skb instead of
> the 64KB initially cooked at tcp_sendmsg() time.
>
> This gives a reduction of number of skbs in write queue by eight.
> tcp_rack_detect_loss() likes this.
>
> We still allow payload in skb->head for first skb put in the queue,
> to not impact RPC workloads.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Yuchung Cheng <ycheng@google.com>
Applied.
prev parent reply other threads:[~2016-09-17 14:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-15 16:33 [PATCH net-next] tcp: prepare skbs for better sack shifting Eric Dumazet
2016-09-15 17:52 ` Yuchung Cheng
2016-09-17 14:05 ` David Miller [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=20160917.100527.590702360910250037.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=ycheng@google.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).