From: Tom Herbert <therbert@google.com>
To: Bill Fink <billfink@mindspring.com>
Cc: David Miller <davem@davemloft.net>, netdev@vger.kernel.org
Subject: Re: [PATCH] tcp: SO_TIMESTAMP implementation for TCP
Date: Fri, 30 Apr 2010 22:40:38 -0700 [thread overview]
Message-ID: <AANLkTimFjDNgXdMGpVpO7Gi38ROlww1Fa7IKA1ASBKOV@mail.gmail.com> (raw)
In-Reply-To: <20100501010735.dfe097bc.billfink@mindspring.com>
> Not being a kernel hacker, I will naively ask if the kernel tracing
> facility could somehow be used to provide the desired info (or could
> be modified to provide it).
>
We did consider kernel tracing (more in the context of implementing
RFC 4898). In the case of trying get per packet timestamps,
correlating a ktrace event with an application message is probably too
high to make it practical. If it weren't for the cost of
timestamp'ing every single skb being received, we'd probably have
SO_TIMESTAMP turned on permanently for many connections. For now
we're settling for a percentage of messages for sampling.
Tom
next prev parent reply other threads:[~2010-05-01 5:40 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-30 6:07 [PATCH] tcp: SO_TIMESTAMP implementation for TCP Tom Herbert
2010-04-30 6:39 ` David Miller
2010-04-30 7:58 ` Tom Herbert
2010-04-30 23:41 ` David Miller
2010-05-01 5:07 ` Bill Fink
2010-05-01 5:40 ` Tom Herbert [this message]
2010-05-01 6:00 ` Eric Dumazet
2010-05-01 5:31 ` Tom Herbert
2010-05-01 12:06 ` Paul LeoNerd Evans
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=AANLkTimFjDNgXdMGpVpO7Gi38ROlww1Fa7IKA1ASBKOV@mail.gmail.com \
--to=therbert@google.com \
--cc=billfink@mindspring.com \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
/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).