From: Eric Dumazet <eric.dumazet@gmail.com>
To: Tom Herbert <therbert@google.com>
Cc: Bill Fink <billfink@mindspring.com>,
David Miller <davem@davemloft.net>,
netdev@vger.kernel.org
Subject: Re: [PATCH] tcp: SO_TIMESTAMP implementation for TCP
Date: Sat, 01 May 2010 08:00:48 +0200 [thread overview]
Message-ID: <1272693648.2230.78.camel@edumazet-laptop> (raw)
In-Reply-To: <AANLkTimFjDNgXdMGpVpO7Gi38ROlww1Fa7IKA1ASBKOV@mail.gmail.com>
Le vendredi 30 avril 2010 à 22:40 -0700, Tom Herbert a écrit :
> > 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, did you tried to reuse existing skb or sk tstamps ?
next prev parent reply other threads:[~2010-05-01 6:00 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
2010-05-01 6:00 ` Eric Dumazet [this message]
2010-05-01 5:31 ` Tom Herbert
2010-05-01 12:06 ` Paul LeoNerd Evans
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