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From: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
To: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, caitlinb@broadcom.com, kelly@au1.ibm.com,
	rusty@rustcorp.com.au
Subject: Re: Initial benchmarks of some VJ ideas [mmap memcpy vs copy_to_user].
Date: Fri, 12 May 2006 11:54:07 +0400	[thread overview]
Message-ID: <20060512075407.GB11880@2ka.mipt.ru> (raw)
In-Reply-To: <20060511.115409.89709859.davem@davemloft.net>

On Thu, May 11, 2006 at 11:54:09AM -0700, David S. Miller (davem@davemloft.net) wrote:
> BTW you make another massively critical error in your analysis of TCP
> profiles.
> 
> You mention that "tcp_v4_rcv()" shows up in your profiles and not
> __inet_lookup().  This __inet_lookup() is inlined, and thus it's cost
> shows up as "tcp_v4_rcv()".  I find such oversight amazing for someone
> as careful about details as you are :-)

Ugh, my fault.
But tcp_v4_rcv() also does a lot of other things which more likely
pushes this function in profile statistics :)

> I would suggest to look at instruction level profile hits, it makes
> such mistakes in analysis almost impossible :-)

It is much more challenging than running oprofile, so it will be
postponed for a while :)

-- 
	Evgeniy Polyakov

      parent reply	other threads:[~2006-05-12  7:55 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-05-08 12:24 Initial benchmarks of some VJ ideas [mmap memcpy vs copy_to_user] Evgeniy Polyakov
2006-05-08 19:51 ` Evgeniy Polyakov
2006-05-08 20:15   ` David S. Miller
2006-05-10 19:58 ` David S. Miller
2006-05-11  6:40   ` Evgeniy Polyakov
2006-05-11  7:07     ` David S. Miller
2006-05-11  8:30       ` Evgeniy Polyakov
2006-05-11 16:18         ` Evgeniy Polyakov
2006-05-11 18:54           ` David S. Miller
2006-05-11 19:30             ` Rick Jones
2006-05-12  7:54             ` Evgeniy Polyakov [this message]

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