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From: Jeff Garzik <jgarzik@pobox.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Gortmaker <penguin@muskoka.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] 2.6.9 Use skb_padto() in drivers/net/8390.c
Date: Sat, 19 Feb 2005 00:20:44 -0500	[thread overview]
Message-ID: <4216CCAC.1050807@pobox.com> (raw)
In-Reply-To: <1105381093.12028.81.camel@localhost.localdomain>

Alan Cox wrote:
> On Llu, 2005-01-10 at 02:41, Paul Gortmaker wrote:
> 
>>Using rdtscl over the  area affected by the patch on the two variants for a
>>sample  of 234 small packets, I see an average of 4141 for using the
>>existing stack scratch area, and 4162 for using skb_padto.   That is a
>>difference of about 0.5%, which is significantly less than the typical
>>spread in the samples themselves.  To help give a relevant scale,  feeding
>>it a larger 1400 byte packet comes in at around 60,000 cycles on this
>>particular box.   Am I being optimistic to see this as good news -- meaning
>>that there is no longer a need for driver specific padto implementations,
>>whereas it looks like there was back when you did your tests? 
> 
> 
> It means that padto has improved a lot (or the underlying allocators).
> It also still means the patch makes the code slower and introduces
> changes that have no benefit into the kernel, so while its good to see
> its not relevant its still a pointless change.

So the verdict is to revert?

	Jeff




  reply	other threads:[~2005-02-19  5:21 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <41DED9FA.7080106@pobox.com>
2005-01-08  8:33 ` [PATCH] 2.6.9 Use skb_padto() in drivers/net/8390.c] Paul Gortmaker
2005-01-08 15:45   ` Alan Cox
2005-01-10  2:41     ` [PATCH] 2.6.9 Use skb_padto() in drivers/net/8390.c Paul Gortmaker
2005-01-10 18:28       ` Alan Cox
2005-02-19  5:20         ` Jeff Garzik [this message]
2005-02-19 14:06           ` Alan Cox
     [not found] <200501070309.j0739IG6007753@hera.kernel.org>
2005-01-07 15:46 ` Alan Cox

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