From: Valdis.Kletnieks@vt.edu
To: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Cc: David Miller <davem@davemloft.net>,
dada1@cosmosbay.com, herbert@gondor.apana.org.au,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: tbench regression in 2.6.25-rc1
Date: Mon, 18 Feb 2008 12:33:53 -0500 [thread overview]
Message-ID: <20040.1203356033@turing-police.cc.vt.edu> (raw)
In-Reply-To: Your message of "Mon, 18 Feb 2008 16:12:38 +0800." <1203322358.3027.200.camel@ymzhang>
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On Mon, 18 Feb 2008 16:12:38 +0800, "Zhang, Yanmin" said:
> I also think __refcnt is the key. I did a new testing by adding 2 unsigned long
> pading before lastuse, so the 3 members are moved to next cache line. The performance is
> recovered.
>
> How about below patch? Almost all performance is recovered with the new patch.
>
> Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Could you add a comment someplace that says "refcnt wants to be on a different
cache line from input/output/ops or performance tanks badly", to warn some
future kernel hacker who starts adding new fields to the structure?
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next prev parent reply other threads:[~2008-02-18 17:35 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-15 1:52 tbench regression in 2.6.25-rc1 Zhang, Yanmin
2008-02-15 6:05 ` Eric Dumazet
2008-02-15 6:30 ` Zhang, Yanmin
2008-02-15 14:21 ` Eric Dumazet
2008-02-15 23:22 ` David Miller
2008-02-18 8:12 ` Zhang, Yanmin
2008-02-18 10:11 ` Eric Dumazet
2008-02-19 2:44 ` Zhang, Yanmin
2008-02-19 7:35 ` Eric Dumazet
2008-02-19 8:40 ` Zhang, Yanmin
2008-02-18 17:33 ` Valdis.Kletnieks [this message]
2008-02-19 6:51 ` Zhang, Yanmin
2008-02-19 7:40 ` Eric Dumazet
2008-02-20 7:04 ` Zhang, Yanmin
2008-02-20 7:38 ` Eric Dumazet
2008-02-20 8:14 ` David Miller
2008-02-20 8:41 ` Zhang, Yanmin
2008-02-18 1:39 ` Zhang, Yanmin
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