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From: "John Hawkes" <hawkes@sgi.com>
To: "Linux-Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] 2.5: push BKL out of llseek
Date: Fri, 1 Feb 2002 11:29:11 -0800
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From: "Dave Jones" <davej@suse.de>
>  did you benchmark with anything other than dbench ?

I've done substantial AIM7 benchmarking on a 28p ia64 NUMA system, and
llseek's BKL usage is a significant contributor to poor scaling.  For
500 AIM7 "tasks" and ext2 filesystems, waiting on the BKL consumes about
half of the available CPU cycles, and sys_lseek()'s usage is the most
significant cycle waster, followed by ext2_get_block() and
ext2_write_inode().  Anton's llseek patch from last November does make
a measurable improvement in AIM7 throughput.

--
John Hawkes
hawkes@sgi.com


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