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To: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: "linux-kernel" <linux-kernel@vger.kernel.org>
Subject: Re: [patch] speed up single bio_vec allocation
References: <000301c717da$3ecf4970$2589030a@amr.corp.intel.com>
From: Andi Kleen <ak@suse.de>
Date: 08 Dec 2006 03:27:54 +0100
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"Chen, Kenneth W" <kenneth.w.chen@intel.com> writes:
> 
> I tried to use cache_line_size() to find out the alignment of struct bio, but
> stumbled on that it is a runtime function for x86_64.

It's a single global variable access:

#define cache_line_size() (boot_cpu_data.x86_cache_alignment)

Or do you mean it caused cache misses?  boot_cpu_data is cache aligned
and practically read only, so there shouldn't be any false sharing at least.

-Andi