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Re: [Xen-devel] [PATCH] x86: remove use of per-domain lock from page tab

To: Jan Beulich <jbeulich@xxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] x86: remove use of per-domain lock from page table entry handling
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 22 Apr 2008 14:30:20 +0100
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Thread-topic: [Xen-devel] [PATCH] x86: remove use of per-domain lock from page table entry handling
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On 22/4/08 14:01, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:

> This is only a first step, the use of the domain lock in do_mmuext_op()
> and do_set_gdt() still need looking at, as do the assertions of the
> lock being held in create_grant_{pte,va}_mapping().
> This change results in a 5% performance improvement for kernel builds
> on dual-socket quad-core systems (which is what I used for reference
> for both 32- and 64-bit). Along with that, the amount of time reported
> as spent in the kernel gets reduced by almost 25% (the fraction of time
> spent in the kernel is generally reported significantly higher under
> Xen than with a native kernel).

I'm pretty sure we don't need per-page locks.

 -- Keir

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