From: Dave Hansen <dave.hansen@intel.com>
To: Wilco Dijkstra <wdijkstr@arm.com>, linux-mm@kvack.org
Subject: Re: Background page clearing
Date: Fri, 25 Jul 2014 08:19:44 -0700 [thread overview]
Message-ID: <53D27590.2090500@intel.com> (raw)
In-Reply-To: <000001cfa81a$110d15c0$33274140$@com>
On 07/25/2014 08:06 AM, Wilco Dijkstra wrote:
> Is there a reason Linux does not do background page clearing like other OSes to reduce this
> overhead? It would be a good fit for typical mobile workloads (bursts of high activity followed by
> periods of low activity).
If the page is being allocated, it is about to be used and be brought in
to the CPU's cache. If we zero it close to this use, we only pay to
bring it in to the CPU's cache once. Or so goes the theory...
I tried a zero-on-free implementation a year or so ago. It helped some
workloads and hurt others. The gains were not large enough or
widespread enough to merit pushing it in to the kernel.
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next prev parent reply other threads:[~2014-07-25 15:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-25 15:06 Wilco Dijkstra
2014-07-25 15:19 ` Dave Hansen [this message]
2014-07-25 16:27 ` Wilco Dijkstra
2014-07-25 16:32 ` Dave Hansen
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