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From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: xen-devel@lists.xenproject.org
Subject: Re: x86 patch ping
Date: Fri, 15 Apr 2016 18:11:25 +0100	[thread overview]
Message-ID: <571120BD.7090309@citrix.com> (raw)
In-Reply-To: <5707ADA902000078000E60AA@prv-mh.provo.novell.com>

On 08/04/16 13:10, Jan Beulich wrote:
> http://lists.xen.org/archives/html/xen-devel/2016-03/msg02167.html
> (with the 1st patch having gone in already)

Apologies for the delay on this.  I now have results in.

The 64bit performance hit is within the noise (as expected) but sadly,
the performance impact of v3 on 32bit guests is even worse than previous
rounds.

From lmbench:

mmap() has an 85% latency hit.
pagefaults (on /local/scratch) gets a 78% hit.
pipe latency gets a 58% hit.
process fork()/exit() gets a 47% hit.

In each of these cases, that is about 20% worse that previous measurements.

As it currently stands, we really can't justify taking the fix in its
current form.

~Andrew

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  parent reply	other threads:[~2016-04-15 17:11 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-08 12:10 x86 patch ping Jan Beulich
2016-04-08 12:18 ` Andrew Cooper
2016-04-08 22:58   ` Jan Beulich
2016-04-15 17:11 ` Andrew Cooper [this message]
2016-04-17  8:22   ` Jan Beulich

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