From: Marcelo Tosatti <mtosatti@redhat.com>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>,
balbir@linux.vnet.ibm.com, jdike@addtoit.com,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
avi@redhat.com
Subject: Re: [PATCH] emulate accessed bit for EPT
Date: Fri, 5 Feb 2010 15:34:23 -0200 [thread overview]
Message-ID: <20100205173422.GA14706@amt.cnet> (raw)
In-Reply-To: <20100204174715.GL5959@random.random>
On Thu, Feb 04, 2010 at 06:47:15PM +0100, Andrea Arcangeli wrote:
> On Thu, Feb 04, 2010 at 08:40:43AM -0500, Rik van Riel wrote:
> > I suspect it won't be very many. I have been monitoring
> > /proc/meminfo on my system while testing this patch, and
> > it is quite typical that the size of the inactive anon
> > list does not change for minutes at a time.
> >
> > In other words, no pages are moved onto or off of the
> > inactive anon list for several minutes. That corresponds
> > to a very small number of minor faults introduced by my
> > patch.
>
> When there's light VM pressure, ideally there should be zero overhead
> caused by the patch. When there is VM pressure this will avoid some
> unnecessary I/O which should outweight the minor faults. It should be
> a good default behavior.
Agree.
But perhaps a module parameter to turn accessed bit emulation off might
be handy in the future?
next prev parent reply other threads:[~2010-02-05 17:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-03 21:11 [PATCH] emulate accessed bit for EPT Rik van Riel
2010-02-04 4:12 ` Balbir Singh
2010-02-04 13:40 ` Rik van Riel
2010-02-04 15:30 ` Balbir Singh
2010-02-04 15:41 ` Rik van Riel
2010-02-04 15:52 ` Balbir Singh
2010-02-04 17:47 ` Andrea Arcangeli
2010-02-05 17:34 ` Marcelo Tosatti [this message]
2010-02-05 18:14 ` Andrea Arcangeli
2010-02-07 19:21 ` Marcelo Tosatti
2010-02-04 16:17 ` Jeff Dike
2010-02-08 10:27 ` Avi Kivity
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