From: "John Stoffel" <john@stoffel.org>
To: Christoph Lameter <cl@linux.com>
Cc: John Stoffel <john@stoffel.org>,
KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Rik van Riel <riel@redhat.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, Mel Gorman <mel@csn.ul.ie>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH -mm] make swapin readahead skip over holes
Date: Wed, 11 Jan 2012 16:03:54 -0500 [thread overview]
Message-ID: <20237.63802.982209.699996@quad.stoffel.home> (raw)
In-Reply-To: <alpine.DEB.2.00.1201111305440.31239@router.home>
>>>>> "Christoph" == Christoph Lameter <cl@linux.com> writes:
Christoph> On Wed, 11 Jan 2012, John Stoffel wrote:
KOSAKI> so, we can eat free lunch up to 7MB ~= 60(MB/sec) * 1000 / 8.5(ms).
>>
>> What if the disk is busy doing other writeout or readin during this
>> time? You can't assume you have the full disk bandwidth available,
>> esp when you hit a swap storm like this.
Christoph> The assumptions by Kosaki are quite conservative.
Just checking
Christoph> What if one did not get a disk from the garbage heap but
Christoph> instead has a state of the art storage cluster or simply an
Christoph> SSD (in particular relevant now since HDs are in short
Christoph> supply given the situation in Asia)?
I don't know, I was just trying to make sure he thinks about disks
which are slower than he expects, since there are lots of them still
out there.
John
next prev parent reply other threads:[~2012-01-11 21:04 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-09 23:10 [PATCH -mm] make swapin readahead skip over holes Rik van Riel
2012-01-09 23:49 ` KOSAKI Motohiro
2012-01-10 3:09 ` Rik van Riel
2012-01-11 7:14 ` KOSAKI Motohiro
2012-01-11 8:01 ` KOSAKI Motohiro
2012-01-11 8:05 ` KOSAKI Motohiro
2012-01-11 14:11 ` John Stoffel
2012-01-11 19:17 ` Christoph Lameter
2012-01-11 21:03 ` John Stoffel [this message]
2012-01-11 22:25 ` KOSAKI Motohiro
2012-01-11 23:15 ` Andrew Morton
2012-01-11 16:51 ` Mel Gorman
2012-01-11 19:23 ` Rik van Riel
2012-01-12 14:33 ` Mel Gorman
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