Message-ID: <4D63EC77.6070208@mnsu.edu>
Date: Tue, 22 Feb 2011 11:03:51 -0600
From: Jeffrey Hundstad <jeffrey.hundstad@mnsu.edu>
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To: Andrea Arcangeli <aarcange@redhat.com>
CC: Minchan Kim <minchan.kim@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
        Steven Barrett <damentz@liquorix.net>,
        Ben Gamari <bgamari.foss@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>, Rik van Riel <riel@redhat.com>,
        Mel Gorman <mel@csn.ul.ie>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Wu Fengguang <fengguang.wu@intel.com>,
        Johannes Weiner <hannes@cmpxchg.org>, Nick Piggin <npiggin@kernel.dk>,
        Balbir Singh <balbir@linux.vnet.ibm.com>,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Subject: Re: [PATCH v6 0/4] fadvise(DONTNEED) support
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On 02/22/2011 07:28 AM, Andrea Arcangeli wrote:
> Hi Minchan,
> That's my point, we should check if the "thrashing horribly" is really
> a "recently" or if it has always happened before with 2.6.18 and previous.

I would bet that "thrashing" isn't what he meant.  He almost certainly 
meant "needless I/O" and nothing to do with swapping.  I've seen this 
similar report before.  This report is almost always gets answered with 
a "set your swappiness to an appropriate value" type answer.  Or a "your 
userspace app needs to get smarter" type answer.  I think they are 
trying to do the latter, but need some help from the kernel, and that's 
what they're trying to do here.

-- 
Jeffrey Hundstad

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