From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 7F89F6B01EF for ; Mon, 26 Apr 2010 18:34:08 -0400 (EDT) Date: Mon, 26 Apr 2010 15:33:33 -0700 From: Andrew Morton Subject: Re: swapping when there's a free memory Message-Id: <20100426153333.93c03e98.akpm@linux-foundation.org> In-Reply-To: <20100425071349.GA1275@ucw.cz> References: <20100425071349.GA1275@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Pavel Machek Cc: Mikulas Patocka , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Sun, 25 Apr 2010 09:13:49 +0200 Pavel Machek wrote: > Hi! > > > I captured this output of vmstat. The machine was freeing cache and > > swapping out pages even when there was a plenty of free memory. > > > > The machine is sparc64 with 1GB RAM with 2.6.34-rc4. This abnormal > > swapping happened during running spadfsck --- a fsck program for a custom > > filesystem that caches most reads in its internal cache --- so it reads > > buffers and allocates memory at the same time. > > > > Note that sparc64 doesn't have any low/high memory zones, so it couldn't > > be explained by filling one zone and needing to allocate pages in it. > > Fragmented memory + high-order allocation? Yeah, could be. I wonder which slab/slub/slob implementation you're using, and what page sizes it uses for dentries, inodes, etc. Can you have a poke in /prob/slabinfo? > > This abnormal behavior doesn't happen everytime, it happend about twice > > for many spadfsck attempts. > > ...yep, that would be random. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org