From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id BBDC26B0071 for ; Wed, 24 Nov 2010 12:46:30 -0500 (EST) Received: by yxl31 with SMTP id 31so3149047yxl.14 for ; Wed, 24 Nov 2010 09:46:29 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <20101122161158.02699d10.akpm@linux-foundation.org> <1290501502.2390.7029.camel@nimitz> <1290529171.2390.7994.camel@nimitz> Date: Wed, 24 Nov 2010 19:46:28 +0200 Message-ID: Subject: Re: Sudden and massive page cache eviction From: Pekka Enberg Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: =?ISO-8859-1?Q?Peter_Sch=FCller?= Cc: Dave Hansen , Andrew Morton , linux-kernel@vger.kernel.org, Mattias de Zalenski , linux-mm@kvack.org List-ID: Hi Peter, 2010/11/24 Peter Sch=FCller : >>> I forgot to address the second part of this question: How would I best >>> inspect whether the kernel is doing that? >> >> You can, for example, record >> >> =A0cat /proc/meminfo | grep Huge >> >> for large page allocations. > > Those show zero a per my other post. However I got the impression Dave > was asking about regular but larger-than-one-page allocations internal > to the kernel, while the Huge* lines in /proc/meminfo refers to > allocations specifically done by userland applications doing huge page > allocation on a system with huge pages enabled - or am I confused? He was asking about both (large page allocations and higher order allocatio= ns). >> The "pagesperslab" column of /proc/slabinfo tells you how many pages >> slab allocates from the page allocator. > > Seems to be what vmstat -m reports. No, "vmstat -m" reports _total number_ of pages allocated. We're interested in how many pages slab allocator whenever it needs to allocate memory for a new slab. That's represented by the "pagesperslab" column of /proc/slabinfo from which you can deduce the page allocation order. Pekka -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org