From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760923AbYBFV65 (ORCPT ); Wed, 6 Feb 2008 16:58:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756209AbYBFV6q (ORCPT ); Wed, 6 Feb 2008 16:58:46 -0500 Received: from extu-mxob-1.symantec.com ([216.10.194.28]:47436 "EHLO extu-mxob-1.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754495AbYBFV6p (ORCPT ); Wed, 6 Feb 2008 16:58:45 -0500 Date: Wed, 6 Feb 2008 21:58:24 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@blonde.site To: "H. Peter Anvin" cc: Tomasz Chmielewski , LKML , Mika Lawando Subject: Re: What is the limit size of tmpfs /dev/shm ? In-Reply-To: <47AA102F.1070105@zytor.com> Message-ID: References: <47A9CA0E.3030507@wpkg.org> <47AA0A2E.30701@zytor.com> <47AA102F.1070105@zytor.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 6 Feb 2008, H. Peter Anvin wrote: > > That sounds like a problem in our overall swap handling, not specifically in > tmpfs. Now, I can't say anything concrete about heavy swap conditions, but in > light swap conditions I have measured a 20x performance improvement(!) over > ext3 on real workloads. Wow, I'm surprised. I suppose I do jump to thinking of heavy swapping when light swapping won't be so bad; but even so, 20x ext3 astonishes me - ext3 wouldn't be anyone's choice for fastest, but even so... I certainly guess too much and measure too little: is there a useful test you could point me to? TIA Hugh