Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758326Ab0GTMMz (ORCPT ); Tue, 20 Jul 2010 08:12:55 -0400 Received: from mailhost4.gawab.com ([66.220.20.4]:50340 "HELO info9.gawab.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752160Ab0GTMMw (ORCPT ); Tue, 20 Jul 2010 08:12:52 -0400 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Tue, 20 Jul 2010 08:12:52 EDT X-Trusted: Whitelisted From: Al Boldi To: linux-kernel@vger.kernel.org Subject: [Regression] mm: Huge swapout performance regression on recent kernels Date: Tue, 20 Jul 2010 15:07:31 +0300 User-Agent: KMail/1.5 MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201007201507.31851.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 707 Lines: 25 I have noticed a big swapout performance regression on recent kernels using the following testcase: swapon /dev/md0 (raid0) mount none /dev/shm -t tmpfs -o size=10G cat /dev/full > /dev/shm/tst.dmp Kernel starts to swapout at full speed after filling physical ram. Then, kernel progressively slows down swapout after crossing the ~3G VM threshold, compounding at over 50% slowdown when reaching the 10G tmpfs limit. Has this been fixed? Thanks! -- Al -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/