From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx177.postini.com [74.125.245.177]) by kanga.kvack.org (Postfix) with SMTP id E98A06B0044 for ; Wed, 25 Apr 2012 23:22:58 -0400 (EDT) Received: by vbbey12 with SMTP id ey12so781022vbb.14 for ; Wed, 25 Apr 2012 20:22:57 -0700 (PDT) Message-ID: <4F98BF90.9050703@gmail.com> Date: Wed, 25 Apr 2012 23:22:56 -0400 From: Joe Ceklosky MIME-Version: 1.0 Subject: Possible 32-bit PAE kernel I/O slow down with 3.3.X Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org I have notice significant slow downs with disk I/O on a 32-bit PAE 3.3.X kernels. The test machine has 16GB memory, Intel i5 CPU, Intel motherboard, and an Intel 160GB SSD. I copied 536M from one partition on an SSD to another. Test 1: kernel 3.3.2 32-bit PAE with kernel parm mem=3G time cp -ra testdir/ /tmp real 0m8.989s user 0m0.094s sys 0m1.080s Test 2: kernel 3.3.2 32-bit PAE time cp -ra testdir/ /tmp real 1m17.068s user 0m0.173s sys 0m2.149s Also I tested kernel 3.2.16 32-bit PAE with no memory limits and it was in line with test 1. Am I doing something wrong or could something have been broken in PAE with kernel 3.3.X? Thanks, Joe Ceklosky -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org