From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: SSD slowdown with 3.3.X? Date: Wed, 18 Apr 2012 23:13:48 -0400 Message-ID: <4F8F82EC.1060708@teksavvy.com> References: <4F8F7533.6020300@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from ironport-out.teksavvy.com ([206.248.143.162]:27855 "EHLO ironport-out.teksavvy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751235Ab2DSDNu (ORCPT ); Wed, 18 Apr 2012 23:13:50 -0400 In-Reply-To: <4F8F7533.6020300@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Joe Ceklosky Cc: linux-ide@vger.kernel.org On 12-04-18 10:15 PM, Joe Ceklosky wrote: > All, > > Has anyone reported slowness using SSD's on kernel 3.3.X compiled > as 32-bit PAE with 16 Gigs of memory (I know I need to update to 64-bit > already, will do with Fedora 17)? > > I am see terrible r/w to an SSD using 3.3.2. When I boot the same machine > and SSD back in 3.2.15 all is fine. Double check which IO-scheduler the kernel is choosing. For SSDs, it is normally "noop", but I noticed "cfq" being chosen instead for some reason. find /sys -name scheduler|grep '/sd[a-z]/'|xargs cat -ml