From: Greg Freemyer Subject: Re: Ext4 performance regression: Post 2.6.30 Date: Mon, 29 Mar 2010 11:10:55 -0400 Message-ID: <87f94c371003290810u58f64ce6uc20be6bbac420e73@mail.gmail.com> References: <1269843935.13369.52.camel@keith-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-ext4 To: Keith Mannthey Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:61589 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751357Ab0C2PK7 (ORCPT ); Mon, 29 Mar 2010 11:10:59 -0400 Received: by gyg13 with SMTP id 13so1489513gyg.19 for ; Mon, 29 Mar 2010 08:10:58 -0700 (PDT) In-Reply-To: <1269843935.13369.52.camel@keith-laptop> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Mar 29, 2010 at 2:25 AM, Keith Mannthey wrote: > > > After 2.6.30 I am seeing large performance regressions on a raid setup. > I am working to publish a larger amount of data but I wanted to get some > quick data out about what I am seeing. > Is mdraid involved? They added barrier support for some configs after 2.6.30 I believe. It can cause a drastic perf change, but it increases reliability and is "correct". Greg