From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752258AbcGODFG (ORCPT ); Thu, 14 Jul 2016 23:05:06 -0400 Received: from mail.kernel.org ([198.145.29.136]:45042 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752025AbcGODFE (ORCPT ); Thu, 14 Jul 2016 23:05:04 -0400 Date: Thu, 14 Jul 2016 20:05:02 -0700 From: Jaegeuk Kim To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [PATCH 5/5] f2fs: use blk_plug in all the possible paths Message-ID: <20160715030502.GB44979@jaegeuk> References: <20160715004629.43143-1-jaegeuk@kernel.org> <20160715004629.43143-5-jaegeuk@kernel.org> <20160715022132.GA1513@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160715022132.GA1513@infradead.org> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 14, 2016 at 07:21:32PM -0700, Christoph Hellwig wrote: > On Thu, Jul 14, 2016 at 05:46:29PM -0700, Jaegeuk Kim wrote: > > The main reason is that blk_start_plug can be used to wake up from low-power > > mode before submitting further bios. > > Where does that myth come from? >>From kernel guys working on android. And, I'm in also doubt they may have done something regarding to power mode change, by the fact that I've seen annoying performance jitters comparing to ext4's ones all the time in some android products. Frankly speaking, I cannot find a concrete reason to remove plugging entirely, since I can't see big performance differences in all my test results in severs as well. Thanks,