From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: RAID1 might_sleep() warning on 3.19-rc7 Date: Fri, 13 Feb 2015 15:48:03 +0100 Message-ID: <20150213144803.GA11574@worktop.ger.corp.intel.com> References: <20150206085133.2c1ab892@notabene.brown> <20150206113930.GK23123@twins.programming.kicks-ass.net> <20150209121357.29f19d36@notabene.brown> <20150209091000.GN5029@twins.programming.kicks-ass.net> <20150210135017.7659e49c@notabene.brown> <20150210092936.GW21418@twins.programming.kicks-ass.net> <20150213162600.059fffb2@notabene.brown> <20150213083250.GN2896@worktop.programming.kicks-ass.net> <20150213194953.0368355d@notabene.brown> <20150213102746.GO2896@worktop.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150213102746.GO2896@worktop.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org To: NeilBrown Cc: Tony Battersby , linux-raid@vger.kernel.org, lkml , axboe@kernel.dk, Linus Torvalds List-Id: linux-raid.ids On Fri, Feb 13, 2015 at 11:27:46AM +0100, Peter Zijlstra wrote: > > I've moved blk_flush_plug to the beginning of the function. > > > I wondered if it really make sense to call blk_flush_plug with nr_iowait > > elevated and delayacct_blkio active. blk_flush_plug() could call schedule() > > for non-"io" reasons and maybe that could upset stuff??? > > Yeah, good question that. Lemme ponder that a bit. Yes, I thikn your version makes most sense as, you say, even regular schedule() call nested in my version would go towards blk delayacct -- and I doubt that was the intent; even though the current kernel works that way. I'll move the now rudimentary io_schedule() into sched.h as an inline.