From: Tejun Heo Subject: Re: [PATCH 1/4] sched: move IO scheduling accounting from io_schedule_timeout() to __schedule() Date: Tue, 6 Dec 2016 16:30:32 -0500 Message-ID: <20161206213032.GC26314@mtj.duckdns.org> References: <1477673892-28940-1-git-send-email-tj@kernel.org> <1477673892-28940-2-git-send-email-tj@kernel.org> <20161028182712.GM3142@twins.programming.kicks-ass.net> <20161028190702.GL3157@twins.programming.kicks-ass.net> <20161028191231.GA29044@htj.duckdns.org> <20161029032126.GH3568@worktop.programming.kicks-ass.net> <20161031164556.GC26364@mtj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Tejun Heo , torvalds@linux-foundation.org, akpm@linux-foundation.org, mingo@redhat.com, axboe@kernel.dk, tytso@mit.edu, jack@suse.com, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, mingbo@fb.com To: Peter Zijlstra Return-path: Content-Disposition: inline In-Reply-To: <20161031164556.GC26364@mtj.duckdns.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hello, On Mon, Oct 31, 2016 at 10:45:56AM -0600, Tejun Heo wrote: > Tracking the owners of mutexes and rwsems does help quite a bit. I > don't think it's as simple as inheriting io sleep state from the > current owner tho. The owner might be running or in a non-IO sleep > when others try to grab the mutex. It is an option to ignore those > cases but this would have a real possibility to lead to surprising > results in some corner cases. If we choose to propagate dynamically, > it becomes an a lot more complex problem and I don't think it'd be > justfiable. > > Unless there can be a simple enough and reliable solution, I think > it'd be better to stick with explicit marking. Just posted the fixed version for the first patch. Any more thoughts on this? Thanks. -- tejun