From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fengguang Wu Subject: Re: [PATCH] writeback: avoid possible balance_dirty_pages() lockup on a light-load bdi Date: Tue, 2 Oct 2007 21:27:02 +0800 Message-ID: <20071002132702.GA10967__46646.9087558382$1191331702$gmane$org@mail.ustc.edu.cn> References: <92cbf19b0709272332s25684643odaade0e98cb3a1f4@mail.gmail.com> <391063897.19256@ustc.edu.cn> <470118EE.1020103@redhat.com> <391290444.23950@ustc.edu.cn> <20071001191457.2f7c7538.akpm@linux-foundation.org> <20071002121327.GA5718@mail.ustc.edu.cn> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Message-ID: <20071002132702.GA10967@mail.ustc.edu.cn> Content-Disposition: inline In-Reply-To: <20071002121327.GA5718@mail.ustc.edu.cn> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Andrew Morton Cc: Chakri n , Peter Zijlstra , Greg KH , lkml , Chuck Ebbert , Krzysztof Oledzki , linux-pm , richard kennedy , Ingo Molnar List-Id: linux-pm@vger.kernel.org On Tue, Oct 02, 2007 at 08:13:27PM +0800, Fengguang Wu wrote: [...] > One more serious problem is, a busy writer could also drain all the > dirty pages and make (nr_writeback == dirty_limit+1MB). In that case, > I suspect the light-load sdb writer still have good chance to > make progress(need confirmation). Well it seems to be a really tricky issue without knowing the per-bdi numbers. Maybe we could just encourage users to upgrade to 2.6.24...