From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jaya Kumar" Subject: Re: [PATCH 1/1 2.6.25] fbdev: bugfix for multiprocess defio Date: Tue, 8 Jul 2008 08:50:30 -0400 Message-ID: <45a44e480807080550r65b3c5a2me3dce82629e44ccb@mail.gmail.com> References: <20080428020140.8662.66707.sendpatchset@hit-nxdomain.opendns.com> <20080430133759.e39bf34c.akpm@linux-foundation.org> <45a44e480805050023h68cffe15h5e309707ec6d8380@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1KGCeP-0004Sq-9I for linux-fbdev-devel@lists.sourceforge.net; Tue, 08 Jul 2008 05:50:33 -0700 Received: from nf-out-0910.google.com ([64.233.182.189]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1KGCeO-0003so-O9 for linux-fbdev-devel@lists.sourceforge.net; Tue, 08 Jul 2008 05:50:33 -0700 Received: by nf-out-0910.google.com with SMTP id g16so692772nfd.2 for ; Tue, 08 Jul 2008 05:50:31 -0700 (PDT) In-Reply-To: <45a44e480805050023h68cffe15h5e309707ec6d8380@mail.gmail.com> Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: Andrew Morton Cc: bernard@largestprime.net, linux-fbdev-devel@lists.sourceforge.net, Markus Armbruster On Mon, May 5, 2008 at 3:23 AM, Jaya Kumar wrote: > On Wed, Apr 30, 2008 at 1:37 PM, Andrew Morton > wrote: >> >> On Sun, 27 Apr 2008 22:01:40 -0400 >> Jaya Kumar wrote: >> >> > + /* we loop through the pagelist before adding in order >> > + to keep the pagelist sorted */ >> > + list_for_each_entry(cur, &fbdefio->pagelist, lru) { >> >> Did you consider using !list_empty(&page->lru) to avoid the linear search? >> > > Ah, no, I didn't think of that. I agree that checking list_empty would > be far better. I'll redo the patch using that. > > Thanks, > jaya > Hi Andrew, I encountered some complexity when trying to use page->lru because its not empty on its first mkwrite. I think there are probably deeper issues that repurposing page->lru for use in defio causes. I'm working on it. In the meantime, it turns out that suspend/resume of xen pvfb is affected by the same bug that raised this patch. Markus suggested, http://marc.info/?l=linux-kernel&m=121368814027583&w=2 , that perhaps this existing patch could be merged in the interim while a better solution is worked on. Would you be okay with adding this patch back into the queue? If so, should I repost it here? Thanks, jaya ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08