From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268136AbUHXB2E (ORCPT ); Mon, 23 Aug 2004 21:28:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267961AbUHXB2C (ORCPT ); Mon, 23 Aug 2004 21:28:02 -0400 Received: from fw.osdl.org ([65.172.181.6]:29418 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S268136AbUHXBXI (ORCPT ); Mon, 23 Aug 2004 21:23:08 -0400 Date: Mon, 23 Aug 2004 18:21:09 -0700 From: Andrew Morton To: Dave Jones Cc: linux-kernel@vger.kernel.org, suparna@in.ibm.com Subject: Re: [PATCH] Writeback page range hint Message-Id: <20040823182109.6af19081.akpm@osdl.org> In-Reply-To: <20040824011822.GB15668@redhat.com> References: <200408232138.i7NLcfJd019125@hera.kernel.org> <20040824010723.GA15668@redhat.com> <20040823181400.7d721370.akpm@osdl.org> <20040824011822.GB15668@redhat.com> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Jones wrote: > > On Mon, Aug 23, 2004 at 06:14:00PM -0700, Andrew Morton wrote: > > > > > + int nonblocking:1; /* Don't get stuck on request queues */ > > > > + int encountered_congestion:1; /* An output: a queue is full */ > > > > + int for_kupdate:1; /* A kupdate writeback */ > > > > + int for_reclaim:1; /* Invoked from the page allocator */ > > > > > > Causes sparse spew.. > > > > > > include/linux/writeback.h:54:19: warning: dubious one-bit signed bitfield > > > include/linux/writeback.h:55:30: warning: dubious one-bit signed bitfield > > > include/linux/writeback.h:56:19: warning: dubious one-bit signed bitfield > > > include/linux/writeback.h:57:19: warning: dubious one-bit signed bitfield > > > > That's fussy of it. I assume this shuts it up? > > very likely (its 2am, and I'm feeling too lazy to check). That's the middle of the working day. > though, is there any real reason why they are bitfields at all ? That should have been in the changelog. Bad Suparna. These structures are allocated on the stack in the (deep) writeback paths. Saving a few bytes there does seem to be worth the increased code size.