From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 253376B00B8 for ; Mon, 3 Jan 2011 17:03:41 -0500 (EST) Received: from kpbe13.cbf.corp.google.com (kpbe13.cbf.corp.google.com [172.25.105.77]) by smtp-out.google.com with ESMTP id p03M3ZMM001023 for ; Mon, 3 Jan 2011 14:03:38 -0800 Received: from pwj10 (pwj10.prod.google.com [10.241.219.74]) by kpbe13.cbf.corp.google.com with ESMTP id p03M3YL6022302 for ; Mon, 3 Jan 2011 14:03:34 -0800 Received: by pwj10 with SMTP id 10so1781695pwj.16 for ; Mon, 03 Jan 2011 14:03:34 -0800 (PST) Date: Mon, 3 Jan 2011 14:03:31 -0800 (PST) From: David Rientjes Subject: Re: [PATCH] writeback: avoid unnecessary determine_dirtyable_memory call In-Reply-To: <1294072249-2916-1-git-send-email-minchan.kim@gmail.com> Message-ID: References: <1294072249-2916-1-git-send-email-minchan.kim@gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , Wu Fengguang , Peter Zijlstra List-ID: On Tue, 4 Jan 2011, Minchan Kim wrote: > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index fc93802..c340536 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -390,9 +390,12 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty) > { > unsigned long background; > unsigned long dirty; > - unsigned long available_memory = determine_dirtyable_memory(); > + unsigned long available_memory; You need unsigned long uninitialized_var(available_memory) to avoid the warning. > struct task_struct *tsk; > > + if (!vm_dirty_bytes || !dirty_background_bytes) > + available_memory = determine_dirtyable_memory(); > + > if (vm_dirty_bytes) > dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE); > else -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org