Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756112Ab2BCOBa (ORCPT ); Fri, 3 Feb 2012 09:01:30 -0500 Received: from mail-wi0-f174.google.com ([209.85.212.174]:62938 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754436Ab2BCOB3 convert rfc822-to-8bit (ORCPT ); Fri, 3 Feb 2012 09:01:29 -0500 MIME-Version: 1.0 In-Reply-To: <1328275948.2662.15.camel@laptop> References: <1328275626-5322-1-git-send-email-amit.sahrawat83@gmail.com> <1328275948.2662.15.camel@laptop> Date: Fri, 3 Feb 2012 19:31:27 +0530 Message-ID: Subject: Re: [PATCH 2/2] mm: make do_writepages() use plugging From: Amit Sahrawat To: Peter Zijlstra Cc: Wu Fengguang , Jan Kara , Andrew Morton , Johannes Weiner , Amit Sahrawat , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1965 Lines: 61 Hi Peter, Thanks for pointing out. While checking the plug support in Write code flow, I came across this main point from which - we invoke writepages(mapping->a_ops->writepages(mapping, wbc)) from almost all the the filesystems. By mistake I checked 2 different kernel versions for this code(and missed that the current version already has put plug in mpage_writepages) ... so may be this patch is not worth considering. Regards, Amit Sahrawat On Fri, Feb 3, 2012 at 7:02 PM, Peter Zijlstra wrote: > On Fri, 2012-02-03 at 18:57 +0530, Amit Sahrawat wrote: >> This will cover all the invocations for writepages to be called with >> plugging support. > > This changelog fails to explain why this is a good thing... I thought > the idea of the new plugging stuff was that we now don't need to > sprinkle plugs all over the kernel.. > >> Signed-off-by: Amit Sahrawat >> --- >> ?mm/page-writeback.c | ? ?4 ++++ >> ?1 files changed, 4 insertions(+), 0 deletions(-) >> >> diff --git a/mm/page-writeback.c b/mm/page-writeback.c >> index 363ba70..2bea32c 100644 >> --- a/mm/page-writeback.c >> +++ b/mm/page-writeback.c >> @@ -1866,14 +1866,18 @@ EXPORT_SYMBOL(generic_writepages); >> >> ?int do_writepages(struct address_space *mapping, struct writeback_control *wbc) >> ?{ >> + ? ? struct blk_plug plug; >> ? ? ? int ret; >> >> ? ? ? if (wbc->nr_to_write <= 0) >> ? ? ? ? ? ? ? return 0; >> + >> + ? ? blk_start_plug(&plug); >> ? ? ? if (mapping->a_ops->writepages) >> ? ? ? ? ? ? ? ret = mapping->a_ops->writepages(mapping, wbc); >> ? ? ? else >> ? ? ? ? ? ? ? ret = generic_writepages(mapping, wbc); >> + ? ? blk_finish_plug(&plug); >> ? ? ? return ret; >> ?} >> > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/