From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753622AbZBRAZk (ORCPT ); Tue, 17 Feb 2009 19:25:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751422AbZBRAZb (ORCPT ); Tue, 17 Feb 2009 19:25:31 -0500 Received: from mail.zelnet.ru ([80.92.97.13]:60284 "EHLO mail.zelnet.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751454AbZBRAZa (ORCPT ); Tue, 17 Feb 2009 19:25:30 -0500 Message-ID: <499B55A8.50103@gmail.com> Date: Wed, 18 Feb 2009 03:26:16 +0300 From: Edward Shishkin User-Agent: Thunderbird 2.0.0.6 (X11/20070801) MIME-Version: 1.0 To: Andrew Morton CC: peterz@infradead.org, npiggin@suse.de, rmh3093@gmail.com, randy.dunlap@oracle.com, linux-kernel@vger.kernel.org, reiserfs-devel@vger.kernel.org Subject: Re: [patch 2/4] vfs: add set_page_dirty_notag References: <18837.24581.181196.569183@edward.zelnet.ru> <1234530519.6519.46.camel@twins> <49957C43.7050701@gmail.com> <1234534150.6519.101.camel@twins> <18838.49922.215481.399653@edward.zelnet.ru> <1234645893.4695.8.camel@laptop> <18841.60432.329341.514726@edward.zelnet.ru> <20090217143506.f6899342.akpm@linux-foundation.org> In-Reply-To: <20090217143506.f6899342.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > On Tue, 17 Feb 2009 01:43:28 +0300 > Edward Shishkin wrote: > > >> + */ >> +int set_page_dirty_notag(struct page *page) >> +{ >> + struct address_space *mapping = page->mapping; >> + >> + if (!TestSetPageDirty(page)) { >> + WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page)); >> + if (mapping_cap_account_dirty(mapping)) { >> + /* >> + * The accounting functions rely on >> + * being atomic wrt interrupts. >> + */ >> + unsigned long flags; >> + local_irq_save(flags); >> + __inc_zone_page_state(page, NR_FILE_DIRTY); >> + __inc_bdi_stat(mapping->backing_dev_info, >> + BDI_RECLAIMABLE); >> + task_dirty_inc(current); >> + task_io_account_write(PAGE_CACHE_SIZE); >> + local_irq_restore(flags); >> + } >> + __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); >> + return 1; >> + } >> + return 0; >> +} >> > > I'll maintain this in -mm, alongside the resier4 patches which need it. > > Of course, this rather obviates the purpose - if someone changes, say, > __set_page_dirty_nobuffers() then they won't similarly update > set_page_dirty_notag(). Oh well. > > This problem would fix itself if those two functions were to > substantially share code. It will fix the problem only partially: there is one more friend __set_page_dirty() in buffer.c Maybe it makes sense to add comments with warnings in all such places, or create a header file with a static inline function update_page_accounting() ? > And I think we can do that - something like > > static void > update_page_accounting(struct page *page, struct address_space *mapping) > { > __inc_zone_page_state(page, NR_FILE_DIRTY); > __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE); > task_dirty_inc(current); > task_io_account_write(PAGE_CACHE_SIZE); > } > > maybe? > > We could do that as a separate patch and merge it into mainline - it > should have zero impact on code generation if gcc does the right thing > (please check this). > > >