From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88194C433E1 for ; Fri, 21 Aug 2020 15:54:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CE46207BB for ; Fri, 21 Aug 2020 15:54:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727889AbgHUPx6 (ORCPT ); Fri, 21 Aug 2020 11:53:58 -0400 Received: from mx2.suse.de ([195.135.220.15]:56492 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726542AbgHUPxw (ORCPT ); Fri, 21 Aug 2020 11:53:52 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C0183AC65; Fri, 21 Aug 2020 15:54:19 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 7DD391E1312; Fri, 21 Aug 2020 17:53:51 +0200 (CEST) Date: Fri, 21 Aug 2020 17:53:51 +0200 From: Jan Kara To: "Matthew Wilcox (Oracle)" Cc: linux-mm@kvack.org, Andrew Morton , Hugh Dickins , William Kucharski , Johannes Weiner , Jan Kara , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/7] mm: Use pagevec_lookup in shmem_unlock_mapping Message-ID: <20200821155351.GD3432@quack2.suse.cz> References: <20200819150555.31669-1-willy@infradead.org> <20200819150555.31669-2-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200819150555.31669-2-willy@infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 19-08-20 16:05:49, Matthew Wilcox (Oracle) wrote: > The comment shows that the reason for using find_get_entries() is now > stale; find_get_pages() will not return 0 if it hits a consecutive run > of swap entries, and I don't believe it has since 2011. pagevec_lookup() > is a simpler function to use than find_get_pages(), so use it instead. > > Signed-off-by: Matthew Wilcox (Oracle) This looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > mm/shmem.c | 11 +---------- > 1 file changed, 1 insertion(+), 10 deletions(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 271548ca20f3..a7bbc4ed9677 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -840,7 +840,6 @@ unsigned long shmem_swap_usage(struct vm_area_struct *vma) > void shmem_unlock_mapping(struct address_space *mapping) > { > struct pagevec pvec; > - pgoff_t indices[PAGEVEC_SIZE]; > pgoff_t index = 0; > > pagevec_init(&pvec); > @@ -848,16 +847,8 @@ void shmem_unlock_mapping(struct address_space *mapping) > * Minor point, but we might as well stop if someone else SHM_LOCKs it. > */ > while (!mapping_unevictable(mapping)) { > - /* > - * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it > - * has finished, if it hits a row of PAGEVEC_SIZE swap entries. > - */ > - pvec.nr = find_get_entries(mapping, index, > - PAGEVEC_SIZE, pvec.pages, indices); > - if (!pvec.nr) > + if (!pagevec_lookup(&pvec, mapping, &index)) > break; > - index = indices[pvec.nr - 1] + 1; > - pagevec_remove_exceptionals(&pvec); > check_move_unevictable_pages(&pvec); > pagevec_release(&pvec); > cond_resched(); > -- > 2.28.0 > -- Jan Kara SUSE Labs, CR