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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 9AF30C4727C for ; Wed, 30 Sep 2020 17:08:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0DD3920754 for ; Wed, 30 Sep 2020 17:08:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0DD3920754 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 804206B0072; Wed, 30 Sep 2020 13:08:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7DBF66B0073; Wed, 30 Sep 2020 13:08:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 719176B0074; Wed, 30 Sep 2020 13:08:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0079.hostedemail.com [216.40.44.79]) by kanga.kvack.org (Postfix) with ESMTP id 5A5546B0072 for ; Wed, 30 Sep 2020 13:08:11 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0E67E52A3 for ; Wed, 30 Sep 2020 17:08:11 +0000 (UTC) X-FDA: 77320360782.22.cat33_4c04b9927194 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id A31D618038E6B for ; Wed, 30 Sep 2020 17:08:10 +0000 (UTC) X-HE-Tag: cat33_4c04b9927194 X-Filterd-Recvd-Size: 3190 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Wed, 30 Sep 2020 17:08:10 +0000 (UTC) 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 C4774B213; Wed, 30 Sep 2020 17:08:08 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id C68FF1E0EAA; Wed, 30 Sep 2020 19:08:07 +0200 (CEST) Date: Wed, 30 Sep 2020 19:08:07 +0200 From: Jan Kara To: Matthew Wilcox Cc: Jan Kara , linux-mm@kvack.org, Andrew Morton , Hugh Dickins , William Kucharski , Johannes Weiner , Yang Shi , Dave Chinner , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 12/12] mm/filemap: Return only head pages from find_get_entries Message-ID: <20200930170807.GA15977@quack2.suse.cz> References: <20200914130042.11442-1-willy@infradead.org> <20200914130042.11442-13-willy@infradead.org> <20200930121512.GT10896@quack2.suse.cz> <20200930123637.GP20115@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200930123637.GP20115@casper.infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed 30-09-20 13:36:37, Matthew Wilcox wrote: > On Wed, Sep 30, 2020 at 02:15:12PM +0200, Jan Kara wrote: > > On Mon 14-09-20 14:00:42, Matthew Wilcox (Oracle) wrote: > > > All callers now expect head (and base) pages, and can handle multiple > > > head pages in a single batch, so make find_get_entries() behave that way. > > > Also take the opportunity to make it use the pagevec infrastructure > > > instead of open-coding how pvecs behave. This has the side-effect of > > > being able to append to a pagevec with existing contents, although we > > > don't make use of that functionality anywhere yet. > > > > > > Signed-off-by: Matthew Wilcox (Oracle) > > > > Looks good to me. You can add: > > > > Reviewed-by: Jan Kara > > > > I'm just curious: What has happened to pagevec_lookup_entries() call in > > invalidate_inode_pages2_range()? Your series appears to be based on a tree > > where the call already does not exist... > > That went away in patch 10 of this series. Ah, I see. Thanks. Then I'm somewhat wondering is really invalidate_inode_pages2_range() safe for THP head pages? At least the: unmap_mapping_pages(mapping, index, 1, false); doesn't look adequate for THP head pages... do_launder_page() is also doubtful but probably currently OK because THPs cannot be dirty at this moment. But how about THPs that are partialy inside start-end range? So far the function didn't care because it was operating on page basis so it didn't care but now it is probably relevant... At least it would warrant a comment in some changelog if you are convinced everything is safe. Honza -- Jan Kara SUSE Labs, CR