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 A26D8C4741F for ; Wed, 30 Sep 2020 17:08:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C5D92087D for ; Wed, 30 Sep 2020 17:08:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731131AbgI3RIL (ORCPT ); Wed, 30 Sep 2020 13:08:11 -0400 Received: from mx2.suse.de ([195.135.220.15]:58010 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725355AbgI3RIK (ORCPT ); Wed, 30 Sep 2020 13:08:10 -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 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) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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