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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 075E8C4361B for ; Wed, 9 Dec 2020 12:06:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5F8223B7B for ; Wed, 9 Dec 2020 12:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731303AbgLIMGP (ORCPT ); Wed, 9 Dec 2020 07:06:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730288AbgLIMGP (ORCPT ); Wed, 9 Dec 2020 07:06:15 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F586C0613CF; Wed, 9 Dec 2020 04:05:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5t3oRIaMaC7qwxPcnQux4DtmClUR9K6n75chtZH1BU8=; b=r230O62V7u7Rvgpd0cKLkyUe/K ovgQEIRHQd25C33Hkol6I1brBUpaAkemNlaW4op2WydoJnRBR084yBBLWvZkhvyayt4Vq22XMaEFl RnU/IeR9cfCar5LMYh4EmWJeA4n5IOEaJNFJQuMwuEtBUxINsJ65qwaAT9TddHoEG7qN0JGkX2PUn wATz+ejr+lUQkk1NvRbK9PDMW2Z7RWhz2V3i6W0SL8kN4Oh6tdRiSosswUlRIzLRZBvILKMyq4bLM nrqXAyianz2SxmwVfN9PVqznp2wlEIDgya+2l1nGrxYTswq32+IY3LJGS2ZBthrYpM++bIsC4qJIj 4GQNTdIA==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmyDr-0002nL-Gw; Wed, 09 Dec 2020 12:05:31 +0000 Date: Wed, 9 Dec 2020 12:05:31 +0000 From: Christoph Hellwig To: Pavel Begunkov Cc: Christoph Hellwig , Jens Axboe , Alexander Viro , linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox , Johannes Weiner , Ming Lei Subject: Re: [PATCH 2/2] block: no-copy bvec for direct IO Message-ID: <20201209120531.GA9598@infradead.org> References: <51905c4fcb222e14a1d5cb676364c1b4f177f582.1607477897.git.asml.silence@gmail.com> <20201209084005.GC21968@infradead.org> <63057f61-85e5-4720-3532-1a1ba05ab41a@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <63057f61-85e5-4720-3532-1a1ba05ab41a@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Dec 09, 2020 at 12:01:27PM +0000, Pavel Begunkov wrote: > On 09/12/2020 08:40, Christoph Hellwig wrote: > >> + /* > >> + * In practice groups of pages tend to be accessed/reclaimed/refaulted > >> + * together. To not go over bvec for those who didn't set BIO_WORKINGSET > >> + * approximate it by looking at the first page and inducing it to the > >> + * whole bio > >> + */ > >> + if (unlikely(PageWorkingset(iter->bvec->bv_page))) > >> + bio_set_flag(bio, BIO_WORKINGSET); > > > > IIRC the feedback was that we do not need to deal with BIO_WORKINGSET > > at all for direct I/O. > > I was waiting for the conversation to unfold, i.e. for Johannes to > answer. BTW, would the same (skipping BIO_WORKINGSET) stand true for > iomap? iomap direct I/O: yes.