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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5CD9C54EBD for ; Sat, 7 Jan 2023 15:11:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D8B6C8E0002; Sat, 7 Jan 2023 10:11:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D13EE8E0001; Sat, 7 Jan 2023 10:11:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BDC3A8E0002; Sat, 7 Jan 2023 10:11:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id AE5E98E0001 for ; Sat, 7 Jan 2023 10:11:54 -0500 (EST) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 8C3B71C5CC7 for ; Sat, 7 Jan 2023 15:11:54 +0000 (UTC) X-FDA: 80328342948.26.54C8A3A Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf04.hostedemail.com (Postfix) with ESMTP id 1D82D40013 for ; Sat, 7 Jan 2023 15:11:51 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=ZNxGrxfY; dmarc=none; spf=none (imf04.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1673104312; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=cq3Tcm7OLVA1me+kKR9zka8dfFlwNGfvdQ54sCCOFy0=; b=H9HEIuJv1noevGTwxZGGiB5DN2rOs7KLiG262vVti3siWW5PaeX4z5vsMtcIQ0Y5FqleBU /vvvgAuAh6YrblTCqOJy9KKH3aVI8FTrQyiBZesDkTVxB7qOH+ppgUikokB6g/Be7WK7jM sWR7HiIIxl+Pz8+jdOGksEKGw7+DvZg= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=ZNxGrxfY; dmarc=none; spf=none (imf04.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1673104312; a=rsa-sha256; cv=none; b=iPEICM0g9prJaHdYSanAzWuG5JVQ3h2lSurKsaIKK8zKTHVvYZn6GjZne4V9Uqc/2VTz25 CMogVzJM2cjWqG+JtQUfbcADyE+JHHhHTZ4iuJyaq5WlHtS7hcnFk/tgcCcsG95AK8vhck LW7CTs+AzioZl9cBGxtf31yy3nuMfWg= 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=cq3Tcm7OLVA1me+kKR9zka8dfFlwNGfvdQ54sCCOFy0=; b=ZNxGrxfYZ18g+iYGTFB+S1ko54 lj1sxWXhAn78Z3mSPVR2VNhutJKCAxFaz7EvlYN14xY1q6+NBT5BmqFVf/nJJRXx3rkyJLyzNsotg p2AncToaCGxm00OtMsKBilhhcwdZaLAT92+SGg+aiYltEWGvShClAy8z/ZR/bi7VI7vE5J+bt26Am gl2QLP2YD9kfgP/iz1ffl1HiLzGCokiMepgI+S3Woob+xpPYF/t/jYpqc9CydIc1SEn5K9QJfINJB 3kqKLKrmueMObbikddZ9gvcsiGZattD6U4HvI2cIcSbuPAQJI15Mvcrjjs0mZKc3oACChoxW3lSC/ 5B9rSMTQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pEArM-000dly-Pt; Sat, 07 Jan 2023 15:11:48 +0000 Date: Sat, 7 Jan 2023 15:11:48 +0000 From: Matthew Wilcox To: David Howells Cc: Rohith Surabattula , Linus Torvalds , Steve French , Shyam Prasad N , Dave Wysochanski , Dominique Martinet , Ilya Dryomov , Theodore Ts'o , Andreas Dilger , linux-cachefs@redhat.com, linux-cifs@vger.kernel.org, linux-afs@lists.infradead.org, v9fs-developer@lists.sourceforge.net, ceph-devel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Jeff Layton , linux-erofs@lists.ozlabs.org, linux-ext4@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/3] mm: Merge folio_has_private()/filemap_release_folio() call pairs Message-ID: References: <167172131368.2334525.8569808925687731937.stgit@warthog.procyon.org.uk> <167172132272.2334525.13617516784050484518.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <167172132272.2334525.13617516784050484518.stgit@warthog.procyon.org.uk> X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 1D82D40013 X-Stat-Signature: a8o9o3wmuxpzzj1qjxfx7ex3d863yzja X-HE-Tag: 1673104311-451677 X-HE-Meta: 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 A5GBWJZo SR3Hm 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 Thu, Dec 22, 2022 at 03:02:02PM +0000, David Howells wrote: > Make filemap_release_folio() check folio_has_private(). Then, in most > cases, where a call to folio_has_private() is immediately followed by a > call to filemap_release_folio(), we can get rid of the test in the pair. > > The same is done to page_has_private()/try_to_release_page() call pairs. This line is now obsolete. > There are a couple of sites in mm/vscan.c that this can't so easily be > done. In shrink_folio_list(), there are actually three cases (something > different is done for incompletely invalidated buffers), but > filemap_release_folio() elides two of them. > > In shrink_active_list(), we don't have have the folio lock yet, so the > check allows us to avoid locking the page unnecessarily. > > A wrapper function to check if a folio needs release is provided for those > places that still need to do it in the mm/ directory. This will acquire > additional parts to the condition in a future patch. > > After this, the only remaining caller of folio_has_private() outside of mm/ > is a check in fuse. But there are a few remaining places which check page_has_private(). I think they're all wrong and should be PagePrivate(), but I'll look at them more next week.