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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 006E2C35E15 for ; Tue, 25 Feb 2020 21:48:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AEDCE20675 for ; Tue, 25 Feb 2020 21:48:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="D9msPfR5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AEDCE20675 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6B5DC6B0007; Tue, 25 Feb 2020 16:48:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 542406B0005; Tue, 25 Feb 2020 16:48:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2AF2B6B000E; Tue, 25 Feb 2020 16:48:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0059.hostedemail.com [216.40.44.59]) by kanga.kvack.org (Postfix) with ESMTP id DA1CB6B0005 for ; Tue, 25 Feb 2020 16:48:44 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 8AE34181AC9C6 for ; Tue, 25 Feb 2020 21:48:44 +0000 (UTC) X-FDA: 76529989368.05.tax24_2f2cc386cd90b X-HE-Tag: tax24_2f2cc386cd90b X-Filterd-Recvd-Size: 3754 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf07.hostedemail.com (Postfix) with ESMTP for ; Tue, 25 Feb 2020 21:48:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=w0+748cvV8fqYYK5S7voSb7ryQvDDane/jjiQr++miE=; b=D9msPfR51FpFSkZ4yp+PvhVq9v /8p2vUtvBmnkH+0U7AiCEitHwnmrbb0Cj2wMmeOctMytUSo4X8ujdyuUBoovpMt7WuBwa4WMXaCT8 lJYnZPkuWdxmkK/iIMi7H5gcLcYFemoFXyY3kyyRIM1Dn5pufEjmUJ9gQzULSpxpUh9x+yBzTL4Jf yV+nMQ8Kaq8SvlJoXbw4pKqlkmvjaLOIai5s31f+Zaep5jzhTbikbpl+vVWFQfvcBOyaX7nFC6OKq LIYbX1na3KxvUbHt1FIQ8CiO9Y5QC71++xY8kJhJLpHWtXqhLwOs7fPhZiAAHIz25pHh4LMEgvCfS jmQam+xg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6i4H-0007pz-AT; Tue, 25 Feb 2020 21:48:41 +0000 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, ocfs2-devel@oss.oracle.com, linux-xfs@vger.kernel.org, John Hubbard Subject: [PATCH v8 12/25] mm: Move end_index check out of readahead loop Date: Tue, 25 Feb 2020 13:48:25 -0800 Message-Id: <20200225214838.30017-13-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200225214838.30017-1-willy@infradead.org> References: <20200225214838.30017-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: From: "Matthew Wilcox (Oracle)" By reducing nr_to_read, we can eliminate this check from inside the loop. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: John Hubbard --- mm/readahead.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index d01531ef9f3c..a37b68f66233 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -167,8 +167,6 @@ void __do_page_cache_readahead(struct address_space *= mapping, unsigned long lookahead_size) { struct inode *inode =3D mapping->host; - struct page *page; - unsigned long end_index; /* The last page we want to read */ LIST_HEAD(page_pool); loff_t isize =3D i_size_read(inode); gfp_t gfp_mask =3D readahead_gfp_mask(mapping); @@ -178,22 +176,29 @@ void __do_page_cache_readahead(struct address_space= *mapping, ._index =3D index, }; unsigned long i; + pgoff_t end_index; /* The last page we want to read */ =20 if (isize =3D=3D 0) return; =20 - end_index =3D ((isize - 1) >> PAGE_SHIFT); + end_index =3D (isize - 1) >> PAGE_SHIFT; + if (index > end_index) + return; + /* Avoid wrapping to the beginning of the file */ + if (index + nr_to_read < index) + nr_to_read =3D ULONG_MAX - index + 1; + /* Don't read past the page containing the last byte of the file */ + if (index + nr_to_read >=3D end_index) + nr_to_read =3D end_index - index + 1; =20 /* * Preallocate as many pages as we will need. */ for (i =3D 0; i < nr_to_read; i++) { - if (index + i > end_index) - break; + struct page *page =3D xa_load(&mapping->i_pages, index + i); =20 BUG_ON(index + i !=3D rac._index + rac._nr_pages); =20 - page =3D xa_load(&mapping->i_pages, index + i); if (page && !xa_is_value(page)) { /* * Page already present? Kick off the current batch of --=20 2.25.0