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=unavailable 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 3E05FC3403D for ; Mon, 17 Feb 2020 18:46:38 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 12E242467D; Mon, 17 Feb 2020 18:46:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sourceforge.net header.i=@sourceforge.net header.b="Qm/KBkIs"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sf.net header.i=@sf.net header.b="QbqkYwwV"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="mG3ezOVT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 12E242467D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-f2fs-devel-bounces@lists.sourceforge.net Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1j3lPh-0000Jp-O3; Mon, 17 Feb 2020 18:46:37 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1j3lPf-0000HW-MT for linux-f2fs-devel@lists.sourceforge.net; Mon, 17 Feb 2020 18:46:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; 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:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=GsjiaZugI72vbGelDXh1gHsSqzMvkN1OtgDj3kywYLo=; b=Qm/KBkIsnhGLHZkyk5yMG/ggY/ ow6Xf+AtsY5zTXH2txrCTpqRnZJhOzsO2GpYBFGnZEtlO3kjNAmTiS1TAbGKen/pF0EyOut03AFKj xWcWSDWU6HNOu4/oKpnJLTNCDRHvnyoA7ky+OLWSkRiDOU3epU7o263pd/FE2LWo+t6Q=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; 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:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=GsjiaZugI72vbGelDXh1gHsSqzMvkN1OtgDj3kywYLo=; b=QbqkYwwVGw5CbxTr0G+xmOd5Yk alpOSvT3ddMbkURGgF8jsvfS2pn42G8Jf94nsOlY08h9/ZMz4/2X6Pok6+J6r6vzTl4G0Lsjbxf91 Ao4/tbBJ3MPq1iMZ2141fR7kEdcOz9C/MfgxtOYULsAK2sisvF+MXE7BBErVEnwA/JQI=; Received: from bombadil.infradead.org ([198.137.202.133]) by sfi-mx-4.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1j3lPe-006PPG-MS for linux-f2fs-devel@lists.sourceforge.net; Mon, 17 Feb 2020 18:46:35 +0000 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=GsjiaZugI72vbGelDXh1gHsSqzMvkN1OtgDj3kywYLo=; b=mG3ezOVTlUwDZANXsCHvcKdwJB z3OlpT7AjCBCJphbep/jJMnYwWkqQCv4wTdvjax0x0CW6Nvu8+8tccy4vlbefujrJjJEj82Cnsx1d 0Z0dVex246tKQbAITwLWjKWZ5u/u/QkHJfmmheFgDcrAuXqy1jKQgdOFfs9OG8e4Jv179uA6lHT0C rj7l1UtOFC7pBjOM+uPFkUB4PEe+Mm5ggHB2nPVgYYpq1iZJM1/7wiOXsE7PHbRws4qZi4knTfp9M Abo7HX1ADfB8vHy4nwtU2Q4tJcbww1fj8NQ9P/NHWgtRpkc995sdbYd50dglXP3xbP8Qt8cWX4AgS 6OQh+pkw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j3lPL-00058r-DR; Mon, 17 Feb 2020 18:46:15 +0000 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org Date: Mon, 17 Feb 2020 10:45:45 -0800 Message-Id: <20200217184613.19668-5-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200217184613.19668-1-willy@infradead.org> References: <20200217184613.19668-1-willy@infradead.org> MIME-Version: 1.0 X-Headers-End: 1j3lPe-006PPG-MS Subject: [f2fs-dev] [PATCH v6 04/19] mm: Rearrange readahead loop X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, "Matthew Wilcox \(Oracle\)" , linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-mm@kvack.org, ocfs2-devel@oss.oracle.com, linux-ext4@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-btrfs@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net From: "Matthew Wilcox (Oracle)" Move the declaration of 'page' to inside the loop and move the 'kick off a fresh batch' code to the end of the function for easier use in subsequent patches. Signed-off-by: Matthew Wilcox (Oracle) --- mm/readahead.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index 15329309231f..3eca59c43a45 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -154,7 +154,6 @@ void __do_page_cache_readahead(struct address_space *mapping, unsigned long lookahead_size) { struct inode *inode = mapping->host; - struct page *page; unsigned long end_index; /* The last page we want to read */ LIST_HEAD(page_pool); int page_idx; @@ -175,6 +174,7 @@ void __do_page_cache_readahead(struct address_space *mapping, * Preallocate as many pages as we will need. */ for (page_idx = 0; page_idx < nr_to_read; page_idx++) { + struct page *page; pgoff_t page_offset = offset + page_idx; if (page_offset > end_index) @@ -183,14 +183,14 @@ void __do_page_cache_readahead(struct address_space *mapping, page = xa_load(&mapping->i_pages, page_offset); if (page && !xa_is_value(page)) { /* - * Page already present? Kick off the current batch of - * contiguous pages before continuing with the next - * batch. + * Page already present? Kick off the current batch + * of contiguous pages before continuing with the + * next batch. This page may be the one we would + * have intended to mark as Readahead, but we don't + * have a stable reference to this page, and it's + * not worth getting one just for that. */ - if (readahead_count(&rac)) - read_pages(&rac, &page_pool, gfp_mask); - rac._nr_pages = 0; - continue; + goto read; } page = __page_cache_alloc(gfp_mask); @@ -201,6 +201,11 @@ void __do_page_cache_readahead(struct address_space *mapping, if (page_idx == nr_to_read - lookahead_size) SetPageReadahead(page); rac._nr_pages++; + continue; +read: + if (readahead_count(&rac)) + read_pages(&rac, &page_pool, gfp_mask); + rac._nr_pages = 0; } /* -- 2.25.0 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel