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=-9.5 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 DA7ECC11D06 for ; Wed, 19 Feb 2020 21:01:27 +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 A57972467E; Wed, 19 Feb 2020 21:01:26 +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="V1UrpUe/"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sf.net header.i=@sf.net header.b="NDqq4BXa"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Rr0Isn6K" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A57972467E 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-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1j4WTG-0002W9-Ho; Wed, 19 Feb 2020 21:01:26 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1j4WT7-0002TZ-RV for linux-f2fs-devel@lists.sourceforge.net; Wed, 19 Feb 2020 21:01:17 +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=8zYEi4IG7gzAvMHdDHY3fStOc4dh5wVqKWm99G/lD2Q=; b=V1UrpUe/qpAgLXbMzc2FGvyedt Jot4/ezqS2muNdguuHuFE6B2EYK2cMa1NWi6E3NrCkrEq1WwxM9ih0d+xE0uoN7may3OtIMtaFeGo kvzTENMM21Uv1YnMjhejBw3a7jg9IE9/qdktxI+dntsk+dlYp3nLmfQwvfQyglK6qFYs=; 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=8zYEi4IG7gzAvMHdDHY3fStOc4dh5wVqKWm99G/lD2Q=; b=NDqq4BXaNZ2edLdFHqjTdwRYu8 RSYH6JKkex3t18TEt2FaHgAPyyPv0cPQ2LISrVF0oKYMjeg7R6ntKSK3a2VEFZ5o5K2TPVIgIcZS/ z5lk1xNI1UYbdEjE0qp2wn7Q6u2S7LPKc4VqsrObJLp2WcxkMh0cwAvgpE+212LxArrI=; Received: from bombadil.infradead.org ([198.137.202.133]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1j4WT4-000Gis-UN for linux-f2fs-devel@lists.sourceforge.net; Wed, 19 Feb 2020 21:01:17 +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=8zYEi4IG7gzAvMHdDHY3fStOc4dh5wVqKWm99G/lD2Q=; b=Rr0Isn6KV0yiQsuTepKXa8KVhx +JyO+IlvzFzA0z8sV2iMvtsm9Pv6cgJBZMIpSg1cP4Tx/ZMk08ueKIw29L1ptgphnFq+2Q+86II+5 PJNKMmaiCDdBTTJcDI/iXmLXg84N2WswF5/urdiVm5BTv6ykoK2n3od2eyCx5s1P6nY1KF4YFoSKI volIkWq8cBw6eiWFrgoZdNhCO9tAL9ZiLKXZMPI9znsj3s/nMwWW9pTQdBxelt0H9avPXVOec5UVz t7L9I6CkSyQomfI4fzLa6hPYbkKOJATGVMcI+Zu0LuHW7aFhXW23e3VE3cpt3VyFwn6ldkAqvOfZV bM3ipe0w==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4WSv-0008VZ-JM; Wed, 19 Feb 2020 21:01:05 +0000 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org Date: Wed, 19 Feb 2020 13:01:02 -0800 Message-Id: <20200219210103.32400-24-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200219210103.32400-1-willy@infradead.org> References: <20200219210103.32400-1-willy@infradead.org> MIME-Version: 1.0 X-Headers-End: 1j4WT4-000Gis-UN Subject: [f2fs-dev] [PATCH v7 23/24] mm: Document why we don't set PageReadahead 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)" If the page is already in cache, we don't set PageReadahead on it. Signed-off-by: Matthew Wilcox (Oracle) --- mm/readahead.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index 453ef146de83..bbe7208fcc2d 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -196,9 +196,12 @@ void page_cache_readahead_unbounded(struct address_space *mapping, 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. */ read_pages(&rac, &page_pool); continue; -- 2.25.0 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel