From patchwork Tue Feb 25 21:48:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11404709 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B8D8E138D for ; Tue, 25 Feb 2020 21:50:00 +0000 (UTC) Received: from userp2120.oracle.com (userp2120.oracle.com [156.151.31.85]) (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 8B1FF21927 for ; Tue, 25 Feb 2020 21:50:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8B1FF21927 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=ocfs2-devel-bounces@oss.oracle.com Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01PLWXZE055809; Tue, 25 Feb 2020 21:49:28 GMT Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 2yd0m1vabf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 25 Feb 2020 21:49:28 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01PLi809079393; Tue, 25 Feb 2020 21:49:27 GMT Received: from oss.oracle.com (oss-old-reserved.oracle.com [137.254.22.2]) by userp3020.oracle.com with ESMTP id 2yd17qx5yw-1 (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO); Tue, 25 Feb 2020 21:49:27 +0000 Received: from localhost ([127.0.0.1] helo=lb-oss.oracle.com) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1j6i50-0004ja-Qg; Tue, 25 Feb 2020 13:49:26 -0800 Received: from userp3030.oracle.com ([156.151.31.80]) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1j6i4U-0004dD-FB for ocfs2-devel@oss.oracle.com; Tue, 25 Feb 2020 13:48:54 -0800 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01PLiGkp155063 for ; Tue, 25 Feb 2020 21:48:54 GMT Received: from userp2040.oracle.com (userp2040.oracle.com [156.151.31.90]) by userp3030.oracle.com with ESMTP id 2yd09bk3ey-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 25 Feb 2020 21:48:53 +0000 Received: from pps.filterd (userp2040.oracle.com [127.0.0.1]) by userp2040.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01PLXT3Q011033 for ; Tue, 25 Feb 2020 21:48:53 GMT Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by userp2040.oracle.com with ESMTP id 2yd6df630n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Tue, 25 Feb 2020 21:48:52 +0000 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 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 X-PDR: PASS X-Source-IP: 198.137.202.133 X-ServerName: bombadil.infradead.org X-Proofpoint-SPF-Result: None X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9542 signatures=668685 X-Proofpoint-Spam-Details: rule=tap_spam_policies_notspam policy=tap_spam_policies score=0 lowpriorityscore=0 adultscore=0 bulkscore=0 impostorscore=0 mlxlogscore=819 mlxscore=0 phishscore=0 priorityscore=100 suspectscore=1 spamscore=0 malwarescore=0 clxscore=212 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002250151 X-Spam: Clean X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 phishscore=0 mlxlogscore=999 spamscore=0 adultscore=0 malwarescore=0 bulkscore=0 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002250151 Cc: linux-xfs@vger.kernel.org, John Hubbard , linux-kernel@vger.kernel.org, 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 Subject: [Ocfs2-devel] [PATCH v8 12/25] mm: Move end_index check out of readahead loop X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9542 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 bulkscore=0 mlxlogscore=999 malwarescore=0 adultscore=0 phishscore=0 suspectscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002250151 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9542 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 mlxscore=0 suspectscore=0 bulkscore=0 adultscore=0 impostorscore=0 spamscore=0 phishscore=0 clxscore=1034 priorityscore=1501 malwarescore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002250151 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 = mapping->host; - struct page *page; - unsigned long end_index; /* The last page we want to read */ LIST_HEAD(page_pool); loff_t isize = i_size_read(inode); gfp_t gfp_mask = readahead_gfp_mask(mapping); @@ -178,22 +176,29 @@ void __do_page_cache_readahead(struct address_space *mapping, ._index = index, }; unsigned long i; + pgoff_t end_index; /* The last page we want to read */ if (isize == 0) return; - end_index = ((isize - 1) >> PAGE_SHIFT); + end_index = (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 = ULONG_MAX - index + 1; + /* Don't read past the page containing the last byte of the file */ + if (index + nr_to_read >= end_index) + nr_to_read = end_index - index + 1; /* * Preallocate as many pages as we will need. */ for (i = 0; i < nr_to_read; i++) { - if (index + i > end_index) - break; + struct page *page = xa_load(&mapping->i_pages, index + i); BUG_ON(index + i != rac._index + rac._nr_pages); - page = xa_load(&mapping->i_pages, index + i); if (page && !xa_is_value(page)) { /* * Page already present? Kick off the current batch of