From patchwork Sat Feb 1 15:12:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11361115 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 83D6D139A for ; Sat, 1 Feb 2020 15:13:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 585FE2070C for ; Sat, 1 Feb 2020 15:13:30 +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="sg8vRCPj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726946AbgBAPMn (ORCPT ); Sat, 1 Feb 2020 10:12:43 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:51818 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726677AbgBAPMm (ORCPT ); Sat, 1 Feb 2020 10:12:42 -0500 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: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=6RY0UUjdaQhDdTRUN9wz8mjIn266EGtHTTMcbVMwTms=; b=sg8vRCPjK4w0XFjy7NZSoRgAsd sBqqUd+isaXbSIeuUVYJtJcfV1jXRDPy/1U16VGmZmw7bTQ2rLIGBTuQKAD/evbIN/2CGbqf86yup XZ76ZxqM71IlldJbmwKxuiwssBnvs5ewBtmJYaNdUdUO6dOPG3sciLrooImEXaiNT1xW8H07J2elq MLCqW63FKLppkTHRkeZA8wHWWlexMlCPdis108H2QqcdbP7xU7qfs0u4ZevSD35ABj+qvZpfKPRbf WCKm37R+Iue4NcPjCNjV5Q89mRHaRwM5fowkUIPipwzn+iV7HDCMv8T9DB6eFWwAwMXNJ5OgUQWmH 9h9aE2Jw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ixuRu-0006HP-4H; Sat, 01 Feb 2020 15:12:42 +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, linux-xfs@vger.kernel.org, cluster-devel@redhat.com, ocfs2-devel@oss.oracle.com Subject: [PATCH v4 03/12] readahead: Put pages in cache earlier Date: Sat, 1 Feb 2020 07:12:31 -0800 Message-Id: <20200201151240.24082-4-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200201151240.24082-1-willy@infradead.org> References: <20200201151240.24082-1-willy@infradead.org> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: "Matthew Wilcox (Oracle)" At allocation time, put the pages in the cache unless we're using ->readpages. Signed-off-by: Matthew Wilcox (Oracle) Cc: linux-btrfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Cc: linux-ext4@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: linux-xfs@vger.kernel.org Cc: cluster-devel@redhat.com Cc: ocfs2-devel@oss.oracle.com --- mm/readahead.c | 64 ++++++++++++++++++++++++++++++++++---------------- 1 file changed, 44 insertions(+), 20 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index fc77d13af556..7daef0038b14 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -114,10 +114,10 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages, EXPORT_SYMBOL(read_cache_pages); static void read_pages(struct address_space *mapping, struct file *filp, - struct list_head *pages, unsigned int nr_pages, gfp_t gfp) + struct list_head *pages, pgoff_t start, + unsigned int nr_pages) { struct blk_plug plug; - unsigned page_idx; blk_start_plug(&plug); @@ -125,18 +125,17 @@ static void read_pages(struct address_space *mapping, struct file *filp, mapping->a_ops->readpages(filp, mapping, pages, nr_pages); /* Clean up the remaining pages */ put_pages_list(pages); - goto out; - } + } else { + struct page *page; + unsigned long index; - for (page_idx = 0; page_idx < nr_pages; page_idx++) { - struct page *page = lru_to_page(pages); - list_del(&page->lru); - if (!add_to_page_cache_lru(page, mapping, page->index, gfp)) + xa_for_each_range(&mapping->i_pages, index, page, start, + start + nr_pages - 1) { mapping->a_ops->readpage(filp, page); - put_page(page); + put_page(page); + } } -out: blk_finish_plug(&plug); } @@ -153,13 +152,14 @@ unsigned long __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; + pgoff_t page_offset; unsigned long nr_pages = 0; loff_t isize = i_size_read(inode); gfp_t gfp_mask = readahead_gfp_mask(mapping); + bool use_list = mapping->a_ops->readpages; if (isize == 0) goto out; @@ -170,21 +170,32 @@ unsigned long __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++) { - pgoff_t page_offset = offset + page_idx; + struct page *page; + page_offset = offset + page_idx; if (page_offset > end_index) break; 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. */ if (nr_pages) - read_pages(mapping, filp, &page_pool, nr_pages, - gfp_mask); + read_pages(mapping, filp, &page_pool, + page_offset - nr_pages, + nr_pages); + /* + * It's possible this page is the page we should + * be marking with PageReadahead. However, we + * don't have a stable ref to this page so it might + * be reallocated to another user before we can set + * the bit. There's probably another page in the + * cache marked with PageReadahead from the other + * process which accessed this file. + */ nr_pages = 0; continue; } @@ -192,8 +203,20 @@ unsigned long __do_page_cache_readahead(struct address_space *mapping, page = __page_cache_alloc(gfp_mask); if (!page) break; - page->index = page_offset; - list_add(&page->lru, &page_pool); + if (use_list) { + page->index = page_offset; + list_add(&page->lru, &page_pool); + } else if (add_to_page_cache_lru(page, mapping, page_offset, + gfp_mask) < 0) { + if (nr_pages) + read_pages(mapping, filp, &page_pool, + page_offset - nr_pages, + nr_pages); + put_page(page); + nr_pages = 0; + continue; + } + if (page_idx == nr_to_read - lookahead_size) SetPageReadahead(page); nr_pages++; @@ -205,7 +228,8 @@ unsigned long __do_page_cache_readahead(struct address_space *mapping, * will then handle the error. */ if (nr_pages) - read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask); + read_pages(mapping, filp, &page_pool, page_offset - nr_pages, + nr_pages); BUG_ON(!list_empty(&page_pool)); out: return nr_pages;