From patchwork Mon Feb 17 18:45:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11387299 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 2B44417F0 for ; Mon, 17 Feb 2020 18:47:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BBFE222D9 for ; Mon, 17 Feb 2020 18:47:29 +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="MwopgXm2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729960AbgBQSq0 (ORCPT ); Mon, 17 Feb 2020 13:46:26 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:48258 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729945AbgBQSqZ (ORCPT ); Mon, 17 Feb 2020 13:46:25 -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; bh=JHQZUif7GrXF5c6dt1x94JQ/eERbsKsl9szla620yGg=; b=MwopgXm2jrH3SI/KCNCU9kTcM/ dbE6z4ghybS40X+Y522lD+E/Px6QZSdy/WskVldqgb8kNys8BTLFOs9Ix5lX1cQCMVQqBNY0OrA6M SCv5aSifERzuMP8/yzWjikX6Z3wB4tFF1SHtcHtmSpq9fT6oDSWicm0Vbtr37+iu0KFIc29PidL38 kVlwFzmJW+ra21Pw8v6Lc39a5gLT7BcDAW6QvyFTpsZr4vCDl95IvI+nDZChH0dxeoi3k7rD0QpXl m3s4AqkENlFwUpKkFceab08z7tasn1FQzTNd2VM/s+dD0OfE8rlbWrz9U3nQSTby9xGZSfXDdTYgJ 8qXWRWEg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j3lPL-00059e-Lj; Mon, 17 Feb 2020 18:46:15 +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 Subject: [PATCH v6 07/19] mm: Put readahead pages in cache earlier Date: Mon, 17 Feb 2020 10:45:52 -0800 Message-Id: <20200217184613.19668-12-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 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. Add the readahead_for_each() iterator for the benefit of the ->readpage fallback. This iterator supports huge pages, even though none of the filesystems to be converted do yet. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 24 ++++++++++++++++++++++++ mm/readahead.c | 34 +++++++++++++++++----------------- 2 files changed, 41 insertions(+), 17 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 982ecda2d4a2..3613154e79e4 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -639,8 +639,32 @@ struct readahead_control { /* private: use the readahead_* accessors instead */ pgoff_t _start; unsigned int _nr_pages; + unsigned int _batch_count; }; +static inline struct page *readahead_page(struct readahead_control *rac) +{ + struct page *page; + + if (!rac->_nr_pages) + return NULL; + + page = xa_load(&rac->mapping->i_pages, rac->_start); + VM_BUG_ON_PAGE(!PageLocked(page), page); + rac->_batch_count = hpage_nr_pages(page); + + return page; +} + +static inline void readahead_next(struct readahead_control *rac) +{ + rac->_nr_pages -= rac->_batch_count; + rac->_start += rac->_batch_count; +} + +#define readahead_for_each(rac, page) \ + for (; (page = readahead_page(rac)); readahead_next(rac)) + /* The number of pages in this readahead block */ static inline unsigned int readahead_count(struct readahead_control *rac) { diff --git a/mm/readahead.c b/mm/readahead.c index bdc5759000d3..9e430daae42f 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -113,12 +113,11 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages, EXPORT_SYMBOL(read_cache_pages); -static void read_pages(struct readahead_control *rac, struct list_head *pages, - gfp_t gfp) +static void read_pages(struct readahead_control *rac, struct list_head *pages) { const struct address_space_operations *aops = rac->mapping->a_ops; + struct page *page; struct blk_plug plug; - unsigned page_idx; blk_start_plug(&plug); @@ -127,19 +126,13 @@ static void read_pages(struct readahead_control *rac, struct list_head *pages, readahead_count(rac)); /* Clean up the remaining pages */ put_pages_list(pages); - goto out; - } - - for (page_idx = 0; page_idx < readahead_count(rac); page_idx++) { - struct page *page = lru_to_page(pages); - list_del(&page->lru); - if (!add_to_page_cache_lru(page, rac->mapping, page->index, - gfp)) + } else { + readahead_for_each(rac, page) { aops->readpage(rac->file, page); - put_page(page); + put_page(page); + } } -out: blk_finish_plug(&plug); } @@ -159,6 +152,7 @@ void __do_page_cache_readahead(struct address_space *mapping, unsigned long i; loff_t isize = i_size_read(inode); gfp_t gfp_mask = readahead_gfp_mask(mapping); + bool use_list = mapping->a_ops->readpages; struct readahead_control rac = { .mapping = mapping, .file = filp, @@ -196,8 +190,14 @@ void __do_page_cache_readahead(struct address_space *mapping, page = __page_cache_alloc(gfp_mask); if (!page) break; - page->index = offset; - list_add(&page->lru, &page_pool); + if (use_list) { + page->index = offset; + list_add(&page->lru, &page_pool); + } else if (add_to_page_cache_lru(page, mapping, offset, + gfp_mask) < 0) { + put_page(page); + goto read; + } if (i == nr_to_read - lookahead_size) SetPageReadahead(page); rac._nr_pages++; @@ -205,7 +205,7 @@ void __do_page_cache_readahead(struct address_space *mapping, continue; read: if (readahead_count(&rac)) - read_pages(&rac, &page_pool, gfp_mask); + read_pages(&rac, &page_pool); rac._nr_pages = 0; rac._start = ++offset; } @@ -216,7 +216,7 @@ void __do_page_cache_readahead(struct address_space *mapping, * will then handle the error. */ if (readahead_count(&rac)) - read_pages(&rac, &page_pool, gfp_mask); + read_pages(&rac, &page_pool); BUG_ON(!list_empty(&page_pool)); }