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* [merged] mm-move-end_index-check-out-of-readahead-loop.patch removed from -mm tree
@ 2020-06-02 21:38 akpm
  0 siblings, 0 replies; only message in thread
From: akpm @ 2020-06-02 21:38 UTC (permalink / raw)
  To: darrick.wong, dchinner, ebiggers, gaoxiang25, hch, jaegeuk,
	jhubbard, johannes.thumshirn, joseph.qi, junxiao.bi, mhocko,
	mm-commits, mszeredi, william.kucharski, willy, xiyou.wangcong,
	yuchao0, ziy


The patch titled
     Subject: mm: move end_index check out of readahead loop
has been removed from the -mm tree.  Its filename was
     mm-move-end_index-check-out-of-readahead-loop.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm: move end_index check out of readahead loop

By reducing nr_to_read, we can eliminate this check from inside the loop.

Link: http://lkml.kernel.org/r/20200414150233.24495-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/readahead.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

--- a/mm/readahead.c~mm-move-end_index-check-out-of-readahead-loop
+++ a/mm/readahead.c
@@ -167,8 +167,6 @@ void __do_page_cache_readahead(struct ad
 		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 +176,26 @@ void __do_page_cache_readahead(struct ad
 		._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;
+	/* Don't read past the page containing the last byte of the file */
+	if (nr_to_read > end_index - 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
_

Patches currently in -mm which might be from willy@infradead.org are

mm-simplify-calling-a-compound-page-destructor.patch
ipc-convert-ipcs_idr-to-xarray.patch
ipc-convert-ipcs_idr-to-xarray-update.patch

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2020-06-02 21:38 [merged] mm-move-end_index-check-out-of-readahead-loop.patch removed from -mm tree akpm

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