+ mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty.patch added to -mm tree

+ mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/truncate: bail out early from invalidate_inode_pages2_range() if mapping is empty
has been added to the -mm tree.  Its filename is
     mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty.patch

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------------------------------------------------------
From: Andrey Ryabinin <aryabinin@virtuozzo.com>
Subject: mm/truncate: bail out early from invalidate_inode_pages2_range() if mapping is empty

If mapping is empty (both ->nrpages and ->nrexceptional is zero) we can
avoid pointless lookups in empty radix tree and bail out immediately after
cleancache invalidation.

Link: http://lkml.kernel.org/r/20170424164135.22350-4-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexey Kuznetsov <kuznet@virtuozzo.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/truncate.c |    3 +++
 1 file changed, 3 insertions(+)

diff -puN mm/truncate.c~mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty mm/truncate.c
--- a/mm/truncate.c~mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty
+++ a/mm/truncate.c
@@ -624,6 +624,9 @@ int invalidate_inode_pages2_range(struct
 	int did_range_unmap = 0;
 
 	cleancache_invalidate_inode(mapping);
+	if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
+		return 0;
+
 	pagevec_init(&pvec, 0);
 	index = start;
 	while (index <= end && pagevec_lookup_entries(&pvec, mapping, index,
_

Patches currently in -mm which might be from aryabinin@virtuozzo.com are

fs-fix-data-invalidation-in-the-cleancache-during-direct-io.patch
fs-block_dev-always-invalidate-cleancache-in-invalidate_bdev.patch
mm-truncate-bail-out-early-from-invalidate_inode_pages2_range-if-mapping-is-empty.patch
mm-truncate-avoid-pointless-cleancache_invalidate_inode-calls.patch