The patch titled
Subject: fs/dax.c: fix inefficiency in dax_writeback_mapping_range()
has been added to the -mm tree. Its filename is
dax-fix-inefficiency-in-dax_writeback_mapping_range.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/dax-fix-inefficiency-in-dax_writeback_mapping_range.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/dax-fix-inefficiency-in-dax_writeback_mapping_range.patch
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------------------------------------------------------
From: Jan Kara <jack@xxxxxxx>
Subject: fs/dax.c: fix inefficiency in dax_writeback_mapping_range()
dax_writeback_mapping_range() fails to update iteration index when
searching radix tree for entries needing cache flushing. Thus each
pagevec worth of entries is searched starting from the start which is
inefficient and prone to livelocks. Update index properly.
Link: http://lkml.kernel.org/r/20170619124531.21491-1-jack@xxxxxxx
Fixes: 9973c98ecfda3 ("dax: add support for fsync/sync")
Signed-off-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dax.c | 1 +
1 file changed, 1 insertion(+)
diff -puN fs/dax.c~dax-fix-inefficiency-in-dax_writeback_mapping_range fs/dax.c
--- a/fs/dax.c~dax-fix-inefficiency-in-dax_writeback_mapping_range
+++ a/fs/dax.c
@@ -859,6 +859,7 @@ int dax_writeback_mapping_range(struct a
if (ret < 0)
goto out;
}
+ start_index = indices[pvec.nr - 1] + 1;
}
out:
put_dax(dax_dev);
_
Patches currently in -mm which might be from jack@xxxxxxx are
dax-fix-inefficiency-in-dax_writeback_mapping_range.patch
mm-fix-thp-handling-in-invalidate_mapping_pages.patch