From: Jan Kara <jack@suse.cz> To: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com>, Dan Williams <dan.j.williams@intel.com>, linux-nvdimm@lists.01.org, linux-mm@kvack.org, Jan Kara <jack@suse.cz>, stable@vger.kernel.org Subject: [PATCH] dax: Fix inefficiency in dax_writeback_mapping_range() Date: Mon, 19 Jun 2017 14:45:31 +0200 Message-ID: <20170619124531.21491-1-jack@suse.cz> (raw) 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. CC: stable@vger.kernel.org Fixes: 9973c98ecfda3a1dfcab981665b5f1e39bcde64a Signed-off-by: Jan Kara <jack@suse.cz> --- fs/dax.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/dax.c b/fs/dax.c index 2a6889b3585f..9187f3b07f3e 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -859,6 +859,7 @@ int dax_writeback_mapping_range(struct address_space *mapping, if (ret < 0) goto out; } + start_index = indices[pvec.nr - 1] + 1; } out: put_dax(dax_dev); -- 2.12.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next reply index Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-06-19 12:45 Jan Kara [this message] 2017-06-19 16:34 ` Ross Zwisler
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