Messages in this thread Patch in this message | | | Date | Mon, 18 May 2009 18:38:39 +0900 | From | Hisashi Hifumi <> | Subject | [PATCH] readahead:add blk_run_backing_dev |
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Hi.
I wrote a patch that adds blk_run_backing_dev on page_cache_async_readahead so readahead I/O is unpluged to improve throughput.
Following is the test result with dd.
#dd if=testdir/testfile of=/dev/null bs=16384
-2.6.30-rc6 1048576+0 records in 1048576+0 records out 17179869184 bytes (17 GB) copied, 224.182 seconds, 76.6 MB/s
-2.6.30-rc6-patched 1048576+0 records in 1048576+0 records out 17179869184 bytes (17 GB) copied, 206.465 seconds, 83.2 MB/s
Sequential read performance on a big file was improved. Please merge my patch.
Thanks.
Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
diff -Nrup linux-2.6.30-rc6.org/mm/readahead.c linux-2.6.30-rc6.unplug/mm/readahead.c --- linux-2.6.30-rc6.org/mm/readahead.c 2009-05-18 10:46:15.000000000 +0900 +++ linux-2.6.30-rc6.unplug/mm/readahead.c 2009-05-18 13:00:42.000000000 +0900 @@ -490,5 +490,7 @@ page_cache_async_readahead(struct addres /* do read-ahead */ ondemand_readahead(mapping, ra, filp, true, offset, req_size); + + blk_run_backing_dev(mapping->backing_dev_info, NULL); } EXPORT_SYMBOL_GPL(page_cache_async_readahead);
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