linux/Documentation/block/queue-sysfs.txt, branch v3.0.62Linux kernel source treehttps://git.amat.us/linux/atom/Documentation/block/queue-sysfs.txt?h=v3.0.622010-01-29T08:04:08Zblock: Added in stricter no merge semantics for block I/O2010-01-29T08:04:08ZAlan D. BrunelleAlan.Brunelle@hp.com2010-01-29T08:04:08Zurn:sha1:488991e28e55b4fbca8067edf0259f69d1a6f92c
Updated 'nomerges' tunable to accept a value of '2' - indicating that _no_
merges at all are to be attempted (not even the simple one-hit cache).
The following table illustrates the additional benefit - 5 minute runs of
a random I/O load were applied to a dozen devices on a 16-way x86_64 system.
nomerges Throughput %System Improvement (tput / %sys)
-------- ------------ ----------- -------------------------
0 12.45 MB/sec 0.669365609
1 12.50 MB/sec 0.641519199 0.40% / 2.71%
2 12.52 MB/sec 0.639849750 0.56% / 2.96%
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
block: add text file detailing queue/ sysfs files2009-02-02T12:02:31ZJens Axboejens.axboe@oracle.com2009-02-02T12:02:31Zurn:sha1:cbb5901b904e122139e97c6f4caed9b1f13c3455
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>