linux/Documentation/block
Dan Williams 5757a6d76c block: strict rq_affinity
Some systems benefit from completions always being steered to the strict
requester cpu rather than the looser "per-socket" steering that
blk_cpu_to_group() attempts by default. This is because the first
CPU in the group mask ends up being completely overloaded with work,
while the others (including the original submitter) has power left
to spare.

Allow the strict mode to be set by writing '2' to the sysfs control
file. This is identical to the scheme used for the nomerges file,
where '2' is a more aggressive setting than just being turned on.

echo 2 > /sys/block/<bdev>/queue/rq_affinity

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Roland Dreier <roland@purestorage.com>
Tested-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-23 20:44:25 +02:00
..
00-INDEX
biodoc.txt Fix common misspellings 2011-03-31 11:26:23 -03:00
capability.txt
cfq-iosched.txt
data-integrity.txt
deadline-iosched.txt
ioprio.txt
queue-sysfs.txt block: strict rq_affinity 2011-07-23 20:44:25 +02:00
request.txt
stat.txt
switching-sched.txt Documentation: remove anticipatory scheduler info 2010-11-11 12:09:59 +01:00
writeback_cache_control.txt