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author | Angelo Ruocco <angeloruocco90@gmail.com> | 2017-12-20 12:38:34 +0100 |
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committer | Jens Axboe <axboe@kernel.dk> | 2018-01-05 09:26:11 -0700 |
commit | 4403e4e467c365b4189e3e3d3ad35cf67b8c36ed (patch) | |
tree | 6bc388cb660f4673aacbbcc705030c589c4748e5 /block/blk-mq-cpumap.c | |
parent | 7b8fa3b900a087bc03b11329a92398fde563ba37 (diff) | |
download | linux-4403e4e467c365b4189e3e3d3ad35cf67b8c36ed.tar.bz2 |
block, bfq: remove superfluous check in queue-merging setup
When two or more processes do I/O in a way that the their requests are
sequential in respect to one another, BFQ merges the bfq_queues associated
with the processes. This way the overall I/O pattern becomes sequential,
and thus there is a boost in througput.
These cooperating processes usually start or restart to do I/O shortly
after each other. So, in order to avoid merging non-cooperating processes,
BFQ ensures that none of these queues has been in weight raising for too
long.
In this respect, from commit "block, bfq-sq, bfq-mq: let a queue be merged
only shortly after being created", BFQ checks whether any queue (and not
only weight-raised ones) is doing I/O continuously from too long to be
merged.
This new additional check makes the first one useless: a queue doing
I/O from long enough, if being weight-raised, is also a queue in
weight raising for too long to be merged. Accordingly, this commit
removes the first check.
Signed-off-by: Angelo Ruocco <angeloruocco90@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq-cpumap.c')
0 files changed, 0 insertions, 0 deletions