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author | Divyesh Shah <dpshah@google.com> | 2009-01-30 12:46:41 +0100 |
---|---|---|
committer | Jens Axboe <jens.axboe@oracle.com> | 2009-01-30 12:47:33 +0100 |
commit | 3a9a3f6cc55418dd1525e636dccbbe13c394f652 (patch) | |
tree | b23c46b8ecec0a338e4e81454e482f7dcd3ded0c /Documentation/i2c | |
parent | bc58ba9468d94d62c56ab9b47173583ec140b165 (diff) |
cfq-iosched: Allow RT requests to pre-empt ongoing BE timeslice
This patch adds the ability to pre-empt an ongoing BE timeslice when a RT
request is waiting for the current timeslice to complete. This reduces the
wait time to disk for RT requests from an upper bound of 4 (current value
of cfq_quantum) to 1 disk request.
Applied Jens' suggeested changes to avoid the rb lookup and use !cfq_class_rt()
and retested.
Latency(secs) for the RT task when doing sequential reads from 10G file.
| only RT | RT + BE | RT + BE + this patch
small (512 byte) reads | 143 | 163 | 145
large (1Mb) reads | 142 | 158 | 146
Signed-off-by: Divyesh Shah <dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'Documentation/i2c')
0 files changed, 0 insertions, 0 deletions