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author | Aaron Carroll <aaronc@gelato.unsw.edu.au> | 2008-08-26 15:52:36 +0200 |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2008-10-09 08:56:09 +0200 |
commit | 45333d5a31296d0af886d94f1d08f128231cab8e (patch) | |
tree | ea5b1afb70fb17935128bac6df588e6b5ae764b4 /fs/hfs | |
parent | 605401618ce4409045bc4db86e88d4b38f2ad585 (diff) |
cfq-iosched: fix queue depth detection
CFQ's detection of queueing devices assumes a non-queuing device and detects
if the queue depth reaches a certain threshold. Under some workloads (e.g.
synchronous reads), CFQ effectively forces a unit queue depth, thus defeating
the detection logic. This leads to poor performance on queuing hardware,
since the idle window remains enabled.
This patch inverts the sense of the logic: assume a queuing-capable device,
and detect if the depth does not exceed the threshold.
Signed-off-by: Aaron Carroll <aaronc@gelato.unsw.edu.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'fs/hfs')
0 files changed, 0 insertions, 0 deletions