Messages in this thread | | | Subject | cfq performance gap | From | Avantika Mathur <> | Date | Thu, 07 Dec 2006 16:03:20 -0800 |
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Hi Jens,
I've noticed a performance gap between the cfq scheduler and other io schedulers when running the rawio benchmark. Results from rawio on 2.6.19, cfq and noop schedulers:
CFQ:
procs device num read KB/sec I/O Ops/sec ----- --------------- ---------- ------- -------------- 16 /dev/sda 16412 8338 2084 ----- --------------- ---------- ------- -------------- 16 16412 8338 2084
Total run time 0.492072 seconds
NOOP:
procs device num read KB/sec I/O Ops/sec ----- --------------- ---------- ------- -------------- 16 /dev/sda 16399 29224 7306 ----- --------------- ---------- ------- -------------- 16 16399 29224 7306
Total run time 0.140284 seconds
The benchmark workload is 16 processes running 4k random reads.
Is this performance gap a known issue? Thanks, Avantika Mathur
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