Re: Higher than expected disk write(2) latency
From: Martin Sustrik
Date: Sun Jun 29 2008 - 08:03:26 EST
David Newall wrote:
Martin Lucina wrote:
Measurement of the write(2) time is performed using the TSC, so any
latency there is negligible.
Measuring each write is lavish and bound to impact the results. To
measure sustained throughput, get the time only at start and end, and
divide the difference by the number of writes.
Hi,
We're using RDTSC to measure time, which takes ~30 nanoseconds to
complete. I would say this is negligible given that latency of a write
is 5 orders of magnitude higher.
Martin
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