Messages in this thread | | | Date | Sun, 29 Jun 2008 13:34:18 +0200 | From | Martin Sustrik <> | Subject | Re: Higher than expected disk write(2) latency |
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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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