Re: Scalable hash map: The defeat of lock-based synchronization

On Oct 1, 3:35=A0pm, Alexander Chemeris <alexander.cheme...@[EMAIL PROTECTED]
>
wrote:

> > I run simple benchmark for around 10 seconds. Every thread count
> > number of executed operations in thread local counter. After 10
> > seconds I stop all threads, and sum all thread local counters. And
> > then divide execution time measured in cycles by total number of
> > operations. Execution time I measure with rdtsc instruction.
> > Usually results very stable, i.e. deviation is no more than few
> > cycles.
>
> How do you get rid of the task switches and the time, spent in
> other threads? Some people just assume that if task switch
> occurred, then time, spent inside a calculation cycle deviate
> a lot from the mean and just through away this timing.
> Do you use the same technique?

I don't get rid of context switches and exterior load. Since I measure
around 10^9 operations, I don't think that it will have some effect.
Machine is maximally relieved of any exterior load while tests are
conducted. I think that bigger mistake will be introduced by measuring
time of every single operation.

Dmitriy V'jukov