Re: Context switch times

David S. Miller
2001-10-04T21:52:55Z

From: Richard Gooch <rgooch@ras.ucalgary.ca>
Date: Thu, 4 Oct 2001 15:39:05 -0600

David S. Miller writes:
> lat_ctx doesn't execute any FPU ops. So at worst this happens once
> on GLIBC program startup, but then never again.

Has something changed? Last I looked, the whole lmbench timing harness
was based on using the FPU.

Oops, that's entirely possible...

But things are usually layed out like this:

capture_start_time();
context_switch_N_times();
capture_end_time();

So the FPU hit is only before/after the runs, not during each and
every iteration.

Franks a lot,
David S. Miller
davem@redhat.com