Subject: Re: [linux-audio-dev] Performance and Elegance? (Was: High Cost of IPC)
From: Peter Hanappe (peter_AT_hanappe.com)
Date: Wed May 16 2001 - 15:23:35 EEST
John Regehr wrote:
> [...] a context switch always involves a few
> microseconds in the kernel, on a 500 MHz PIII it can take an app about
> 4ms to reestablish its working set in the cache after a context switch
> when the cache is cold and the working set is nearly the size of the
> cache. This means that the cache cost is close to three orders of
> magnitude bigger than the nominal context switch cost. Ugly!
>
> Of course, if threads have small working sets or they are thrashing the
> cache anyway then this penalty would be much smaller. Ironically,
> however, the best-tuned applications, the ones whose working sets just
> fit into the cache, are most heavily penalized by context switches.
What's a simple way to measure the working set of a process or thread.
I'd like to check it on my project.
(I'll check out your thesis for the details later ;)
Thanks
-- Peter Hanappe peter_AT_hanappe.com
This archive was generated by hypermail 2b28 : Thu May 24 2001 - 02:07:51 EEST