From: Marc Mendez (mmendez++at++silicon-worlds.fr)
Date: 12/18/2001 08:43:06
Hi Performers,
I ve got one more 2-cents question (if you need more, just ask, I ll
give you some 8)
First, the platform I m using is Linux RH7.2, pf2.5 (demo licenced for
the moment, might change 8))), SGI330 1CPU
I am trying to animate an object using data coming one per second from
the network.
Those datas are UTC-timestamped.
What I ve tried to do is creating a (default paramed) pthread listening
a socket and when data is present, put it in a buffer.
Another (default paramed) thread looks at that buffer, finds the data
for the current UTC and applies them.
But, I ve noticed that visual performances were bad : a lot of lost
frames and the fps is far below 20 (I need a 25 fps at least for video
projection).
One of the experimentations I led is : commenting out everything in my
two threads and just putting sched_yield() ...
The problem is still the same. It looks like this scheduler is taking ms
for context switching.
So I ve got a typical Linux performance pb ...
Has anyone an idea about how to deal with the few free CPU percents left
on my system ?
One solution might be trying some different values for the system time
slice (default = 100ms, reducing to 10ms might be benefiX). But I dont
know the influence of this on pThread that are user-level scheduled in
my case.
I ve been suggested to use the PFCOMPUTE callback. As I ve never used
it, can it suit my needs ? What kind of computation is allowed and which
one is forbidden in this function ?
My socket reading/managing is totally asynchronous and pfCompute seems
devoted to such a task, is the scheduling behaviour different from the
pthread ones ?
pfThanks,
Marc.
This archive was generated by hypermail 2b29 : Tue Dec 18 2001 - 08:44:39 PST