Subject: Re: [linux-audio-dev] Re: high level laaga
From: Paul Davis (pbd_AT_Op.Net)
Date: Sat May 12 2001 - 04:57:22 EEST
Steve - i did some more calibration of your code with rdtsc.
the proc() call takes about 3500 instructions to execute. on my
system, thats about 5usec. the time between SIGUSR1 being received by
the main process averages about 80usec. as i understand your code,
this is basically the time it would take a "server" to tell a "client"
that it had work to do, for the client to do 5usec of computation, and
then tell the server it was done and for us to be back in the server
process. this is on an unloaded (zero length run queue, no memory
pressure) dual PII-450.
i still don't know why your code appears to execute faster in the mp
case, but the numbers above indicate to me that there is no way that
IPC can be used in a scalable way for low-latency work.
--p
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