Re: [PATCH] improving O(1)-J9 in heavily threaded situations

Jussi Laako
2002-02-04T23:33:16Z

Ingo Molnar wrote:
>
> what does 'loose datablocks' mean? What application loses datablocks?

My app http://hasas.sf.net

It's because either distributor's send thread isn't woken up and at
pthread_cond_broadcast() or it's not at pthread_cond_wait() because
receiving process is not receiving it's data because of CPU time starvation.
Thus receiving "CPU hog" process is losing blocks of data.

Data path basically is:

1) read() data from soundcard
2) pthread_cond_broadcast() it
3) pthread_cond_wait() returns | there are N of these
4) write() data to tcp socket |

5) read() data from tcp socket
6) pthread_cond_broadcast() it
7) pthread_cond_wait() returns | there are N of these
8) write() data to unix socket | (here the loss probably happens)

9) read() data from unix socket | there are N of these
10) do some CPU hog stuff | (this process doesn't get all
11) write() results to tcp socket | of the data)

12) read() results from tcp socket | ...and N of these
13) scale data for drawing to screen |
14) do a bit system-cpu-time hog drawing to screen |

- Jussi Laako

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