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Subject: Re: How to get more VPU time.

Author: José de Jesús García Ruvalcaba

Date: 13:26:55 04/09/99

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On April 09, 1999 at 15:37:11, Manuel J. Petit de Gabriel wrote:

>On April 08, 1999 at 08:12:09, David Blackman wrote:
>
>>On April 07, 1999 at 16:20:29, José de Jesús García Ruvalcaba wrote:
>>
>>>	I have compiled Faile for my Sparc/Solaris machine, with different compilers
>>>and different options. But it uses very little cpu time.
>>>	My other engines usually go to 50% cpu (it is a two-processor machine, so they
>>>are using a full cpu).
>>>	At first Faile used about 22%, compiled with gcc and its standard makefile. The
>>>first version compiled wuth cc used even less processor time. I have compiled it
>>>again a few times with different options. The best one is consistently using
>>>over 30% in the middle-game and has peaked to 40% in the endgame.
>>>	Those figures are better than the first ones, but still far from what I
>>>consider "good" (that would mean 49% at least).
>>>	Any suggestions to increase the cpu usage? BTW, all those figures are without
>>>any other process (but the systems ones and xboard) running.
>>>	Thanks in advance.
>>
>>Does the hard disc work very hard while the program is running? Maybe you need
>>to set it to use smaller transposition tables.
>>
>>Do these cpu figures include both user and system cpu time for the program, or
>>just user time? If the program is burning lots of system time, maybe you have a
>>problem with un-aligned memory accesses being trapped and emulated in the
>>kernel.
>
>No unaligned memory access in a sparc box: unaligned accesses are not trapped
>into kernel but a SIGBUS is delivered to the program (killing it).
>
>I assume that José is getting statistics for the program using the top utility,
>am I right? If so my guess is that Faile is multithreaded: top in solaris
>has an annoying behaviour. It only shows the stats for the first LWP in
>the proccess.
>
>You can check wether the program is multithreaded by looking at the Makefile
>to see if -lthread or -lpthread (or both) are appended to the link command.
>Alternatively try:
>   ldd faile
>
>if it shows either:
>
>   libpthread.so
>   libthread.so
>
>or both, the program is multithreaded.
>
>To check the load share across CPUs you can try vmstat and mpstat.
>Vmstat gives summary info (the system as a single). Mpstat gives detailed
>info for every CPU (page faults, sys time, user time, interrupts handled
>by each CPU and more). Try the command 'mpstat 1' which will put a line
>of info for evey CPU every second. Check with 'vmstat 1' the number of
>running processes (LWPs in fact).
>
>
>
>Hope this helps.
>
>manuel,

Manuel,
	thanks for your help. Faile is not multi-threaded.
José.



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