using mt=2 with crafty 22.10 and 20.14

[okoli]

On my Dual Core Intel I try to start crafty with

crafty mt=2
Output of 20.14 :

max threads set to 2
hash table memory = 12M bytes.
pawn hash table memory = 2M bytes.
show book statistics
EGTB access enabled
using tbpath=./TB
0 piece tablebase files found
parallel threads disabled.

Crafty v20.14 (1 cpus)

Output of 22.10

max threads set to 2
hash table memory = 12M bytes.
pawn hash table memory = 2M bytes.
show book statistics
EGTB access enabled
using tbpath=/var/lib/crafty/TB
0 piece tablebase files found
parallel threads disabled.

Crafty v22.10 (1 cpus)

This is also known here:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=425251
And maybe related is:
https://bugs.launchpad.net/ubuntu/+sour ... bug/324617

crafty is compiled with:
Makefile:
linux
opt='$(opt) -DFUTILITY -DFAST -DINLINE_ASM \
-DPOSIX -DSMP -DCPUS=4 -DDGT -DTRACE' \ )

Can anybody enlighten me if I do something wrong or is it just not working?

Any hint will help,

Thanks in advance,

Oliver

[bob]

On my Dual Core Intel I try to start crafty with

crafty mt=2
Output of 20.14 :

max threads set to 2
hash table memory = 12M bytes.
pawn hash table memory = 2M bytes.
show book statistics
EGTB access enabled
using tbpath=./TB
0 piece tablebase files found
parallel threads disabled.

Crafty v20.14 (1 cpus)

Output of 22.10

max threads set to 2
hash table memory = 12M bytes.
pawn hash table memory = 2M bytes.
show book statistics
EGTB access enabled
using tbpath=/var/lib/crafty/TB
0 piece tablebase files found
parallel threads disabled.

Crafty v22.10 (1 cpus)

This is also known here:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=425251
And maybe related is:
https://bugs.launchpad.net/ubuntu/+sour ... bug/324617

crafty is compiled with:
Makefile:
linux
opt='$(opt) -DFUTILITY -DFAST -DINLINE_ASM \
-DPOSIX -DSMP -DCPUS=4 -DDGT -DTRACE' \ )

Can anybody enlighten me if I do something wrong or is it just not working?

Any hint will help,

Thanks in advance,

Oliver

What exactly is the problem? The "parallel threads disabled"??? That's normal. If you add "smpnice=0" that will go away. All it means as that when Crafty is not "thinking" (ponder=off for example and it is the opponent's move) the threads are disabled so that they don't burn CPU. They will work just fine when it is actually searching.

[okoli]

OK, thanks thats helping for 22.10 here I can see that 100% CPU Time is used.

crafty 20.14 does not know the smpnice=0 opion, and even with pondering=on I only have 50% CPU Utilisation. Maybe 20.14 does not support "cores" but only real CPUs.

Sorry to bother you with questions for some "old" crafty code, but its because I have to do bugfixing for the debian linux distro.

Thanks for the help,

Oliver

[bob]

OK, thanks thats helping for 22.10 here I can see that 100% CPU Time is used.

crafty 20.14 does not know the smpnice=0 opion, and even with pondering=on I only have 50% CPU Utilisation. Maybe 20.14 does not support "cores" but only real CPUs.

Sorry to bother you with questions for some "old" crafty code, but its because I have to do bugfixing for the debian linux distro.

Thanks for the help,

Oliver

The program itself is not aware of the difference between cores and processors, that's up to the O/S. Crafty will run fine on multi-core boxes however, including 20.14... so long as you use the mt=2 or smpmt=2 (or whatever N is correct for the number of procesors/cores you want to use...

With the 20.14 you should be able to get 100% cpu with no problems, _unless_ the 20.14 version you have was compiled without SMP support. You can open a command prompt window, cd to the crafty directory and start crafty manually. Then type mt=2 and see if it complains. If so, it means the executable you have was not compiled with SMP support enabled...