[petsc-users] Pthread support

[Alexander Goncharov]

Jed,

I actually tried taskset utility, and it did not help.

alex.

On Tue, 2012-07-24 at 14:06 -0500, Jed Brown wrote:
> On Tue, Jul 24, 2012 at 1:59 PM, Barry Smith <bsmith at mcs.anl.gov>
> wrote:
>         But how do you know what cores the other processes on the
>         machine are using? Couldn't they be anything?
> 
> Yes, but a person running a single-process multi-thread job should be
> doing something like (suppose a 32-core machine)
> 
> 
> $ taskset 0x000000ff ./job1 -nthreads 8     # use all slots
> $ taskset 0xffffff00 ./job2 -nthreads 12    # use 12 of 24 "slots"
> arbitrarily
> 
> 
> 
> 
> Now the second job might set affinity by splitting the 24 slots
> between the 12 threads, or it might group them into three groups per
> CPU die, setting 0xff00000000, 0x00ff0000, and 0x0000ff00 for all four
> threads in each of the three groups respectively.