FGFS-4.1/OpenSceneGraph
4
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

From Marcel Pursche, "The problem is that when OpenThreads is build with the Linux pthreads implementation all threads inherit the processor affinity from their parent thread.

Browse Source 
This behavior is also described in the pthreads man page (http://man7.org/linux/man-pages/man3/pthread_create.3.html):

>
> Linux-specific details
> The new thread inherits copies of the calling thread's capability
> sets (see capabilities(7)) and CPU affinity mask (see
> sched_setaffinity(2)).
>

To prevent this behaviour I wrote a patch that explicitly sets the affinity mask to all cores of the system, if no specific affinity was defined with PThread::setProcessorAffinity(unsigned int) .

Thank you!
"
This commit is contained in:
Robert Osfield 2014-04-07 14:11:14 +00:00
parent 20c0292e97
commit 64979a0c1a
1 changed files with 23 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
src/OpenThreads/pthreads/PThread.cpp
View File

@ -149,7 +149,30 @@ private:
#endif
#endif
}
#if defined(HAVE_PTHREAD_SETAFFINITY_NP) || defined(HAVE_THREE_PARAM_SCHED_SETAFFINITY) || defined(HAVE_TWO_PARAM_SCHED_SETAFFINITY)
else
{
// BUG-fix for linux:
// Each thread inherits the processor affinity mask from its parent thread.
// We need to explicitly set it to all CPUs, if no affinity was specified.
cpu_set_t cpumask;
CPU_ZERO( &cpumask );
for (int i = 0; i < OpenThreads::GetNumberOfProcessors(); ++i)
{
CPU_SET( i, &cpumask );
}
#if defined(HAVE_PTHREAD_SETAFFINITY_NP)
pthread_setaffinity_np( pthread_self(), sizeof(cpumask), &cpumask);
#elif defined(HAVE_THREE_PARAM_SCHED_SETAFFINITY)
sched_setaffinity( 0, sizeof(cpumask), &cpumask );
#elif defined(HAVE_TWO_PARAM_SCHED_SETAFFINITY)
sched_setaffinity( 0, &cpumask );
#endif
}
#endif
ThreadCleanupStruct tcs;
tcs.thread = thread;