AC_SYS_LARGEFILE
dnl ** check for specific header (.h) files that we are interested in
-AC_CHECK_HEADERS([bfd.h ctype.h dirent.h dlfcn.h errno.h fcntl.h grp.h limits.h locale.h nlist.h pthread.h pwd.h signal.h sys/mman.h sys/resource.h sys/time.h sys/timeb.h sys/timers.h sys/times.h sys/utsname.h sys/wait.h termios.h time.h utime.h windows.h winsock.h])
+AC_CHECK_HEADERS([bfd.h ctype.h dirent.h dlfcn.h errno.h fcntl.h grp.h limits.h locale.h nlist.h pthread.h pwd.h signal.h sys/mman.h sys/resource.h sys/time.h sys/timeb.h sys/timers.h sys/times.h sys/utsname.h sys/wait.h termios.h time.h utime.h windows.h winsock.h sched.h])
dnl ** check if it is safe to include both <time.h> and <sys/time.h>
AC_HEADER_TIME
dnl ** check for more functions
dnl ** The following have been verified to be used in ghc/, but might be used somewhere else, too.
-AC_CHECK_FUNCS([getclock getrusage gettimeofday setitimer siginterrupt sysconf times ctime_r])
+AC_CHECK_FUNCS([getclock getrusage gettimeofday setitimer siginterrupt sysconf times ctime_r, sched_setaffinity])
AC_TRY_RUN([
#include <sys/types.h>
void freeThreadLocalKey (ThreadLocalKey *key);
// Processors and affinity
-nat getNumberOfProcessors (void);
-
+nat getNumberOfProcessors (void);
+void setThreadAffinity (nat n, nat m);
#endif // !CMINUSMINUS
#else
rtsBool parGcGen; /* do parallel GC in this generation
* and higher only */
rtsBool parGcLoadBalancing; /* do load-balancing in parallel GC */
+ rtsBool setAffinity; /* force thread affinity with CPUs */
};
#endif /* THREADED_RTS */
RtsFlags.ParFlags.parGcEnabled = 1;
RtsFlags.ParFlags.parGcGen = 1;
RtsFlags.ParFlags.parGcLoadBalancing = 1;
+ RtsFlags.ParFlags.setAffinity = 0;
#endif
#ifdef PAR
" -N Determine the number of processors to use automatically",
" -q1 Use one OS thread for GC (turns off parallel GC)",
" -qg<n> Use parallel GC only for generations >= <n> (default: 1)",
+" -qb Disable load-balancing in the parallel GC",
+" -qa Use the OS to set thread affinity",
" -qm Don't automatically migrate threads between CPUs",
" -qw Migrate a thread to the current CPU when it is woken up",
#endif
case 'b':
RtsFlags.ParFlags.parGcLoadBalancing = rtsFalse;
break;
+ case 'a':
+ RtsFlags.ParFlags.setAffinity = rtsTrue;
+ break;
case 'm':
RtsFlags.ParFlags.migrate = rtsFalse;
break;
cap = task->cap;
RELEASE_LOCK(&task->lock);
+ if (RtsFlags.ParFlags.setAffinity) {
+ setThreadAffinity(cap->no, n_capabilities);
+ }
+
// set the thread-local pointer to the Task:
taskEnter(task);
*
* --------------------------------------------------------------------------*/
-#if defined(DEBUG) && defined(__linux__)
+#if defined(__linux__)
/* We want GNU extensions in DEBUG mode for mutex error checking */
+/* We also want the affinity API, which requires _GNU_SOURCE */
#define _GNU_SOURCE
#endif
#error pthreads.h is required for the threaded RTS on Posix platforms
#endif
+#if defined(HAVE_SCHED_H)
+#include <sched.h>
+#endif
+
/*
* This (allegedly) OS threads independent layer was initially
* abstracted away from code that used Pthreads, so the functions
return nproc;
}
+// Schedules the thread to run on CPU n of m. m may be less than the
+// number of physical CPUs, in which case, the thread will be allowed
+// to run on CPU n, n+m, n+2m etc.
+void
+setThreadAffinity (nat n, nat m)
+{
+#if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_SETAFFINITY)
+ nat nproc;
+ cpu_set_t cs;
+ nat i;
+
+ nproc = getNumberOfProcessors();
+ CPU_ZERO(&cs);
+ for (i = n; i < nproc; i+=m) {
+ CPU_SET(n, &cs);
+ }
+ sched_setaffinity(0, sizeof(cpu_set_t), &cs);
+#endif
+}
+
#else /* !defined(THREADED_RTS) */
int
return nproc;
}
+void
+setThreadAffinity (nat n STG_UNUSED, nat m STG_UNUSED)
+{
+ /* ToDo */
+}
+
#else /* !defined(THREADED_RTS) */
int