Revision: 54887
http://brlcad.svn.sourceforge.net/brlcad/?rev=54887&view=rev
Author: brlcad
Date: 2013-03-26 20:18:47 +0000 (Tue, 26 Mar 2013)
Log Message:
-----------
apply skriptkid's (akshay kashyap's) gci patch
(http://www.google-melange.com/gci/task/view/google/gci2012/8070202) that
implements cpu thread affinity. initial testing showed a HUGE impact on
massively parallel systems with one 64-core ibm power7 system showing a
benchmark performance improvement around 50% (VGR increase from 120k to 180k).
currently only implemented for pthread systems, but should be easily extended
to other platforms and gives bu_parallel() some initial infrastructure so
bu_parallel threads can know their CPU id. very cool.
Modified Paths:
--------------
brlcad/trunk/include/bu.h
brlcad/trunk/src/libbu/CMakeLists.txt
brlcad/trunk/src/libbu/parallel.c
Added Paths:
-----------
brlcad/trunk/src/libbu/affinity.c
Modified: brlcad/trunk/include/bu.h
===================================================================
--- brlcad/trunk/include/bu.h 2013-03-26 19:25:57 UTC (rev 54886)
+++ brlcad/trunk/include/bu.h 2013-03-26 20:18:47 UTC (rev 54887)
@@ -431,6 +431,18 @@
/*----------------------------------------------------------------------*/
+
+/** @file affinity.c
+ *
+ * Contains utility to set affinity mask of a thread to the CPU set it
+ * is currently running on.
+ *
+ */
+
+BU_EXPORT extern int bu_set_affinity(void);
+
+/*----------------------------------------------------------------------*/
+
/** @addtogroup conv */
/** @ingroup data */
/** @{*/
Modified: brlcad/trunk/src/libbu/CMakeLists.txt
===================================================================
--- brlcad/trunk/src/libbu/CMakeLists.txt 2013-03-26 19:25:57 UTC (rev
54886)
+++ brlcad/trunk/src/libbu/CMakeLists.txt 2013-03-26 20:18:47 UTC (rev
54887)
@@ -11,6 +11,7 @@
BRLCAD_LIB_INCLUDE_DIRS(bu BU_INCLUDE_DIRS BU_LOCAL_INCLUDE_DIRS)
set(LIBBU_SOURCES
+ affinity.c
argv.c
avs.c
backtrace.c
Added: brlcad/trunk/src/libbu/affinity.c
===================================================================
--- brlcad/trunk/src/libbu/affinity.c (rev 0)
+++ brlcad/trunk/src/libbu/affinity.c 2013-03-26 20:18:47 UTC (rev 54887)
@@ -0,0 +1,101 @@
+/* A F F I N I T Y . C
+ * BRL-CAD
+ *
+ * Copyright (c) 2004-2012 United States Government as represented by
+ * the U.S. Army Research Laboratory.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; see the file named COPYING for more
+ * information.
+ */
+
+/** @file affinity.c
+ *
+ * Contains utility to set affinity mask of a thread to the CPU set it
+ * is currently running on.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef HAVE_PTHREAD_H
+# include <pthread.h>
+#endif
+
+/*
+ * bu_set_affinity
+ *
+ * Set affinity mask of current thread to the CPU set it is currently
+ * running on. If it is not running on any CPUs in the set, it is
+ * migrated to CPU 0 by default.
+ *
+ * Return: 0 on Suceess
+ * -1 on Failure
+ *
+ */
+int
+bu_set_affinity(void)
+{
+#if defined(_GNU_SOURCE) && defined(HAVE_PTHREAD_H)
+
+ int cpulim = bu_avail_cpus(); /* Max number of CPUs available for the
process */
+ int status; /* Status of thread setting/getting */
+ int cpu = 0; /* Default CPU number */
+ int j; /* Variable for iteration. */
+
+ cpu_set_t cpuset; /* CPU set structure. Defined
in sched.h */
+ pthread_t curr_thread = pthread_self(); /* Get current thread */
+
+ CPU_ZERO(&cpuset);
+
+ for(j = 0; j < cpulim; j++) { /* Set affinity mask to include CPUs 0 to
max available CPU */
+ CPU_SET(j, &cpuset);
+ }
+
+ status = pthread_getaffinity_np(curr_thread, sizeof(cpu_set_t), &cpuset);
/* Check current affinity mask assigned to thread */
+
+ if(status != 0) { /* Error in getting affinity mask */
+ return -1;
+ }
+
+ for(j = 0; j < CPU_SETSIZE; j++) { /* Check which set has been returned
by pthread_get_affinity */
+ if(CPU_ISSET(j, &cpuset)) {
+ cpu = j;
+ break; /* Break loop since CPU affinity mask has been found */
+ }
+ }
+
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpu, &cpuset); /* Clear CPU set and assign CPUs */
+
+ status = pthread_setaffinity_np(curr_thread, sizeof(cpu_set_t), &cpuset);
/* Set affinity mask of the current */
+
/* thread to CPU set pointed by cpuset */
+
+ if(status != 0) { /* Error in setting affinity mask */
+ return -1;
+ }
+
+#endif
+
+ return 0;
+}
+
+/*
+ * Local Variables:
+ * mode: C
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * c-file-style: "stroustrup"
+ * End:
+ * ex: shiftwidth=4 tabstop=8
+ */
Property changes on: brlcad/trunk/src/libbu/affinity.c
___________________________________________________________________
Added: svn:mime-type
+ text/plain
Added: svn:eol-style
+ native
Modified: brlcad/trunk/src/libbu/parallel.c
===================================================================
--- brlcad/trunk/src/libbu/parallel.c 2013-03-26 19:25:57 UTC (rev 54886)
+++ brlcad/trunk/src/libbu/parallel.c 2013-03-26 20:18:47 UTC (rev 54887)
@@ -165,6 +165,11 @@
} bu_taskcontrol[MAX_PSW];
#endif
+struct thread_data {
+ void (*user_func)(int, genptr_t);
+ genptr_t user_arg;
+ int cpu_id;
+};
void
bu_nice_set(int newnice)
@@ -569,6 +574,12 @@
static genptr_t parallel_arg; /* User's arg to his threads */
static void (*parallel_func)(int, genptr_t); /* user function to run in
parallel */
+HIDDEN void
+parallel_interface_arg(struct thread_data *user_thread_data)
+{
+ bu_set_affinity();
+ (*((*user_thread_data).user_func))((*user_thread_data).cpu_id,
(*user_thread_data).user_arg);
+}
/**
* Interface layer between bu_parallel and the user's function.
@@ -586,13 +597,18 @@
HIDDEN void
parallel_interface(void)
{
- register int cpu; /* our CPU (thread) number */
+ struct thread_data user_thread_data_pi;
+ bu_set_affinity();
+
+ user_thread_data_pi.user_func = parallel_func;
+ user_thread_data_pi.user_arg = parallel_arg;
+
bu_semaphore_acquire(BU_SEM_SYSCALL);
- cpu = parallel_nthreads_started++;
+ user_thread_data_pi.cpu_id = parallel_nthreads_started++;
bu_semaphore_release(BU_SEM_SYSCALL);
- (*parallel_func)(cpu, parallel_arg);
+ parallel_interface_arg(&user_thread_data_pi);
bu_semaphore_acquire(BU_SEM_SYSCALL);
parallel_nthreads_finished++;
@@ -608,6 +624,7 @@
if (cpu) _exit(0);
# endif /* SGI */
}
+
#endif /* PARALLEL */
#ifdef SGI_4D
@@ -639,6 +656,8 @@
(*func)(0, arg);
#else
+
+ struct thread_data *user_thread_data_bu;
int avail_cpus = 1;
# if defined(alliant) && !defined(i860) && !__STDC__
@@ -692,6 +711,15 @@
parallel_func = func;
parallel_arg = arg;
+ user_thread_data_bu = (struct thread_data *)bu_calloc(ncpu,
sizeof(*user_thread_data_bu), "struct thread_data *user_thread_data_bu");
+
+ /* Fill in the data of user_thread_data_bu structures of all threads */
+ for(x = 0; x < ncpu; x++) {
+ (user_thread_data_bu + x)->user_func = func;
+ (user_thread_data_bu + x)->user_arg = arg;
+ (user_thread_data_bu + x)->cpu_id = x;
+ }
+
/* if we're in debug mode, allow additional cpus */
if (!(bu_debug & BU_DEBUG_PARALLEL)) {
avail_cpus = bu_avail_cpus();
@@ -929,11 +957,11 @@
/* Create the threads */
for (x = 0; x < ncpu; x++) {
- if (thr_create(0, 0, (void *(*)(void *))parallel_interface, 0, 0,
&thread)) {
+ if (thr_create(0, 0, (void *(*)(void *))parallel_interface_arg,
(user_thread_data_bu + x), 0, &thread)) {
fprintf(stderr, "ERROR: bu_parallel: thr_create(0x0, 0x0, 0x%x,
0x0, 0, 0x%x) failed on processor %d\n",
- parallel_interface, &thread, x);
+ parallel_interface_arg, &thread, x);
bu_log("ERROR: bu_parallel: thr_create(0x0, 0x0, 0x%x, 0x0, 0,
0x%x) failed on processor %d\n",
- parallel_interface, &thread, x);
+ parallel_interface_arg, &thread, x);
/* Not much to do, lump it */
} else {
if (UNLIKELY(bu_debug & BU_DEBUG_PARALLEL))
@@ -1004,17 +1032,17 @@
pthread_attr_init(&attrs);
pthread_attr_setstacksize(&attrs, 10*1024*1024);
- if (pthread_create(&thread, &attrs, (void *(*)(void
*))parallel_interface, NULL)) {
- fprintf(stderr, "ERROR: bu_parallel: thr_create(0x0, 0x0, 0x%lx,
0x0, 0, 0x%lx) failed on processor %d\n",
- (unsigned long int)parallel_interface, (unsigned long
int)&thread, x);
- bu_log("ERROR: bu_parallel: thr_create(0x0, 0x0, 0x%lx, 0x0, 0, %p)
failed on processor %d\n",
- (unsigned long int)parallel_interface, (void *)&thread, x);
+ if (pthread_create(&thread, &attrs, (void *(*)(void
*))parallel_interface_arg, (user_thread_data_bu + x))) {
+ fprintf(stderr, "ERROR: bu_parallel: pthread_create(0x0, 0x0,
0x%lx, 0x0, 0, 0x%lx) failed on processor %d\n",
+ (unsigned long int)parallel_interface_arg, (unsigned long
int)&thread, x);
+ bu_log("ERROR: bu_parallel: pthread_create(0x0, 0x0, 0x%lx, 0x0, 0,
%p) failed on processor %d\n",
+ (unsigned long int)parallel_interface_arg, (void *)&thread,
x);
/* Not much to do, lump it */
} else {
if (UNLIKELY(bu_debug & BU_DEBUG_PARALLEL)) {
bu_log("bu_parallel(): created thread: (thread: %p) (loop:%d)
(nthreadc:%d)\n",
(void*)thread, x, nthreadc);
- }
+ }
thread_tbl[nthreadc] = thread;
nthreadc++;
@@ -1079,13 +1107,15 @@
/* Create the Win32 threads */
for( int i = 0; i < ncpu; i++){
+
hThreadArray[i] = CreateThread(
NULL,
0,
(LPVOID)parallel_interface,
- NULL,
+ (user_thread_data_bu + x),
0,
&dwThreadIdArray[i]);
+
if (hThreadArray[i] == NULL) {
bu_log("bu_parallel(): Error in CreateThread");
bu_exit();
@@ -1137,6 +1167,8 @@
# endif
bu_pid_of_initiating_thread = 0; /* No threads any more */
+ bu_free(user_thread_data_bu, "struct thread_data *user_thread_data_bu");
+
#endif /* PARALLEL */
return;
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