From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1851) id 6BAAB383800F; Wed, 21 Apr 2021 14:19:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6BAAB383800F MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Martin Liska To: gcc-cvs@gcc.gnu.org Subject: [gcc r12-39] Use std::thread::hardware_concurrency in lto-wrapper.c. X-Act-Checkin: gcc X-Git-Author: Martin Liska X-Git-Refname: refs/heads/master X-Git-Oldrev: 8f48ec0946abdc036d74a157623b45fddd864a72 X-Git-Newrev: 0a18305ee11e139838771f96c5a037a29606236e Message-Id: <20210421141912.6BAAB383800F@sourceware.org> Date: Wed, 21 Apr 2021 14:19:12 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Apr 2021 14:19:12 -0000 https://gcc.gnu.org/g:0a18305ee11e139838771f96c5a037a29606236e commit r12-39-g0a18305ee11e139838771f96c5a037a29606236e Author: Martin Liska Date: Thu Mar 11 11:37:50 2021 +0100 Use std::thread::hardware_concurrency in lto-wrapper.c. gcc/ChangeLog: * lto-wrapper.c (cpuset_popcount): Remove. (init_num_threads): Remove and use hardware_concurrency. Diff: --- gcc/lto-wrapper.c | 113 +++--------------------------------------------------- 1 file changed, 5 insertions(+), 108 deletions(-) diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c index 03a5922f8ea..ea68490163d 100644 --- a/gcc/lto-wrapper.c +++ b/gcc/lto-wrapper.c @@ -49,6 +49,8 @@ along with GCC; see the file COPYING3. If not see #include "lto-section-names.h" #include "collect-utils.h" +#include + /* Environment variable, used for passing the names of offload targets from GCC driver to lto-wrapper. */ #define OFFLOAD_TARGET_NAMES_ENV "OFFLOAD_TARGET_NAMES" @@ -1199,113 +1201,6 @@ cmp_priority (const void *a, const void *b) return *((const int *)b)-*((const int *)a); } -/* Number of CPUs that can be used for parallel LTRANS phase. */ - -static unsigned long nthreads_var = 0; - -#ifdef HAVE_PTHREAD_AFFINITY_NP -unsigned long cpuset_size; -static unsigned long get_cpuset_size; -cpu_set_t *cpusetp; - -unsigned long -static cpuset_popcount (unsigned long cpusetsize, cpu_set_t *cpusetp) -{ -#ifdef CPU_COUNT_S - /* glibc 2.7 and above provide a macro for this. */ - return CPU_COUNT_S (cpusetsize, cpusetp); -#else -#ifdef CPU_COUNT - if (cpusetsize == sizeof (cpu_set_t)) - /* glibc 2.6 and above provide a macro for this. */ - return CPU_COUNT (cpusetp); -#endif - size_t i; - unsigned long ret = 0; - STATIC_ASSERT (sizeof (cpusetp->__bits[0]) == sizeof (unsigned long int)); - for (i = 0; i < cpusetsize / sizeof (cpusetp->__bits[0]); i++) - { - unsigned long int mask = cpusetp->__bits[i]; - if (mask == 0) - continue; - ret += __builtin_popcountl (mask); - } - return ret; -#endif -} -#endif - -/* At startup, determine the default number of threads. It would seem - this should be related to the number of cpus online. */ - -static void -init_num_threads (void) -{ -#ifdef HAVE_PTHREAD_AFFINITY_NP -#if defined (_SC_NPROCESSORS_CONF) && defined (CPU_ALLOC_SIZE) - cpuset_size = sysconf (_SC_NPROCESSORS_CONF); - cpuset_size = CPU_ALLOC_SIZE (cpuset_size); -#else - cpuset_size = sizeof (cpu_set_t); -#endif - - cpusetp = (cpu_set_t *) xmalloc (gomp_cpuset_size); - do - { - int ret = pthread_getaffinity_np (pthread_self (), gomp_cpuset_size, - cpusetp); - if (ret == 0) - { - /* Count only the CPUs this process can use. */ - nthreads_var = cpuset_popcount (cpuset_size, cpusetp); - if (nthreads_var == 0) - break; - get_cpuset_size = cpuset_size; -#ifdef CPU_ALLOC_SIZE - unsigned long i; - for (i = cpuset_size * 8; i; i--) - if (CPU_ISSET_S (i - 1, cpuset_size, cpusetp)) - break; - cpuset_size = CPU_ALLOC_SIZE (i); -#endif - return; - } - if (ret != EINVAL) - break; -#ifdef CPU_ALLOC_SIZE - if (cpuset_size < sizeof (cpu_set_t)) - cpuset_size = sizeof (cpu_set_t); - else - cpuset_size = cpuset_size * 2; - if (cpuset_size < 8 * sizeof (cpu_set_t)) - cpusetp - = (cpu_set_t *) realloc (cpusetp, cpuset_size); - else - { - /* Avoid fatal if too large memory allocation would be - requested, e.g. kernel returning EINVAL all the time. */ - void *p = realloc (cpusetp, cpuset_size); - if (p == NULL) - break; - cpusetp = (cpu_set_t *) p; - } -#else - break; -#endif - } - while (1); - cpuset_size = 0; - nthreads_var = 1; - free (cpusetp); - cpusetp = NULL; -#endif -#ifdef _SC_NPROCESSORS_ONLN - nthreads_var = sysconf (_SC_NPROCESSORS_ONLN); -#endif -} - -/* FIXME: once using -std=c++11, we can use std::thread::hardware_concurrency. */ - /* Test and return reason why a jobserver cannot be detected. */ static const char * @@ -1389,6 +1284,9 @@ run_gcc (unsigned argc, char *argv[]) const char *incoming_dumppfx = dumppfx = NULL; static char current_dir[] = { '.', DIR_SEPARATOR, '\0' }; + /* Number of CPUs that can be used for parallel LTRANS phase. */ + unsigned long nthreads_var = std::thread::hardware_concurrency (); + /* Get the driver and options. */ collect_gcc = getenv ("COLLECT_GCC"); if (!collect_gcc) @@ -1779,7 +1677,6 @@ cont1: else if (auto_parallel) { char buf[256]; - init_num_threads (); if (nthreads_var == 0) nthreads_var = 1; if (verbose)