Skip to content

Fix race condition in blas_server_omp.c #1536

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
May 11, 2018
Merged

Fix race condition in blas_server_omp.c #1536

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
1b83341
Fix race condition in blas_server_omp.c
Apr 24, 2018
894433a
Update Makefile.rule
martin-frbg Apr 27, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions Makefile.rule
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -60,6 +60,13 @@ VERSION = 0.3.0.dev
# automatically detected by the the script.
# NUM_THREADS = 24

# If you have enabled USE_OPENMP and your application would call
# OpenBLAS's calculation API from multi threads, please comment it in.
# This flag defines how many instances of OpenBLAS's calculation API can
# actually run in parallel. If more threads call OpenBLAS's calculation API,
# they need to wait for the preceding API calls to finish or risk data corruption.
# NUM_PARALLEL = 2

# if you don't need to install the static library, please comment it in.
# NO_STATIC = 1

Expand Down
6 changes: 6 additions & 0 deletions Makefile.system
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -184,6 +184,10 @@ endif

endif

ifndef NUM_PARALLEL
NUM_PARALLEL = 1
endif

ifndef NUM_THREADS
NUM_THREADS = $(NUM_CORES)
endif
Expand Down Expand Up @@ -961,6 +965,8 @@ endif

CCOMMON_OPT += -DMAX_CPU_NUMBER=$(NUM_THREADS)

CCOMMON_OPT += -DMAX_PARALLEL_NUMBER=$(NUM_PARALLEL)

ifdef USE_SIMPLE_THREADED_LEVEL3
CCOMMON_OPT += -DUSE_SIMPLE_THREADED_LEVEL3
endif
Expand Down
6 changes: 6 additions & 0 deletions cmake/system.cmake
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -96,6 +96,10 @@ if (NOT CMAKE_CROSSCOMPILING)

endif()

if (NOT DEFINED NUM_PARALLEL)
set(NUM_PARALLEL 1)
endif()

if (NOT DEFINED NUM_THREADS)
if (DEFINED NUM_CORES AND NOT NUM_CORES EQUAL 0)
# HT?
Expand Down Expand Up @@ -224,6 +228,8 @@ endif ()

set(CCOMMON_OPT "${CCOMMON_OPT} -DMAX_CPU_NUMBER=${NUM_THREADS}")

set(CCOMMON_OPT "${CCOMMON_OPT} -DMAX_PARALLEL_NUMBER=${NUM_PARALLEL}")

if (USE_SIMPLE_THREADED_LEVEL3)
set(CCOMMON_OPT "${CCOMMON_OPT} -DUSE_SIMPLE_THREADED_LEVEL3")
endif ()
Expand Down
2 changes: 1 addition & 1 deletion common.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -179,7 +179,7 @@ extern "C" {

#define ALLOCA_ALIGN 63UL

#define NUM_BUFFERS (MAX_CPU_NUMBER * 2)
#define NUM_BUFFERS (MAX_CPU_NUMBER * 2 * MAX_PARALLEL_NUMBER)

#ifdef NEEDBUNDERSCORE
#define BLASFUNC(FUNC) FUNC##_
Expand Down
91 changes: 66 additions & 25 deletions driver/others/blas_server_omp.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,13 @@
/* or implied, of The University of Texas at Austin. */
/*********************************************************************/

#if _STDC_VERSION__ >= 201112L
#ifndef _Atomic
#define _Atomic volatile
#endif
#include <stdatomic.h>
#endif
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
//#include <sys/mman.h>
Expand All @@ -49,11 +56,16 @@

int blas_server_avail = 0;

static void * blas_thread_buffer[MAX_CPU_NUMBER];
static void * blas_thread_buffer[MAX_PARALLEL_NUMBER][MAX_CPU_NUMBER];
#if _STDC_VERSION__ >= 201112L
static atomic_bool blas_buffer_inuse[MAX_PARALLEL_NUMBER];
#else
static _Bool blas_buffer_inuse[MAX_PARALLEL_NUMBER];
#endif

void goto_set_num_threads(int num_threads) {

int i=0;
int i=0, j=0;

if (num_threads < 1) num_threads = blas_num_threads;

Expand All @@ -68,15 +80,17 @@ void goto_set_num_threads(int num_threads) {
omp_set_num_threads(blas_cpu_number);

//adjust buffer for each thread
for(i=0; i<blas_cpu_number; i++){
if(blas_thread_buffer[i]==NULL){
blas_thread_buffer[i]=blas_memory_alloc(2);
for(i=0; i<MAX_PARALLEL_NUMBER; i++) {
for(j=0; j<blas_cpu_number; j++){
if(blas_thread_buffer[i][j]==NULL){
blas_thread_buffer[i][j]=blas_memory_alloc(2);
}
}
}
for(; i<MAX_CPU_NUMBER; i++){
if(blas_thread_buffer[i]!=NULL){
blas_memory_free(blas_thread_buffer[i]);
blas_thread_buffer[i]=NULL;
for(; j<MAX_CPU_NUMBER; j++){
if(blas_thread_buffer[i][j]!=NULL){
blas_memory_free(blas_thread_buffer[i][j]);
blas_thread_buffer[i][j]=NULL;
}
}
}
#if defined(ARCH_MIPS64)
Expand All @@ -92,30 +106,34 @@ void openblas_set_num_threads(int num_threads) {

int blas_thread_init(void){

int i=0;
int i=0, j=0;

blas_get_cpu_number();

blas_server_avail = 1;

for(i=0; i<blas_num_threads; i++){
blas_thread_buffer[i]=blas_memory_alloc(2);
}
for(; i<MAX_CPU_NUMBER; i++){
blas_thread_buffer[i]=NULL;
for(i=0; i<MAX_PARALLEL_NUMBER; i++) {
for(j=0; j<blas_num_threads; j++){
blas_thread_buffer[i][j]=blas_memory_alloc(2);
}
for(; j<MAX_CPU_NUMBER; j++){
blas_thread_buffer[i][j]=NULL;
}
}

return 0;
}

int BLASFUNC(blas_thread_shutdown)(void){
int i=0;
int i=0, j=0;
blas_server_avail = 0;

for(i=0; i<MAX_CPU_NUMBER; i++){
if(blas_thread_buffer[i]!=NULL){
blas_memory_free(blas_thread_buffer[i]);
blas_thread_buffer[i]=NULL;
for(i=0; i<MAX_PARALLEL_NUMBER; i++) {
for(j=0; j<MAX_CPU_NUMBER; j++){
if(blas_thread_buffer[i][j]!=NULL){
blas_memory_free(blas_thread_buffer[i][j]);
blas_thread_buffer[i][j]=NULL;
}
}
}

Expand Down Expand Up @@ -206,7 +224,7 @@ static void legacy_exec(void *func, int mode, blas_arg_t *args, void *sb){
}
}

static void exec_threads(blas_queue_t *queue){
static void exec_threads(blas_queue_t *queue, int buf_index){

void *buffer, *sa, *sb;
int pos=0, release_flag=0;
Expand All @@ -223,7 +241,7 @@ static void exec_threads(blas_queue_t *queue){
if ((sa == NULL) && (sb == NULL) && ((queue -> mode & BLAS_PTHREAD) == 0)) {

pos = omp_get_thread_num();
buffer = blas_thread_buffer[pos];
buffer = blas_thread_buffer[buf_index][pos];

//fallback
if(buffer==NULL) {
Expand Down Expand Up @@ -291,7 +309,7 @@ static void exec_threads(blas_queue_t *queue){

int exec_blas(BLASLONG num, blas_queue_t *queue){

BLASLONG i;
BLASLONG i, buf_index;

if ((num <= 0) || (queue == NULL)) return 0;

Expand All @@ -302,16 +320,39 @@ int exec_blas(BLASLONG num, blas_queue_t *queue){
}
#endif

while(true) {
for(i=0; i < MAX_PARALLEL_NUMBER; i++) {
#if _STDC_VERSION__ >= 201112L
_Bool inuse = false;
if(atomic_compare_exchange_weak(&blas_buffer_inuse[i], &inuse, true)) {
#else
if(blas_buffer_inuse[i] == false) {
blas_buffer_inuse[i] = true;
#endif
buf_index = i;
break;
}
}
if(i != MAX_PARALLEL_NUMBER)
break;
}

#pragma omp parallel for schedule(static)
for (i = 0; i < num; i ++) {

#ifndef USE_SIMPLE_THREADED_LEVEL3
queue[i].position = i;
#endif

exec_threads(&queue[i]);
exec_threads(&queue[i], buf_index);
}

#if _STDC_VERSION__ >= 201112L
atomic_store(&blas_buffer_inuse[buf_index], false);
#else
blas_buffer_inuse[buf_index] = false;
#endif

return 0;
}

Expand Down