[Openmp-commits] [openmp] r362618 - Added propagation of not big initial stack size of master thread to workers.
Andrey Churbanov via Openmp-commits
openmp-commits at lists.llvm.org
Wed Jun 5 09:14:48 PDT 2019
Author: achurbanov
Date: Wed Jun 5 09:14:47 2019
New Revision: 362618
URL: http://llvm.org/viewvc/llvm-project?rev=362618&view=rev
Log:
Added propagation of not big initial stack size of master thread to workers.
Currently implemented only for non-Windows 64-bit platforms.
Differential Revision: https://reviews.llvm.org/D62488
Added:
openmp/trunk/runtime/test/misc_bugs/stack-propagate.c (with props)
Modified:
openmp/trunk/runtime/src/kmp.h
openmp/trunk/runtime/src/kmp_settings.cpp
openmp/trunk/runtime/src/z_Linux_util.cpp
Modified: openmp/trunk/runtime/src/kmp.h
URL: http://llvm.org/viewvc/llvm-project/openmp/trunk/runtime/src/kmp.h?rev=362618&r1=362617&r2=362618&view=diff
==============================================================================
--- openmp/trunk/runtime/src/kmp.h (original)
+++ openmp/trunk/runtime/src/kmp.h Wed Jun 5 09:14:47 2019
@@ -3263,6 +3263,7 @@ extern void __kmp_init_random(kmp_info_t
extern kmp_r_sched_t __kmp_get_schedule_global(void);
extern void __kmp_adjust_num_threads(int new_nproc);
+extern void __kmp_check_stksize(size_t *val);
extern void *___kmp_allocate(size_t size KMP_SRC_LOC_DECL);
extern void *___kmp_page_allocate(size_t size KMP_SRC_LOC_DECL);
Modified: openmp/trunk/runtime/src/kmp_settings.cpp
URL: http://llvm.org/viewvc/llvm-project/openmp/trunk/runtime/src/kmp_settings.cpp?rev=362618&r1=362617&r2=362618&view=diff
==============================================================================
--- openmp/trunk/runtime/src/kmp_settings.cpp (original)
+++ openmp/trunk/runtime/src/kmp_settings.cpp Wed Jun 5 09:14:47 2019
@@ -289,6 +289,20 @@ static void __kmp_stg_parse_bool(char co
}
} // __kmp_stg_parse_bool
+// placed here in order to use __kmp_round4k static function
+void __kmp_check_stksize(size_t *val) {
+ // if system stack size is too big then limit the size for worker threads
+ if (*val > KMP_DEFAULT_STKSIZE * 16) // just a heuristics...
+ *val = KMP_DEFAULT_STKSIZE * 16;
+ if (*val < KMP_MIN_STKSIZE)
+ *val = KMP_MIN_STKSIZE;
+ if (*val > KMP_MAX_STKSIZE)
+ *val = KMP_MAX_STKSIZE; // dead code currently, but may work in future
+#if KMP_OS_DARWIN
+ *val = __kmp_round4k(*val);
+#endif // KMP_OS_DARWIN
+}
+
static void __kmp_stg_parse_size(char const *name, char const *value,
size_t size_min, size_t size_max,
int *is_specified, size_t *out,
Modified: openmp/trunk/runtime/src/z_Linux_util.cpp
URL: http://llvm.org/viewvc/llvm-project/openmp/trunk/runtime/src/z_Linux_util.cpp?rev=362618&r1=362617&r2=362618&view=diff
==============================================================================
--- openmp/trunk/runtime/src/z_Linux_util.cpp (original)
+++ openmp/trunk/runtime/src/z_Linux_util.cpp Wed Jun 5 09:14:47 2019
@@ -1833,6 +1833,17 @@ void __kmp_runtime_initialize(void) {
__kmp_xproc = __kmp_get_xproc();
+#if ! KMP_32_BIT_ARCH
+ struct rlimit rlim;
+ // read stack size of calling thread, save it as default for worker threads;
+ // this should be done before reading environment variables
+ status = getrlimit(RLIMIT_STACK, &rlim);
+ if (status == 0) { // success?
+ __kmp_stksize = rlim.rlim_cur;
+ __kmp_check_stksize(&__kmp_stksize); // check value and adjust if needed
+ }
+#endif /* KMP_32_BIT_ARCH */
+
if (sysconf(_SC_THREADS)) {
/* Query the maximum number of threads */
Added: openmp/trunk/runtime/test/misc_bugs/stack-propagate.c
URL: http://llvm.org/viewvc/llvm-project/openmp/trunk/runtime/test/misc_bugs/stack-propagate.c?rev=362618&view=auto
==============================================================================
--- openmp/trunk/runtime/test/misc_bugs/stack-propagate.c (added)
+++ openmp/trunk/runtime/test/misc_bugs/stack-propagate.c Wed Jun 5 09:14:47 2019
@@ -0,0 +1,65 @@
+// RUN: %libomp-compile-and-run
+
+// https://bugs.llvm.org/show_bug.cgi?id=26540 requested
+// stack size to be propagated from master to workers.
+// Library implements propagation of not too big stack
+// for Linux x86_64 platform (skipped Windows for now).
+//
+// The test checks that workers can use more than 4MB
+// of stack (4MB - was historical default for
+// stack size of worker thread in runtime library).
+
+#include <stdio.h>
+#include <omp.h>
+#if !defined(_WIN32)
+#include <sys/resource.h> // getrlimit
+#endif
+
+#define STK 4800000
+
+double foo(int n, int th)
+{
+ double arr[n];
+ int i;
+ double res = 0.0;
+ for (i = 0; i < n; ++i) {
+ arr[i] = (double)i / (n + 2);
+ }
+ for (i = 0; i < n; ++i) {
+ res += arr[i] / n;
+ }
+ return res;
+}
+
+int main(int argc, char *argv[])
+{
+#if defined(_WIN32)
+ // don't test Windows
+ printf("stack propagation not implemented, skipping test...\n");
+ return 0;
+#else
+ int status;
+ double val = 0.0;
+ int m = STK / 8; // > 4800000 bytes per thread
+ // read stack size of calling thread, save it as default
+ struct rlimit rlim;
+ status = getrlimit(RLIMIT_STACK, &rlim);
+ if (sizeof(void *) > 4 && // do not test 32-bit systems,
+ status == 0 && rlim.rlim_cur > STK) { // or small initial stack size
+#pragma omp parallel reduction(+:val)
+ {
+ val += foo(m, omp_get_thread_num());
+ }
+ } else {
+ printf("too small stack size limit (needs about 8MB), skipping test...\n");
+ return 0;
+ }
+ if (val > 0.1) {
+ printf("passed\n");
+ return 0;
+ } else {
+ printf("failed, val = %f\n", val);
+ return 1;
+ }
+#endif // _WIN32
+}
Propchange: openmp/trunk/runtime/test/misc_bugs/stack-propagate.c
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: openmp/trunk/runtime/test/misc_bugs/stack-propagate.c
------------------------------------------------------------------------------
svn:keywords = Author Date Id Rev URL
Propchange: openmp/trunk/runtime/test/misc_bugs/stack-propagate.c
------------------------------------------------------------------------------
svn:mime-type = text/plain
More information about the Openmp-commits
mailing list