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
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@362618 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/runtime/src/kmp.h b/runtime/src/kmp.h
index 0133108..f1a8f38 100644
--- a/runtime/src/kmp.h
+++ b/runtime/src/kmp.h
@@ -3263,6 +3263,7 @@
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);
diff --git a/runtime/src/kmp_settings.cpp b/runtime/src/kmp_settings.cpp
index 114cd9c..1afba5b 100644
--- a/runtime/src/kmp_settings.cpp
+++ b/runtime/src/kmp_settings.cpp
@@ -289,6 +289,20 @@
}
} // __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,
diff --git a/runtime/src/z_Linux_util.cpp b/runtime/src/z_Linux_util.cpp
index 7eb782a..b1cf829 100644
--- a/runtime/src/z_Linux_util.cpp
+++ b/runtime/src/z_Linux_util.cpp
@@ -1833,6 +1833,17 @@
__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 */
diff --git a/runtime/test/misc_bugs/stack-propagate.c b/runtime/test/misc_bugs/stack-propagate.c
new file mode 100644
index 0000000..ac289b5
--- /dev/null
+++ b/runtime/test/misc_bugs/stack-propagate.c
@@ -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
+}