Fix: Set thread stack size to ulimit soft value

[lttng-tools.git] / src / common / defaults.c

diff --git a/src/common/defaults.c b/src/common/defaults.c
index 974f7c6c7e0a064079657e05a46c40065f4c6e91..00a0265414baaf693a0eb687e8ce05b9a8f23907 100644 (file)
--- a/src/common/defaults.c
+++ b/src/common/defaults.c
@@ -15,40 +15,104 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <stddef.h>
 #include <unistd.h>
+#include <stdbool.h>
+#include <sys/resource.h>
+#include <pthread.h>
 
 #include "defaults.h"
 #include "macros.h"
+#include "align.h"
+#include "error.h"
 
-size_t default_channel_subbuf_size;
-size_t default_metadata_subbuf_size;
-size_t default_kernel_channel_subbuf_size;
-size_t default_ust_pid_channel_subbuf_size;
-size_t default_ust_uid_channel_subbuf_size;
+static bool pthread_attr_init_done;
+static pthread_attr_t tattr;
+static pthread_mutex_t tattr_lock = PTHREAD_MUTEX_INITIALIZER;
 
-static void __attribute__((constructor)) init_defaults(void)
+LTTNG_HIDDEN
+size_t default_get_channel_subbuf_size(void)
 {
-       /*
-        * The libringbuffer won't accept subbuf sizes smaller than the page size.
-        * If the default subbuf size is smaller, replace it by the page size.
-        */
-       long page_size = sysconf(_SC_PAGESIZE);
-
-       if (page_size < 0) {
-               page_size = 0;
+       return max(_DEFAULT_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_metadata_subbuf_size(void)
+{
+       return max(DEFAULT_METADATA_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_kernel_channel_subbuf_size(void)
+{
+       return max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_ust_pid_channel_subbuf_size(void)
+{
+       return max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+size_t default_get_ust_uid_channel_subbuf_size(void)
+{
+       return max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+}
+
+LTTNG_HIDDEN
+pthread_attr_t *default_pthread_attr(void)
+{
+       int ret = 0;
+       size_t ptstacksize;
+       struct rlimit rlim;
+
+       pthread_mutex_lock(&tattr_lock);
+
+       /* Return cached value. */
+       if (pthread_attr_init_done) {
+               goto end;
+       }
+
+       /* Get system stack size limits. */
+       ret = getrlimit(RLIMIT_STACK, &rlim);
+       if (ret < 0) {
+               PERROR("getrlimit");
+               goto error;
+       }
+       DBG("Stack size limits: soft %lld, hard %lld bytes",
+                       (long long) rlim.rlim_cur,
+                       (long long) rlim.rlim_max);
+
+       /* Get pthread default thread stack size. */
+       ret = pthread_attr_getstacksize(&tattr, &ptstacksize);
+       if (ret < 0) {
+               PERROR("pthread_attr_getstacksize");
+               goto error;
+       }
+       DBG("Default pthread stack size is %zu bytes", ptstacksize);
+
+       /* Check if the default pthread stack size honors ulimits. */
+       if (ptstacksize < rlim.rlim_cur) {
+               DBG("Your libc doesn't honor stack size limits, setting thread stack size to soft limit (%lld bytes)",
+                               (long long) rlim.rlim_cur);
+
+               /* Create pthread_attr_t struct with ulimit stack size. */
+               ret = pthread_attr_setstacksize(&tattr, rlim.rlim_cur);
+               if (ret < 0) {
+                       PERROR("pthread_attr_setstacksize");
+                       goto error;
+               }
        }
 
-       default_channel_subbuf_size =
-               max(_DEFAULT_CHANNEL_SUBBUF_SIZE, page_size);
-       default_metadata_subbuf_size =
-               max(DEFAULT_METADATA_SUBBUF_SIZE, page_size);
-       default_kernel_channel_subbuf_size =
-               max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, page_size);
-       default_ust_pid_channel_subbuf_size =
-               max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, page_size);
-       default_ust_uid_channel_subbuf_size =
-               max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, page_size);
+       /* Enable cached value. */
+       pthread_attr_init_done = true;
+end:
+       pthread_mutex_unlock(&tattr_lock);
+       return &tattr;
+error:
+       pthread_mutex_unlock(&tattr_lock);
+       WARN("Failed to initialize pthread attributes, using libc defaults.");
+       return NULL;
 }