67 my_bool init_thr_timer(uint alloc_timers)

 68 {

 ...

 88   pthread_attr_setstacksize(&thr_attr,8196);

 ...

 90   if (mysql_thread_create(key_thread_timer, &timer_thread, &thr_attr,

 91                           timer_handler, NULL))

diff --git i/mysys/thr_timer.c w/mysys/thr_timer.c

index b8726617f44..551b0a7b381 100644

--- i/mysys/thr_timer.c

+++ w/mysys/thr_timer.c

@@ -20,12 +20,13 @@

 */

 #include "mysys_priv.h"

 #include "thr_timer.h"

 #include <m_string.h>

 #include <queues.h>

+#include <stdint.h>

 #ifdef HAVE_TIMER_CREATE

 #include <sys/syscall.h>

 #endif

 struct timespec next_timer_expire_time;

@@ -61,12 +62,18 @@ static int compare_timespec(void *not_used __attribute__((unused)),

   @return 0 ok

   @return 1 error; Can't create thread

 */

 static thr_timer_t max_timer_data;

+static void* buf;

+const size_t malloc_size = 128*1024;

+const size_t pre_size = 16*1024;

+const size_t stack_size = 8196;

+const int magic_byte = 0xf7;

+

 my_bool init_thr_timer(uint alloc_timers)

 {

   pthread_attr_t thr_attr;

   my_bool res= 0;

   DBUG_ENTER("init_thr_timer");

@@ -82,13 +89,22 @@ my_bool init_thr_timer(uint alloc_timers)

   queue_insert(&timer_queue, (uchar*) &max_timer_data);

   next_timer_expire_time= max_timer_data.expire_time;

   /* Create a thread to handle timers */

   pthread_attr_init(&thr_attr);

   pthread_attr_setscope(&thr_attr,PTHREAD_SCOPE_PROCESS);

-  pthread_attr_setstacksize(&thr_attr,8196);

+

+  buf = malloc(malloc_size);

+  DBUG_ASSERT(buf != NULL);

+  memset(buf, magic_byte, malloc_size);

+  int ret;

+  //ret = mprotect(buf, pre_size, PROT_NONE);

+  //DBUG_ASSERT(ret == 0);

+  ret = pthread_attr_setstack(&thr_attr, (char*)buf + pre_size, stack_size);

+  DBUG_ASSERT(ret == 0);

+

   thr_timer_inited= 1;

   if (mysql_thread_create(key_thread_timer, &timer_thread, &thr_attr,

                           timer_handler, NULL))

   {

     thr_timer_inited= 0;

     res= 1;

@@ -112,12 +128,25 @@ void end_thr_timer(void)

   mysql_mutex_lock(&LOCK_timer);

   thr_timer_inited= 0;                          /* Signal abort */

   mysql_cond_signal(&COND_timer);

   mysql_mutex_unlock(&LOCK_timer);

   pthread_join(timer_thread, NULL);

+  for (size_t i = 0; i < pre_size; i++) {

+    const unsigned char c = *((unsigned char*)buf + i);

+    if (i > 0 && i % 16 == 0) {

+      fprintf(stderr, "\n");

+    }

+    if (c == magic_byte) {

+      fprintf(stderr, "__ ");

+    } else {

+      fprintf(stderr, "%02hhx ", c);

+    }

+  }

+  fprintf(stderr, "\n");

+

   mysql_mutex_destroy(&LOCK_timer);

   mysql_cond_destroy(&COND_timer);

   delete_queue(&timer_queue);

   DBUG_VOID_RETURN;

 }