Author: Alexandre Oliva <aoliva@redhat.com>

    Add malloc probes for sbrk and heap resizing.

    	* malloc/arena.c (new_heap): New memory_heap_new probe.

    	(grow_heap): New memory_heap_more probe.

    	(shrink_heap): New memory_heap_less probe.

    	(heap_trim): New memory_heap_free probe.

    	* malloc/malloc.c (sysmalloc): New memory_sbrk_more probe.

    	(systrim): New memory_sbrk_less probe.

    	* manual/probes.texi: Document them.

    Add catch-all alloc retry probe.

    	* malloc/arena.c (arena_get_retry): Add memory_arena_retry probe.

    	* manual/probes.texi: Document it.

    Add probes for malloc retries.

    	* malloc/malloc.c (__libc_malloc): Add memory_malloc_retry probe.

    	(__libc_realloc): Add memory_realloc_retry probe.

    	(__libc_memalign): Add memory_memalign_retry probe.

    	(__libc_valloc): Add memory_valloc_retry probe.

    	(__libc_pvalloc): Add memory_pvalloc_retry probe.

    	(__libc_calloc): Add memory_calloc_retry probe.

    	* manual/probes.texi: Document them.

    Add probes for malloc arena changes.

    	* malloc/arena.c (get_free_list): Add probe

    	memory_arena_reuse_free_list.

    	(reused_arena) [PER_THREAD]: Add probes memory_arena_reuse_wait

    	and memory_arena_reuse.

    	(arena_get2) [!PER_THREAD]: Likewise.

    	* malloc/malloc.c (__libc_realloc) [!PER_THREAD]: Add probe

    	memory_arena_reuse_realloc.

    	* manual/probes.texi: Document them.

    Add probes for all changes to malloc options.

    	* malloc/malloc.c (__libc_free): Add

    	memory_mallopt_free_dyn_thresholds probe.

    	(__libc_mallopt): Add multiple memory_mallopt probes.

    	* manual/probes.texi: Document them.

    Add first set of memory probes.

    	* malloc/malloc.c: Include stap-probe.h.

    	(__libc_mallopt): Add memory_mallopt probe.

    	* malloc/arena.c (_int_new_arena): Add memory_arena_new probe.

    	* manual/probes.texi: New.

    	* manual/Makefile (chapters): Add probes.

    	* manual/debug.texi: Set next node.

Index: glibc-2.17-c758a686/malloc/arena.c

===================================================================

--- glibc-2.17-c758a686/malloc/arena.c.orig

+++ glibc-2.17-c758a686/malloc/arena.c

@@ -586,6 +586,7 @@ new_heap(size_t size, size_t top_pad)

   h->size = size;

   h->mprotect_size = size;

   THREAD_STAT(stat_n_heaps++);

+  LIBC_PROBE (memory_heap_new, 2, h, h->size);

   return h;

 }

@@ -611,6 +612,7 @@ grow_heap(heap_info *h, long diff)

   }

   h->size = new_size;

+  LIBC_PROBE (memory_heap_more, 2, h, h->size);

   return 0;

 }

@@ -638,6 +640,7 @@ shrink_heap(heap_info *h, long diff)

   /*fprintf(stderr, "shrink %p %08lx\n", h, new_size);*/

   h->size = new_size;

+  LIBC_PROBE (memory_heap_less, 2, h, h->size);

   return 0;

 }

@@ -679,6 +682,7 @@ heap_trim(heap_info *heap, size_t pad)

       break;

     ar_ptr->system_mem -= heap->size;

     arena_mem -= heap->size;

+    LIBC_PROBE (memory_heap_free, 2, heap, heap->size);

     delete_heap(heap);

     heap = prev_heap;

     if(!prev_inuse(p)) { /* consolidate backward */

@@ -741,6 +745,7 @@ _int_new_arena(size_t size)

   top(a) = (mchunkptr)ptr;

   set_head(top(a), (((char*)h + h->size) - ptr) | PREV_INUSE);

+  LIBC_PROBE (memory_arena_new, 2, a, size);

   tsd_setspecific(arena_key, (void *)a);

   mutex_init(&a->mutex);

   (void)mutex_lock(&a->mutex);

@@ -779,6 +784,7 @@ get_free_list (void)

       if (result != NULL)

 	{

+	  LIBC_PROBE (memory_arena_reuse_free_list, 1, result);

 	  (void)mutex_lock(&result->mutex);

 	  tsd_setspecific(arena_key, (void *)result);

 	  THREAD_STAT(++(result->stat_lock_loop));

@@ -815,9 +821,11 @@ reused_arena (mstate avoid_arena)

     result = result->next;

   /* No arena available.  Wait for the next in line.  */

+  LIBC_PROBE (memory_arena_reuse_wait, 3, &result->mutex, result, avoid_arena);

   (void)mutex_lock(&result->mutex);

  out:

+  LIBC_PROBE (memory_arena_reuse, 2, result, avoid_arena);

   tsd_setspecific(arena_key, (void *)result);

   THREAD_STAT(++(result->stat_lock_loop));

   next_to_use = result->next;

@@ -896,6 +904,7 @@ arena_get2(mstate a_tsd, size_t size, ms

       if (retried)

 	(void)mutex_unlock(&list_lock);

       THREAD_STAT(++(a->stat_lock_loop));

+      LIBC_PROBE (memory_arena_reuse, 2, a, a_tsd);

       tsd_setspecific(arena_key, (void *)a);

       return a;

     }

@@ -908,6 +917,7 @@ arena_get2(mstate a_tsd, size_t size, ms

      locks. */

   if(!retried && mutex_trylock(&list_lock)) {

     /* We will block to not run in a busy loop.  */

+    LIBC_PROBE (memory_arena_reuse_wait, 3, &list_lock, NULL, a_tsd);

     (void)mutex_lock(&list_lock);

     /* Since we blocked there might be an arena available now.  */

@@ -931,6 +941,7 @@ arena_get2(mstate a_tsd, size_t size, ms

 static mstate

 arena_get_retry (mstate ar_ptr, size_t bytes)

 {

+  LIBC_PROBE (memory_arena_retry, 2, bytes, ar_ptr);

   if(ar_ptr != &main_arena) {

     (void)mutex_unlock(&ar_ptr->mutex);

     ar_ptr = &main_arena;

Index: glibc-2.17-c758a686/malloc/malloc.c

===================================================================

--- glibc-2.17-c758a686/malloc/malloc.c.orig

+++ glibc-2.17-c758a686/malloc/malloc.c

@@ -1884,6 +1884,8 @@ static int perturb_byte;

 #define free_perturb(p, n) memset (p, perturb_byte & 0xff, n)

+#include <stap-probe.h>

+

 /* ------------------- Support for multiple arenas -------------------- */

 #include "arena.c"

@@ -2452,8 +2454,10 @@ static void* sysmalloc(INTERNAL_SIZE_T n

     below even if we cannot call MORECORE.

   */

-  if (size > 0)

+  if (size > 0) {

     brk = (char*)(MORECORE(size));

+    LIBC_PROBE (memory_sbrk_more, 2, brk, size);

+  }

   if (brk != (char*)(MORECORE_FAILURE)) {

     /* Call the `morecore' hook if necessary.  */

@@ -2753,6 +2757,8 @@ static int systrim(size_t pad, mstate av

 	(*hook) ();

       new_brk = (char*)(MORECORE(0));

+      LIBC_PROBE (memory_sbrk_less, 2, new_brk, extra);

+

       if (new_brk != (char*)MORECORE_FAILURE) {

 	released = (long)(current_brk - new_brk);

@@ -2862,6 +2868,7 @@ __libc_malloc(size_t bytes)

     return 0;

   victim = _int_malloc(ar_ptr, bytes);

   if(!victim) {

+    LIBC_PROBE (memory_malloc_retry, 1, bytes);

     ar_ptr = arena_get_retry(ar_ptr, bytes);

     if (__builtin_expect(ar_ptr != NULL, 1)) {

       victim = _int_malloc(ar_ptr, bytes);

@@ -2902,6 +2909,8 @@ __libc_free(void* mem)

       {

 	mp_.mmap_threshold = chunksize (p);

 	mp_.trim_threshold = 2 * mp_.mmap_threshold;

+	LIBC_PROBE (memory_mallopt_free_dyn_thresholds, 2,

+		    mp_.mmap_threshold, mp_.trim_threshold);

       }

     munmap_chunk(p);

     return;

@@ -2981,6 +2990,7 @@ __libc_realloc(void* oldmem, size_t byte

 #endif

 #if !defined PER_THREAD

+  LIBC_PROBE (memory_arena_reuse_realloc, 1, ar_ptr);

   /* As in malloc(), remember this arena for the next allocation. */

   tsd_setspecific(arena_key, (void *)ar_ptr);

 #endif

@@ -2994,6 +3004,7 @@ __libc_realloc(void* oldmem, size_t byte

   if (newp == NULL)

     {

       /* Try harder to allocate memory in other arenas.  */

+      LIBC_PROBE (memory_realloc_retry, 2, bytes, oldmem);

       newp = __libc_malloc(bytes);

       if (newp != NULL)

 	{

@@ -3029,6 +3040,7 @@ __libc_memalign(size_t alignment, size_t

     return 0;

   p = _int_memalign(ar_ptr, alignment, bytes);

   if(!p) {

+    LIBC_PROBE (memory_memalign_retry, 2, bytes, alignment);

     ar_ptr = arena_get_retry (ar_ptr, bytes);

     if (__builtin_expect(ar_ptr != NULL, 1)) {

       p = _int_memalign(ar_ptr, alignment, bytes);

@@ -3066,6 +3078,7 @@ __libc_valloc(size_t bytes)

     return 0;

   p = _int_valloc(ar_ptr, bytes);

   if(!p) {

+    LIBC_PROBE (memory_valloc_retry, 1, bytes);

     ar_ptr = arena_get_retry (ar_ptr, bytes);

     if (__builtin_expect(ar_ptr != NULL, 1)) {

       p = _int_memalign(ar_ptr, pagesz, bytes);

@@ -3101,6 +3114,7 @@ __libc_pvalloc(size_t bytes)

   arena_get(ar_ptr, bytes + 2*pagesz + MINSIZE);

   p = _int_pvalloc(ar_ptr, bytes);

   if(!p) {

+    LIBC_PROBE (memory_pvalloc_retry, 1, bytes);

     ar_ptr = arena_get_retry (ar_ptr, bytes + 2*pagesz + MINSIZE);

     if (__builtin_expect(ar_ptr != NULL, 1)) {

       p = _int_memalign(ar_ptr, pagesz, rounded_bytes);

@@ -3177,6 +3191,7 @@ __libc_calloc(size_t n, size_t elem_size

 	 av == arena_for_chunk(mem2chunk(mem)));

   if (mem == 0) {

+    LIBC_PROBE (memory_calloc_retry, 1, sz);

     av = arena_get_retry (av, sz);

     if (__builtin_expect(av != NULL, 1)) {

       mem = _int_malloc(av, sz);

@@ -4695,21 +4710,29 @@ int __libc_mallopt(int param_number, int

   /* Ensure initialization/consolidation */

   malloc_consolidate(av);

+  LIBC_PROBE (memory_mallopt, 2, param_number, value);

+

   switch(param_number) {

   case M_MXFAST:

-    if (value >= 0 && value <= MAX_FAST_SIZE) {

-      set_max_fast(value);

-    }

+    if (value >= 0 && value <= MAX_FAST_SIZE)

+      {

+	LIBC_PROBE (memory_mallopt_mxfast, 2, value, get_max_fast ());

+	set_max_fast(value);

+      }

     else

       res = 0;

     break;

   case M_TRIM_THRESHOLD:

+    LIBC_PROBE (memory_mallopt_trim_threshold, 3, value,

+		mp_.trim_threshold, mp_.no_dyn_threshold);

     mp_.trim_threshold = value;

     mp_.no_dyn_threshold = 1;

     break;

   case M_TOP_PAD:

+    LIBC_PROBE (memory_mallopt_top_pad, 3, value,

+		mp_.top_pad, mp_.no_dyn_threshold);

     mp_.top_pad = value;

     mp_.no_dyn_threshold = 1;

     break;

@@ -4720,33 +4743,45 @@ int __libc_mallopt(int param_number, int

       res = 0;

     else

       {

+	LIBC_PROBE (memory_mallopt_mmap_threshold, 3, value,

+		    mp_.mmap_threshold, mp_.no_dyn_threshold);

 	mp_.mmap_threshold = value;

 	mp_.no_dyn_threshold = 1;

       }

     break;

   case M_MMAP_MAX:

+    LIBC_PROBE (memory_mallopt_mmap_max, 3, value,

+		mp_.n_mmaps_max, mp_.no_dyn_threshold);

     mp_.n_mmaps_max = value;

     mp_.no_dyn_threshold = 1;

     break;

   case M_CHECK_ACTION:

+    LIBC_PROBE (memory_mallopt_check_action, 2, value, check_action);

     check_action = value;

     break;

   case M_PERTURB:

+    LIBC_PROBE (memory_mallopt_perturb, 2, value, perturb_byte);

     perturb_byte = value;

     break;

 #ifdef PER_THREAD

   case M_ARENA_TEST:

     if (value > 0)

-      mp_.arena_test = value;

+      {

+	LIBC_PROBE (memory_mallopt_arena_test, 2, value, mp_.arena_test);

+	mp_.arena_test = value;

+      }

     break;

   case M_ARENA_MAX:

     if (value > 0)

-      mp_.arena_max = value;

+      {

+	LIBC_PROBE (memory_mallopt_arena_max, 2, value, mp_.arena_max);

+	mp_.arena_max = value;

+      }

     break;

 #endif

   }

Index: glibc-2.17-c758a686/manual/Makefile

===================================================================

--- glibc-2.17-c758a686/manual/Makefile.orig

+++ glibc-2.17-c758a686/manual/Makefile

@@ -43,7 +43,7 @@ chapters = $(addsuffix .texi, \

 		       message search pattern io stdio llio filesys	\

 		       pipe socket terminal syslog math arith time	\

 		       resource setjmp signal startup process job nss	\

-		       users sysinfo conf crypt debug)

+		       users sysinfo conf crypt debug probes)

 add-chapters = $(wildcard $(foreach d, $(add-ons), ../$d/$d.texi))

 appendices = lang.texi header.texi install.texi maint.texi platform.texi \

 	     contrib.texi

Index: glibc-2.17-c758a686/manual/probes.texi

===================================================================

--- /dev/null

+++ glibc-2.17-c758a686/manual/probes.texi

@@ -0,0 +1,257 @@

+@node Internal Probes

+@c @node Internal Probes, , Debugging Support, Top

+@c %MENU% Probes to monitor libc internal behavior

+@chapter Internal probes

+

+In order to aid in debugging and monitoring internal behavior,

+@theglibc{} exposes nearly-zero-overhead SystemTap probes marked with

+the @code{libc} provider.

+

+These probes are not part of the @glibcadj{} stable ABI, and they are

+subject to change or removal across releases.  Our only promise with

+regard to them is that, if we find a need to remove or modify the

+arguments of a probe, the modified probe will have a different name, so

+that program monitors relying on the old probe will not get unexpected

+arguments.

+

+@menu

+* Memory Allocation Probes::  Probes in the memory allocation subsystem

+@end menu

+

+@node Memory Allocation Probes

+@section Memory Allocation Probes

+

+These probes are designed to signal relatively unusual situations within

+the virtual memory subsystem of @theglibc{}.  The location and the

+availability of some probes depend on whether per-thread arenas are

+enabled (the default) or disabled at the time @theglibc{} is compiled.

+

+@deftp Probe memory_sbrk_more (void *@var{$arg1}, size_t @var{$arg2})

+This probe is triggered after the main arena is extended by calling

+@code{sbrk}.  Argument @var{$arg1} is the additional size requested to

+@code{sbrk}, and @var{$arg2} is the pointer that marks the end of the

+@code{sbrk} area, returned in response to the request.

+@end deftp

+

+@deftp Probe memory_sbrk_less (void *@var{$arg1}, size_t @var{$arg2})

+This probe is triggered after the size of the main arena is decreased by

+calling @code{sbrk}.  Argument @var{$arg1} is the size released by

+@code{sbrk} (the positive value, rather than the negative value passed

+to @code{sbrk}), and @var{$arg2} is the pointer that marks the end of

+the @code{sbrk} area, returned in response to the request.

+@end deftp

+

+@deftp Probe memory_heap_new (void *@var{$arg1}, size_t @var{$arg2})

+This probe is triggered after a new heap is @code{mmap}ed.  Argument

+@var{$arg1} is a pointer to the base of the memory area, where the

+@code{heap_info} data structure is held, and @var{$arg2} is the size of

+the heap.

+@end deftp

+

+@deftp Probe memory_heap_free (void *@var{$arg1}, size_t @var{$arg2})

+This probe is triggered @emph{before} (unlike the other sbrk and heap

+probes) a heap is completely removed via @code{munmap}.  Argument

+@var{$arg1} is a pointer to the heap, and @var{$arg2} is the size of the

+heap.

+@end deftp

+

+@deftp Probe memory_heap_more (void *@var{$arg1}, size_t @var{$arg2})

+This probe is triggered after a trailing portion of an @code{mmap}ed

+heap is extended.  Argument @var{$arg1} is a pointer to the heap, and

+@var{$arg2} is the new size of the heap.

+@end deftp

+

+@deftp Probe memory_heap_less (void *@var{$arg1}, size_t @var{$arg2})

+This probe is triggered after a trailing portion of an @code{mmap}ed

+heap is released.  Argument @var{$arg1} is a pointer to the heap, and

+@var{$arg2} is the new size of the heap.

+@end deftp

+

+@deftp Probe memory_malloc_retry (size_t @var{$arg1})

+@deftpx Probe memory_realloc_retry (size_t @var{$arg1}, void *@var{$arg2})

+@deftpx Probe memory_memalign_retry (size_t @var{$arg1}, size_t @var{$arg2})

+@deftpx Probe memory_valloc_retry (size_t @var{$arg1})

+@deftpx Probe memory_pvalloc_retry (size_t @var{$arg1})

+@deftpx Probe memory_calloc_retry (size_t @var{$arg1})

+These probes are triggered when the corresponding functions fail to

+obtain the requested amount of memory from the arena in use, before they

+call @code{arena_get_retry} to select an alternate arena in which to

+retry the allocation.  Argument @var{$arg1} is the amount of memory

+requested by the user; in the @code{calloc} case, that is the total size

+computed from both function arguments.  In the @code{realloc} case,

+@var{$arg2} is the pointer to the memory area being resized.  In the

+@code{memalign} case, @var{$arg2} is the alignment to be used for the

+request, which may be stricter than the value passed to the

+@code{memalign} function.

+

+Note that the argument order does @emph{not} match that of the

+corresponding two-argument functions, so that in all of these probes the

+user-requested allocation size is in @var{$arg1}.

+@end deftp

+

+@deftp Probe memory_arena_retry (size_t @var{$arg1}, void *@var{$arg2})

+This probe is triggered within @code{arena_get_retry} (the function

+called to select the alternate arena in which to retry an allocation

+that failed on the first attempt), before the selection of an alternate

+arena.  This probe is redundant, but much easier to use when it's not

+important to determine which of the various memory allocation functions

+is failing to allocate on the first try.  Argument @var{$arg1} is the

+same as in the function-specific probes, except for extra room for

+padding introduced by functions that have to ensure stricter alignment.

+Argument @var{$arg2} is the arena in which allocation failed.

+@end deftp

+

+@deftp Probe memory_arena_new (void *@var{$arg1}, size_t @var{$arg2})

+This probe is triggered when @code{malloc} allocates and initializes an

+additional arena (not the main arena), but before the arena is assigned

+to the running thread or inserted into the internal linked list of

+arenas.  The arena's @code{malloc_state} internal data structure is

+located at @var{$arg1}, within a newly-allocated heap big enough to hold

+at least @var{$arg2} bytes.

+@end deftp

+

+@deftp Probe memory_arena_reuse (void *@var{$arg1}, void *@var{$arg2})

+This probe is triggered when @code{malloc} has just selected an existing

+arena to reuse, and (temporarily) reserved it for exclusive use.

+Argument @var{$arg1} is a pointer to the newly-selected arena, and

+@var{$arg2} is a pointer to the arena previously used by that thread.

+

+When per-thread arenas are enabled, this occurs within

+@code{reused_arena}, right after the mutex mentioned in probe

+@code{memory_arena_reuse_wait} is acquired; argument @var{$arg1} will

+point to the same arena.  In this configuration, this will usually only

+occur once per thread.  The exception is when a thread first selected

+the main arena, but a subsequent allocation from it fails: then, and

+only then, may we switch to another arena to retry that allocations, and

+for further allocations within that thread.

+

+When per-thread arenas are disabled, this occurs within

+@code{arena_get2}, whenever the mutex for the previously-selected arena

+cannot be immediately acquired.

+@end deftp

+

+@deftp Probe memory_arena_reuse_wait (void *@var{$arg1}, void *@var{$arg2}, void *@var{$arg3})

+This probe is triggered when @code{malloc} is about to wait for an arena

+to become available for reuse.  Argument @var{$arg1} holds a pointer to

+the mutex the thread is going to wait on, @var{$arg2} is a pointer to a

+newly-chosen arena to be reused, and @var{$arg3} is a pointer to the

+arena previously used by that thread.

+

+When per-thread arenas are enabled, this occurs within

+@code{reused_arena}, when a thread first tries to allocate memory or

+needs a retry after a failure to allocate from the main arena, there

+isn't any free arena, the maximum number of arenas has been reached, and

+an existing arena was chosen for reuse, but its mutex could not be

+immediately acquired.  The mutex in @var{$arg1} is the mutex of the

+selected arena.

+

+When per-thread arenas are disabled, this occurs within

+@code{arena_get2}, when a thread first tries to allocate memory or the

+mutex of the arena it previously used could not be immediately acquired,

+and none of the existing arenas could be immediately reserved for

+exclusive use.  The mutex in @var{$arg1} is that of the list of arenas,

+and since the arena won't have been selected yet, @var{$arg2} will be

+@code{NULL}.

+@end deftp

+

+@deftp Probe memory_arena_reuse_free_list (void *@var{$arg1})

+This probe is triggered when @code{malloc} has chosen an arena that is

+in the free list for use by a thread, within the @code{get_free_list}

+function.  This probe is only available when @code{malloc} is configured

+to use per-thread arenas.  The argument @var{$arg1} holds a pointer to

+the selected arena.

+@end deftp

+

+@deftp Probe memory_arena_reuse_realloc (void *@var{$arg1})

+This probe is triggered within @code{realloc}, as the arena of the

+current thread is changed to match that in which the given address was

+allocated.  This probe is @emph{not} available when @code{malloc} is

+configured to use per-thread arenas.  The argument @var{$arg1} holds a

+pointer to the newly-selected arena.

+@end deftp

+

+@deftp Probe memory_mallopt (int @var{$arg1}, int @var{$arg2})

+This probe is triggered when function @code{mallopt} is called to change

+@code{malloc} internal configuration parameters, before any change to

+the parameters is made.  The arguments @var{$arg1} and @var{$arg2} are

+the ones passed to the @code{mallopt} function.

+@end deftp

+

+@deftp Probe memory_mallopt_mxfast (int @var{$arg1}, int @var{$arg2})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_MXFAST}, and the requested

+value is in an acceptable range.  Argument @var{$arg1} is the requested

+value, and @var{$arg2} is the previous value of this @code{malloc}

+parameter.

+@end deftp

+

+@deftp Probe memory_mallopt_trim_threshold (int @var{$arg1}, int @var{$arg2}, int @var{$arg3})

+This probe is triggere shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_TRIM_THRESHOLD}.  Argument

+@var{$arg1} is the requested value, @var{$arg2} is the previous value of

+this @code{malloc} parameter, and @var{$arg3} is nonzero if dynamic

+threshold adjustment was already disabled.

+@end deftp

+

+@deftp Probe memory_mallopt_top_pad (int @var{$arg1}, int @var{$arg2}, int @var{$arg3})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_TOP_PAD}.  Argument

+@var{$arg1} is the requested value, @var{$arg2} is the previous value of

+this @code{malloc} parameter, and @var{$arg3} is nonzero if dynamic

+threshold adjustment was already disabled.

+@end deftp

+

+@deftp Probe memory_mallopt_mmap_threshold (int @var{$arg1}, int @var{$arg2}, int @var{$arg3})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_MMAP_THRESHOLD}, and the

+requested value is in an acceptable range.  Argument @var{$arg1} is the

+requested value, @var{$arg2} is the previous value of this @code{malloc}

+parameter, and @var{$arg3} is nonzero if dynamic threshold adjustment

+was already disabled.

+@end deftp

+

+@deftp Probe memory_mallopt_mmap_max (int @var{$arg1}, int @var{$arg2}, int @var{$arg3})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_MMAP_MAX}.  Argument

+@var{$arg1} is the requested value, @var{$arg2} is the previous value of

+this @code{malloc} parameter, and @var{$arg3} is nonzero if dynamic

+threshold adjustment was already disabled.

+@end deftp

+

+@deftp Probe memory_mallopt_check_action (int @var{$arg1}, int @var{$arg2})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_CHECK_ACTION}.  Argument

+@var{$arg1} is the requested value, and @var{$arg2} is the previous

+value of this @code{malloc} parameter.

+@end deftp

+

+@deftp Probe memory_mallopt_perturb (int @var{$arg1}, int @var{$arg2})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_PERTURB}.  Argument

+@var{$arg1} is the requested value, and @var{$arg2} is the previous

+value of this @code{malloc} parameter.

+@end deftp

+

+@deftp Probe memory_mallopt_arena_test (int @var{$arg1}, int @var{$arg2})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_ARENA_TEST}, and the

+requested value is in an acceptable range.  Argument @var{$arg1} is the

+requested value, and @var{$arg2} is the previous value of this

+@code{malloc} parameter.  This probe is only available when per-thread

+arenas are enabled.

+@end deftp

+

+@deftp Probe memory_mallopt_arena_max (int @var{$arg1}, int @var{$arg2})

+This probe is triggered shortly after the @code{memory_mallopt} probe,

+when the parameter to be changed is @code{M_ARENA_MAX}, and the

+requested value is in an acceptable range.  Argument @var{$arg1} is the

+requested value, and @var{$arg2} is the previous value of this

+@code{malloc} parameter.  This probe is only available when per-thread

+arenas are enabled.

+@end deftp

+

+@deftp Probe memory_mallopt_free_dyn_thresholds (int @var{$arg1}, int @var{$arg2})

+This probe is triggered when function @code{free} decides to adjust the

+dynamic brk/mmap thresholds.  Argument @var{$arg1} and @var{$arg2} are

+the adjusted mmap and trim thresholds, respectively.

+@end deftp

Index: glibc-2.17-c758a686/manual/debug.texi

===================================================================

--- glibc-2.17-c758a686/manual/debug.texi.orig

+++ glibc-2.17-c758a686/manual/debug.texi

@@ -1,5 +1,5 @@

 @node Debugging Support

-@c @node Debugging Support, , Cryptographic Functions, Top

+@c @node Debugging Support, Internal Probes, Cryptographic Functions, Top

 @c %MENU% Functions to help debugging applications

 @chapter Debugging support