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[PATCH 6/6] Add malloc probes for sbrk and heap resizing.
- From: Alexandre Oliva <aoliva at redhat dot com>
- To: libc-alpha at sourceware dot org
- Cc: carlos at redhat dot com, aj at suse dot com
- Date: Thu, 19 Sep 2013 12:10:48 -0300
- Subject: [PATCH 6/6] Add malloc probes for sbrk and heap resizing.
- Authentication-results: sourceware.org; auth=none
- References: <523B05A1 dot 4060009 at redhat dot com>
for ChangeLog
* 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.
---
malloc/arena.c | 4 ++++
malloc/malloc.c | 6 +++++-
manual/probes.texi | 40 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+), 1 deletion(-)
diff --git a/malloc/arena.c b/malloc/arena.c
index 9ace186..d81ed0d 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -581,6 +581,7 @@ 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;
}
@@ -606,6 +607,7 @@ grow_heap(heap_info *h, long diff)
}
h->size = new_size;
+ LIBC_PROBE (memory_heap_more, 2, h, h->size);
return 0;
}
@@ -633,6 +635,7 @@ 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;
}
@@ -674,6 +677,7 @@ 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 */
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 5b4fcff..2938234 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -2448,8 +2448,10 @@ static void* sysmalloc(INTERNAL_SIZE_T nb, mstate av)
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. */
@@ -2747,6 +2749,8 @@ 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);
diff --git a/manual/probes.texi b/manual/probes.texi
index cb81011..a93532a 100644
--- a/manual/probes.texi
+++ b/manual/probes.texi
@@ -24,6 +24,46 @@ arguments.
These probes are designed to signal relatively unusual situations within
the virtual memory subsystem of @theglibc{}.
+@deftp Probe memory_sbrk_more (void *@var{$arg1}, size_t @var{$arg2})
+This probe is hit 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 hit after the main arena is shortened by calling
+@code{sbrk}. Argument @var{$arg1} is the size released by @code{sbrk}
+(the positive value, rather than the negated number passed to
+@code{sbrk}), and @var{$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 hit 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 hit before (unlike the other sbrk and heap probes) a heap
+is completely un@code{mmap}ped. Argument @var{$arg1} is a pointer to
+the heap, and @var{$arg2} is the size of the heap.
+@end deftp
+
+@deftp Probe memory_heap_less (void *@var{$arg1}, size_t @var{$arg2})
+This probe is hit 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_heap_more (void *@var{$arg1}, size_t @var{$arg2})
+This probe is hit 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_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})