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[PATCH 1/6] Add first set of memory probes.
- 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 23:29:02 -0300
- Subject: [PATCH 1/6] Add first set of memory probes.
- Authentication-results: sourceware.org; auth=none
- References: <orob7o33xs dot fsf at livre dot home>
for ChangeLog
* 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/threads.texi: Set next node.
---
malloc/arena.c | 1 +
malloc/malloc.c | 4 ++++
manual/Makefile | 2 +-
manual/probes.texi | 41 +++++++++++++++++++++++++++++++++++++++++
manual/threads.texi | 2 +-
5 files changed, 48 insertions(+), 2 deletions(-)
create mode 100644 manual/probes.texi
diff --git a/malloc/arena.c b/malloc/arena.c
index 12a48ad..0822fc8 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -736,6 +736,7 @@ _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);
diff --git a/malloc/malloc.c b/malloc/malloc.c
index f7718a9..97ba34f 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -1878,6 +1878,8 @@ 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"
@@ -4695,6 +4697,8 @@ int __libc_mallopt(int param_number, int value)
/* 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) {
diff --git a/manual/Makefile b/manual/Makefile
index 44c0fd4..7bb419a 100644
--- a/manual/Makefile
+++ b/manual/Makefile
@@ -42,7 +42,7 @@ 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 threads)
+ users sysinfo conf crypt debug threads probes)
add-chapters = $(wildcard $(foreach d, $(add-ons), ../$d/$d.texi))
appendices = lang.texi header.texi install.texi maint.texi platform.texi \
contrib.texi
diff --git a/manual/probes.texi b/manual/probes.texi
new file mode 100644
index 0000000..fc02ffd
--- /dev/null
+++ b/manual/probes.texi
@@ -0,0 +1,41 @@
+@node Internal Probes
+@c @node Internal Probes, , POSIX Threads, Top
+@c %MENU% Probes to monitor libc internal behavior
+@chapter Internal probes
+
+In order to aid in debugging and monitoring internal behavior,
+@theglibc{} exposes nearly-zero-overhead SystemTap probes marked with
+the @code{libc} provider.
+
+These probes are not part of the @glibcadj{} stable ABI, and they are
+subject to change or removal across releases. Our only promise with
+regard to them is that, if we find a need to remove or modify the
+arguments of a probe, the modified probe will have a different name, so
+that program monitors relying on the old probe will not get unexpected
+arguments.
+
+@menu
+* Memory Allocation Probes:: Probes in the memory allocation subsystem
+@end menu
+
+@node Memory Allocation Probes
+@section Memory Allocation Probes
+
+These probes are designed to signal relatively unusual situations within
+the virtual memory subsystem of @theglibc{}.
+
+@deftp Probe memory_arena_new (void *@var{$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{$arg2} bytes.
+@end deftp
+
+@deftp Probe memory_mallopt (int @var{$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
diff --git a/manual/threads.texi b/manual/threads.texi
index a23ac26..6b7523c 100644
--- a/manual/threads.texi
+++ b/manual/threads.texi
@@ -1,5 +1,5 @@
@node POSIX Threads
-@c @node POSIX Threads, , Cryptographic Functions, Top
+@c @node POSIX Threads, Intenal Probes, Cryptographic Functions, Top
@chapter POSIX Threads
@c %MENU% POSIX Threads
@cindex pthreads