[PATCH v8 6/6] perf probe: Support SDT markers having reference counter (semaphore)
With this, perf buildid-cache will save SDT markers with reference
counter in probe cache. Perf probe will be able to probe markers
having reference counter. Ex,
# readelf -n /tmp/tick | grep -A1 loop2
Name: loop2
... Semaphore: 0x10020036
# ./perf buildid-cache --add /tmp/tick
# ./perf probe sdt_tick:loop2
# ./perf stat -e sdt_tick:loop2 /tmp/tick
hi: 0
hi: 1
hi: 2
^C
Performance counter stats for '/tmp/tick':
3 sdt_tick:loop2
2.561851452 seconds time elapsed
Signed-off-by: Ravi Bangoria
Acked-by: Masami Hiramatsu
Acked-by: Srikar Dronamraju
---
tools/perf/util/probe-event.c | 39
tools/perf/util/probe-event.h | 1 +
tools/perf/util/probe-file.c | 34 ++--
tools/perf/util/probe-file.h | 1 +
tools/perf/util/symbol-elf.c | 46 ---
tools/perf/util/symbol.h | 7 +++
6 files changed, 106 insertions(+), 22 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f119eb628dbb..e86f8be89157 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1819,6 +1819,12 @@ int parse_probe_trace_command(const char *cmd, struct
probe_trace_event *tev)
tp->offset = strtoul(fmt2_str, NULL, 10);
}
+ if (tev->uprobes) {
+ fmt2_str = strchr(p, '(');
+ if (fmt2_str)
+ tp->ref_ctr_offset = strtoul(fmt2_str + 1, NULL, 0);
+ }
+
tev->nargs = argc - 2;
tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
if (tev->args == NULL) {
@@ -2012,6 +2018,22 @@ static int synthesize_probe_trace_arg(struct
probe_trace_arg *arg,
return err;
}
+static int
+synthesize_uprobe_trace_def(struct probe_trace_event *tev, struct strbuf *buf)
+{
+ struct probe_trace_point *tp = >point;
+ int err;
+
+ err = strbuf_addf(buf, "%s:0x%lx", tp->module, tp->address);
+
+ if (err >= 0 && tp->ref_ctr_offset) {
+ if (!uprobe_ref_ctr_is_supported())
+ return -1;
+ err = strbuf_addf(buf, "(0x%lx)", tp->ref_ctr_offset);
+ }
+ return err >= 0 ? 0 : -1;
+}
+
char *synthesize_probe_trace_command(struct probe_trace_event *tev)
{
struct probe_trace_point *tp = >point;
@@ -2041,15 +2063,17 @@ char *synthesize_probe_trace_command(struct
probe_trace_event *tev)
}
/* Use the tp->address for uprobes */
- if (tev->uprobes)
- err = strbuf_addf(, "%s:0x%lx", tp->module, tp->address);
- else if (!strncmp(tp->symbol, "0x", 2))
+ if (tev->uprobes) {
+ err = synthesize_uprobe_trace_def(tev, );
+ } else if (!strncmp(tp->symbol, "0x", 2)) {
/* Absolute address. See try_to_find_absolute_address() */
err = strbuf_addf(, "%s%s0x%lx", tp->module ?: "",
tp->module ? ":" : "", tp->address);
- else
+ } else {
err = strbuf_addf(, "%s%s%s+%lu", tp->module ?: "",
tp->module ? ":" : "", tp->symbol, tp->offset);
+ }
+
if (err)
goto error;
@@ -2633,6 +2657,13 @@ static void warn_uprobe_event_compat(struct
probe_trace_event *tev)
{
int i;
char *buf = synthesize_probe_trace_command(tev);
+ struct probe_trace_point *tp = >point;
+
+ if (tp->ref_ctr_offset && !uprobe_ref_ctr_is_supported()) {
+ pr_warning("A semaphore is associated with %s:%s and "
+ "seems your kernel doesn't support it.\n",
+ tev->group, tev->event);
+ }
/* Old uprobe event doesn't support memory dereference */
if (!tev->uprobes || tev->nargs == 0 || !buf)
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 45b14f020558..15a98c3a2a2f 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -27,6 +27,7 @@ struct probe_trace_point {
char*symbol;/* Base symbol */
char*module;/* Module name */
unsigned long offset; /* Offset from symbol */
+ unsigned long ref_ctr_offset; /* SDT reference counter offset */
unsigned long address;/* Actual address of the trace point */
boolretprobe; /* Return probe flag */
};
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index b76088fadf3d..aac7817d9e14 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -696,8 +696,16 @@ int probe_cache__add_entry(struct probe_cache *pcache,
#ifdef HAVE_GELF_GETNOTE_SUPPORT
static unsigned long long sdt_note__get_addr(struct sdt_note *note)
{
- return note->bit32 ? (unsigned long
[PATCH v8 6/6] perf probe: Support SDT markers having reference counter (semaphore)
With this, perf buildid-cache will save SDT markers with reference
counter in probe cache. Perf probe will be able to probe markers
having reference counter. Ex,
# readelf -n /tmp/tick | grep -A1 loop2
Name: loop2
... Semaphore: 0x10020036
# ./perf buildid-cache --add /tmp/tick
# ./perf probe sdt_tick:loop2
# ./perf stat -e sdt_tick:loop2 /tmp/tick
hi: 0
hi: 1
hi: 2
^C
Performance counter stats for '/tmp/tick':
3 sdt_tick:loop2
2.561851452 seconds time elapsed
Signed-off-by: Ravi Bangoria
Acked-by: Masami Hiramatsu
Acked-by: Srikar Dronamraju
---
tools/perf/util/probe-event.c | 39
tools/perf/util/probe-event.h | 1 +
tools/perf/util/probe-file.c | 34 ++--
tools/perf/util/probe-file.h | 1 +
tools/perf/util/symbol-elf.c | 46 ---
tools/perf/util/symbol.h | 7 +++
6 files changed, 106 insertions(+), 22 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f119eb628dbb..e86f8be89157 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1819,6 +1819,12 @@ int parse_probe_trace_command(const char *cmd, struct
probe_trace_event *tev)
tp->offset = strtoul(fmt2_str, NULL, 10);
}
+ if (tev->uprobes) {
+ fmt2_str = strchr(p, '(');
+ if (fmt2_str)
+ tp->ref_ctr_offset = strtoul(fmt2_str + 1, NULL, 0);
+ }
+
tev->nargs = argc - 2;
tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
if (tev->args == NULL) {
@@ -2012,6 +2018,22 @@ static int synthesize_probe_trace_arg(struct
probe_trace_arg *arg,
return err;
}
+static int
+synthesize_uprobe_trace_def(struct probe_trace_event *tev, struct strbuf *buf)
+{
+ struct probe_trace_point *tp = >point;
+ int err;
+
+ err = strbuf_addf(buf, "%s:0x%lx", tp->module, tp->address);
+
+ if (err >= 0 && tp->ref_ctr_offset) {
+ if (!uprobe_ref_ctr_is_supported())
+ return -1;
+ err = strbuf_addf(buf, "(0x%lx)", tp->ref_ctr_offset);
+ }
+ return err >= 0 ? 0 : -1;
+}
+
char *synthesize_probe_trace_command(struct probe_trace_event *tev)
{
struct probe_trace_point *tp = >point;
@@ -2041,15 +2063,17 @@ char *synthesize_probe_trace_command(struct
probe_trace_event *tev)
}
/* Use the tp->address for uprobes */
- if (tev->uprobes)
- err = strbuf_addf(, "%s:0x%lx", tp->module, tp->address);
- else if (!strncmp(tp->symbol, "0x", 2))
+ if (tev->uprobes) {
+ err = synthesize_uprobe_trace_def(tev, );
+ } else if (!strncmp(tp->symbol, "0x", 2)) {
/* Absolute address. See try_to_find_absolute_address() */
err = strbuf_addf(, "%s%s0x%lx", tp->module ?: "",
tp->module ? ":" : "", tp->address);
- else
+ } else {
err = strbuf_addf(, "%s%s%s+%lu", tp->module ?: "",
tp->module ? ":" : "", tp->symbol, tp->offset);
+ }
+
if (err)
goto error;
@@ -2633,6 +2657,13 @@ static void warn_uprobe_event_compat(struct
probe_trace_event *tev)
{
int i;
char *buf = synthesize_probe_trace_command(tev);
+ struct probe_trace_point *tp = >point;
+
+ if (tp->ref_ctr_offset && !uprobe_ref_ctr_is_supported()) {
+ pr_warning("A semaphore is associated with %s:%s and "
+ "seems your kernel doesn't support it.\n",
+ tev->group, tev->event);
+ }
/* Old uprobe event doesn't support memory dereference */
if (!tev->uprobes || tev->nargs == 0 || !buf)
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 45b14f020558..15a98c3a2a2f 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -27,6 +27,7 @@ struct probe_trace_point {
char*symbol;/* Base symbol */
char*module;/* Module name */
unsigned long offset; /* Offset from symbol */
+ unsigned long ref_ctr_offset; /* SDT reference counter offset */
unsigned long address;/* Actual address of the trace point */
boolretprobe; /* Return probe flag */
};
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index b76088fadf3d..aac7817d9e14 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -696,8 +696,16 @@ int probe_cache__add_entry(struct probe_cache *pcache,
#ifdef HAVE_GELF_GETNOTE_SUPPORT
static unsigned long long sdt_note__get_addr(struct sdt_note *note)
{
- return note->bit32 ? (unsigned long
