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Subject[PATCH perf/core v9 05/16] perf probe: Use cache entry if possible
Date
From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Before analyzing debuginfo, try to find a corresponding entry
from probe cache always. This does not depend on --cache,
the --cache enables to store/update cache, but looking up
the cache is always enabled.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
Changes in v6:
- Remove fallback lookup routine by using function name
as cached event name, because it should be done by following
patch which supports %cached-event.
---
tools/perf/util/probe-event.c | 65 ++++++++++++++++++++++++++++++++++++++++-
tools/perf/util/probe-file.c | 20 ++++++++++++-
tools/perf/util/probe-file.h | 5 +++
3 files changed, 86 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 854885b..acc8341 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2472,17 +2472,24 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev,
char buf[64];
int ret;

+ /* If probe_event or trace_event already have the name, reuse it */
if (pev->event)
event = pev->event;
- else
+ else if (tev->event)
+ event = tev->event;
+ else {
+ /* Or generate new one from probe point */
if (pev->point.function &&
(strncmp(pev->point.function, "0x", 2) != 0) &&
!strisglob(pev->point.function))
event = pev->point.function;
else
event = tev->point.realname;
+ }
if (pev->group)
group = pev->group;
+ else if (tev->group)
+ group = tev->group;
else
group = PERFPROBE_GROUP;

@@ -2529,7 +2536,7 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
for (i = 0; i < ntevs; i++) {
tev = &tevs[i];
/* Skip if the symbol is out of .text or blacklisted */
- if (!tev->point.symbol)
+ if (!tev->point.symbol && !pev->uprobes)
continue;

/* Set new name for tev (and update namelist) */
@@ -2842,6 +2849,55 @@ errout:

bool __weak arch__prefers_symtab(void) { return false; }

+static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
+ struct probe_trace_event **tevs)
+{
+ struct probe_cache *cache;
+ struct probe_cache_entry *entry;
+ struct probe_trace_event *tev;
+ struct str_node *node;
+ int ret, i;
+
+ cache = probe_cache__new(pev->target);
+ if (!cache)
+ return 0;
+
+ entry = probe_cache__find(cache, pev);
+ if (!entry) {
+ ret = 0;
+ goto out;
+ }
+
+ ret = strlist__nr_entries(entry->tevlist);
+ if (ret > probe_conf.max_probes) {
+ pr_debug("Too many entries matched in the cache of %s\n",
+ pev->target ? : "kernel");
+ ret = -E2BIG;
+ goto out;
+ }
+
+ *tevs = zalloc(ret * sizeof(*tev));
+ if (!*tevs) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ i = 0;
+ strlist__for_each(node, entry->tevlist) {
+ tev = &(*tevs)[i++];
+ ret = parse_probe_trace_command(node->s, tev);
+ if (ret < 0)
+ goto out;
+ /* Set the uprobes attribute as same as original */
+ tev->uprobes = pev->uprobes;
+ }
+ ret = i;
+
+out:
+ probe_cache__delete(cache);
+ return ret;
+}
+
static int convert_to_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event **tevs)
{
@@ -2864,6 +2920,11 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev,
if (ret > 0)
return ret;

+ /* At first, we need to lookup cache entry */
+ ret = find_probe_trace_events_from_cache(pev, tevs);
+ if (ret > 0)
+ return ret; /* Found in probe cache */
+
if (arch__prefers_symtab() && !perf_probe_event_need_dwarf(pev)) {
ret = find_probe_trace_events_from_map(pev, tevs);
if (ret > 0)
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 689d874..f30f609 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -514,7 +514,7 @@ static bool streql(const char *a, const char *b)
return !strcmp(a, b);
}

-static struct probe_cache_entry *
+struct probe_cache_entry *
probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
{
struct probe_cache_entry *entry = NULL;
@@ -539,6 +539,24 @@ found:
return entry;
}

+struct probe_cache_entry *
+probe_cache__find_by_name(struct probe_cache *pcache,
+ const char *group, const char *event)
+{
+ struct probe_cache_entry *entry = NULL;
+
+ list_for_each_entry(entry, &pcache->list, list) {
+ /* Hit if same event name or same command-string */
+ if (streql(entry->pev.group, group) &&
+ streql(entry->pev.event, event))
+ goto found;
+ }
+ entry = NULL;
+
+found:
+ return entry;
+}
+
int probe_cache__add_entry(struct probe_cache *pcache,
struct perf_probe_event *pev,
struct probe_trace_event *tevs, int ntevs)
diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h
index d2b8791d..1385c8b 100644
--- a/tools/perf/util/probe-file.h
+++ b/tools/perf/util/probe-file.h
@@ -37,5 +37,8 @@ int probe_cache__add_entry(struct probe_cache *pcache,
struct probe_trace_event *tevs, int ntevs);
int probe_cache__commit(struct probe_cache *pcache);
void probe_cache__delete(struct probe_cache *pcache);
-
+struct probe_cache_entry *probe_cache__find(struct probe_cache *pcache,
+ struct perf_probe_event *pev);
+struct probe_cache_entry *probe_cache__find_by_name(struct probe_cache *pcache,
+ const char *group, const char *event);
#endif
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