perf probe: Use cache entry if possible

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 <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146736019226.27797.16366402884098398857.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 86 insertions, 4 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 55f41d5e20d1..47b6b8b7206e 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2474,17 +2474,24 @@ 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;
 
@@ -2531,7 +2538,7 @@ 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) */
@@ -2844,6 +2851,55 @@ 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_entry(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)
 {
@@ -2866,6 +2922,11 @@ 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 1c12c1ab19c9..a94ee478178d 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -524,7 +524,7 @@ 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;
@@ -548,6 +548,24 @@ 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->entries, node) {
+                /* 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 d872e3df7e59..910aa74953e9 100644
--- a/tools/perf/util/probe-file.h
+++ b/tools/perf/util/probe-file.h
@@ -38,5 +38,8 @@ int probe_cache__add_entry(struct probe_cache *pcache,
 int probe_cache__commit(struct probe_cache *pcache);
 void probe_cache__purge(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