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perf probe: Use cache entry if possible
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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>
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@mhiramathitachi @acmel
mhiramathitachi authored and acmel committed Jul 1, 2016
1 parent dc29bb4 commit bc06223
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Showing 3 changed files with 86 additions and 4 deletions.
65 changes: 63 additions & 2 deletions tools/perf/util/probe-event.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;

Expand Down Expand Up @@ -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) */
Expand Down Expand Up @@ -2844,6 +2851,55 @@ static int try_to_find_absolute_address(struct perf_probe_event *pev,

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)
{
Expand All @@ -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)
Expand Down
20 changes: 19 additions & 1 deletion tools/perf/util/probe-file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -548,6 +548,24 @@ probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
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)
Expand Down
5 changes: 4 additions & 1 deletion tools/perf/util/probe-file.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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

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