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    Subject[PATCH perf/core v12 01/16] 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 v12:
    - Rename strlist__for_each to strlist__for_each_entry.

    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 55f41d5..47b6b8b 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 1c12c1a..a94ee47 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 d872e3d..910aa74 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
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