Re: [PATCH perf/core v8 07/16] perf probe: Remove caches when --cache is given

[Masami Hiramatsu <mhiramat@kernel.org>]

On Thu, 19 May 2016 06:15:38 +0530
Hemant Kumar <hemant@linux.vnet.ibm.com> wrote:

> Hi Masami,
> 
> On 05/15/2016 08:50 AM, Masami Hiramatsu wrote:
> > From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> >
> > perf-probe --del removes caches when --cache is given.
> > Note that the delete pattern is not same as normal events.
> >
> > If you cached probes with event name, --del "eventname"
> > works as expected. However, if you skipped it, the cached
> > probes doesn't have actual event name. In that case
> >   --del "probe-desc" is required (wildcard is acceptable).
> > For example a cache entry has the probe-desc "vfs_read $params",
> > you can remove it with --del 'vfs_read*'.
> >
> >    -----
> >    # perf probe --cache --list
> >    /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
> >    vfs_read $params
> >    /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
> >    getaddrinfo $params
> >
> >    # perf probe --cache --del vfs_read\*
> >    Removed event: probe:vfs_read
> 
> Not sure where the o/p message for perf probe --cache --del
> is coming from here. So, if we are removing an event from the cache,
> is it intended to remove that from the {u,k}probe_events file as well?

No, it only deletes entries from the cache. No actual probes are
removed.

> The patch removes only from the cache (which I think is the intended
> behavior).  With this patch, when I delete an event from the cache, it
> silently deletes it. So, do we add some kind of a message there?

Ah, good point!

> # ./perf probe --cache --list
> [kernel.kallsyms] (818a8e96766649cb2b62fc0bc3e66c27be0cd870):
> vfs_read
> /usr/lib64/libc-2.18.so (e8587f5d2edba244cc43368b5ebfce1782195b6f):
> getaddrinfo $params
> 
> # ./perf probe --cache --del vfs_read\*
> #
> 
> If we are silently removing the events from the cache, the commit message
> needs to be ammended.

Hmm, it must be dropped while updating series...

OK, I'll fix it!

Thanks!

> 
> >    # perf probe --cache --list
> >    /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
> >    /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
> >    getaddrinfo $params
> >    -----
> >
> > Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> > ---
> >   Changes in v4:
> >    - move del_perf_probe_caches() into builtin-probe.c since
> >      command-line related delete procedure is there now.
> > ---
> >   tools/perf/Documentation/perf-probe.txt |    1 +
> >   tools/perf/builtin-probe.c              |   27 ++++++++++++++++++++++++++
> >   tools/perf/util/probe-file.c            |   32 ++++++++++++++++++++++++-------
> >   tools/perf/util/probe-file.h            |    2 ++
> >   4 files changed, 55 insertions(+), 7 deletions(-)
> >
> > diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
> > index 5a70d45..8d09173 100644
> > --- a/tools/perf/Documentation/perf-probe.txt
> > +++ b/tools/perf/Documentation/perf-probe.txt
> > @@ -116,6 +116,7 @@ OPTIONS
> >   	(With --add) Cache the probes. Any events which successfully added
> >   	are also stored in the cache file.
> >   	(With --list) Show cached probes.
> > +	(With --del) Remove cached probes.
> >
> >   --max-probes=NUM::
> >   	Set the maximum number of probe points for an event. Default is 128.
> > diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
> > index 53e380c0e..8f61525 100644
> > --- a/tools/perf/builtin-probe.c
> > +++ b/tools/perf/builtin-probe.c
> > @@ -363,6 +363,30 @@ out_cleanup:
> >   	return ret;
> >   }
> >
> > +static int del_perf_probe_caches(struct strfilter *filter)
> > +{
> > +	struct probe_cache *cache;
> > +	struct strlist *bidlist;
> > +	struct str_node *nd;
> > +	int ret;
> > +
> > +	ret = build_id_cache__list_all(&bidlist);
> > +	if (ret < 0) {
> > +		pr_debug("Failed to get buildids: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	strlist__for_each(nd, bidlist) {
> > +		cache = probe_cache__new(nd->s);
> > +		if (!cache)
> > +			continue;
> > +		probe_cache__remove_entries(cache, filter);
> > +		probe_cache__commit(cache);
> > +		probe_cache__delete(cache);
> > +	}
> > +	return 0;
> > +}
> > +
> >   static int perf_del_probe_events(struct strfilter *filter)
> >   {
> >   	int ret, ret2, ufd = -1, kfd = -1;
> > @@ -375,6 +399,9 @@ static int perf_del_probe_events(struct strfilter *filter)
> >
> >   	pr_debug("Delete filter: \'%s\'\n", str);
> >
> > +	if (probe_conf.cache)
> > +		return del_perf_probe_caches(filter);
> > +
> >   	/* Get current event names */
> >   	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
> >   	if (ret < 0)
> > diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
> > index a6d4a67..cc0f183 100644
> > --- a/tools/perf/util/probe-file.c
> > +++ b/tools/perf/util/probe-file.c
> > @@ -660,19 +660,37 @@ out:
> >   	return ret;
> >   }
> >
> > +static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
> > +				       struct strfilter *filter)
> > +{
> > +	char buf[128], *ptr = entry->spev;
> > +
> > +	if (entry->pev.event) {
> > +		snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
> > +		ptr = buf;
> > +	}
> > +	return strfilter__compare(filter, ptr);
> > +}
> > +
> > +int probe_cache__remove_entries(struct probe_cache *pcache,
> > +				struct strfilter *filter)
> > +{
> > +	struct probe_cache_entry *entry, *tmp;
> > +
> > +	list_for_each_entry_safe(entry, tmp, &pcache->list, list) {
> > +		if (probe_cache_entry__compare(entry, filter))
> > +			probe_cache_entry__delete(entry);
> > +	}
> > +	return 0;
> > +}
> > +
> >   static int probe_cache__show_entries(struct probe_cache *pcache,
> >   				     struct strfilter *filter)
> >   {
> >   	struct probe_cache_entry *entry;
> > -	char buf[128], *ptr;
> >
> >   	list_for_each_entry(entry, &pcache->list, list) {
> > -		if (entry->pev.event) {
> > -			ptr = buf;
> > -			snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
> > -		} else
> > -			ptr = entry->spev;
> > -		if (strfilter__compare(filter, ptr))
> > +		if (probe_cache_entry__compare(entry, filter))
> >   			printf("%s\n", entry->spev);
> >   	}
> >   	return 0;
> > diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h
> > index ac70446..e6fd9b9 100644
> > --- a/tools/perf/util/probe-file.h
> > +++ b/tools/perf/util/probe-file.h
> > @@ -37,6 +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);
> > +int probe_cache__remove_entries(struct probe_cache *pcache,
> > +				struct strfilter *filter);
> >   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,
> >
> 
> -- 
> Thanks,
> Hemant Kumar
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>