On Fri, 1 Jul 2016 15:22:01 -0300
Arnaldo Carvalho de Melo <a...@kernel.org> wrote:
> Em Fri, Jul 01, 2016 at 05:04:10PM +0900, Masami Hiramatsu escreveu:
> > From: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
> >
> > perf buildid-cache --add <binary> scans given binary and add
> > the SDT events to probe cache. "sdt_" prefix is appended for
> > all SDT providers to avoid event-name clash with other pre-defined
> > events. It is possible to use the cached SDT events as other cached
> > events, via perf probe --add "sdt_<provider>:<event>=<event>".
> >
> > e.g.
> > ----
> > # perf buildid-cache --add /lib/libc-2.17.so
> > # perf probe --cache --list | head -n 5
> > /usr/lib/libc-2.17.so (a6fb821bdf53660eb2c29f778757aef294d3d392):
> > sdt_libc:setjmp=setjmp
> > sdt_libc:longjmp=longjmp
> > sdt_libc:longjmp_target=longjmp_target
> > sdt_libc:memory_heap_new=memory_heap_new
> > # perf probe -x /usr/lib/libc-2.17.so \
> > -a sdt_libc:memory_heap_new=memory_heap_new
>
> Why not remove the need for that build-cache --add? I.e. go straight to:
>
> perf probe -x /usr/lib/libc-2.17.so -a
> sdt_libc:memory_heap_new=memory_heap_new
>
> And all the various steps above be done automagically?
Yes, I can add that.
> It may well be interesting to have it available as separate steps, as above,
> but requiring this cumbersome sequence to performed all the time when it seems
> possible to do automatically seems user unfriendly.
Agreed. In 11/15 added a feature to search SDT without -x, but
usually uprobes requires -x, using -x is also natural.
>
> I am tentatively applying this and testing.
Thank you!
>
> - Arnaldo
>
> > Added new event:
> > sdt_libc:memory_heap_new (on memory_heap_new
> > in /usr/lib/libc-2.17.so)
> >
> > You can now use it in all perf tools, such as:
> >
> > perf record -e sdt_libc:memory_heap_new -aR sleep 1
> >
> > # perf probe -l
> > sdt_libc:memory_heap_new (on new_heap+183 in /usr/lib/libc-2.17.so)
> > ----
> >
> > Note that SDT event entries in probe-cache file is somewhat different
> > from normal cached events. Normal one starts with "#", but SDTs are
> > starting with "%".
>
> Is this still the case?
>
> [root@jouet perf]# perf probe --cache --list
> /usr/lib64/libc-2.23.so (88686319c72f1a9d9cd514af519aa5602880bab2):
> sdt_libc:setjmp=setjmp
> sdt_libc:longjmp=longjmp
> sdt_libc:longjmp_target=longjmp_target
> sdt_libc:memory_arena_reuse_free_list=memory_arena_reuse_free_list
> sdt_libc:memory_heap_new=memory_heap_new
> sdt_libc:memory_sbrk_less=memory_sbrk_less
> sdt_libc:memory_arena_reuse_wait=memory_arena_reuse_wait
> sdt_libc:memory_arena_reuse=memory_arena_reuse
> sdt_libc:memory_arena_new=memory_arena_new
> sdt_libc:memory_arena_retry=memory_arena_retry
> sdt_libc:memory_heap_free=memory_heap_free
> sdt_libc:memory_heap_less=memory_heap_less
> sdt_libc:memory_heap_more=memory_heap_more
> sdt_libc:memory_sbrk_more=memory_sbrk_more
> sdt_libc:memory_malloc_retry=memory_malloc_retry
> sdt_libc:memory_mallopt_free_dyn_thresholds=memory_mallopt_free_dyn_thresholds
> sdt_libc:memory_realloc_retry=memory_realloc_retry
> sdt_libc:memory_memalign_retry=memory_memalign_retry
> sdt_libc:memory_calloc_retry=memory_calloc_retry
> sdt_libc:memory_mallopt=memory_mallopt
> sdt_libc:memory_mallopt_mxfast=memory_mallopt_mxfast
> sdt_libc:memory_mallopt_arena_max=memory_mallopt_arena_max
> sdt_libc:memory_mallopt_arena_test=memory_mallopt_arena_test
> sdt_libc:memory_mallopt_mmap_max=memory_mallopt_mmap_max
> sdt_libc:memory_mallopt_mmap_threshold=memory_mallopt_mmap_threshold
> sdt_libc:memory_mallopt_top_pad=memory_mallopt_top_pad
> sdt_libc:memory_mallopt_trim_threshold=memory_mallopt_trim_threshold
> sdt_libc:memory_mallopt_perturb=memory_mallopt_perturb
> sdt_libc:memory_mallopt_check_action=memory_mallopt_check_action
> sdt_libc:lll_lock_wait_private=lll_lock_wait_private
> [root@jouet perf]#
>
>
>
> > Signed-off-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
> > Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
> > ---
> > Changes in v11:
> > - Warn if SDT scanning/updating are failed.
> > Changes in v10:
> > - Update Documentation/perf-buildid-cache.txt too.
> > Changes in v4:
> > - Fix a bug to copy correct group name to entries.
> > - Fix to consolidate same-name entries.
> > ---
> > tools/perf/Documentation/perf-buildid-cache.txt | 3 +
> > tools/perf/util/build-id.c | 30 ++++++++++
> > tools/perf/util/probe-file.c | 69
> > ++++++++++++++++++++++-
> > tools/perf/util/probe-file.h | 2 +
> > 4 files changed, 101 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/Documentation/perf-buildid-cache.txt
> > b/tools/perf/Documentation/perf-buildid-cache.txt
> > index dd07b55..058064d 100644
> > --- a/tools/perf/Documentation/perf-buildid-cache.txt
> > +++ b/tools/perf/Documentation/perf-buildid-cache.txt
> > @@ -15,6 +15,9 @@ DESCRIPTION
> > This command manages the build-id cache. It can add, remove, update and
> > purge
> > files to/from the cache. In the future it should as well set upper limits
> > for
> > the space used by the cache, etc.
> > +This also scans the target binary for SDT (Statically Defined Tracing) and
> > +record it along with the buildid-cache, which will be used by perf-probe.
> > +For more details, see linkperf:perf-probe[1].
> >
> > OPTIONS
> > -------
> > diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> > index 1c49620..e1a1640 100644
> > --- a/tools/perf/util/build-id.c
> > +++ b/tools/perf/util/build-id.c
> > @@ -17,6 +17,7 @@
> > #include "tool.h"
> > #include "header.h"
> > #include "vdso.h"
> > +#include "probe-file.h"
> >
> >
> > static bool no_buildid_cache;
> > @@ -532,6 +533,30 @@ int build_id_cache__list_build_ids(const char
> > *pathname,
> > return ret;
> > }
> >
> > +#ifdef HAVE_LIBELF_SUPPORT
> > +static int build_id_cache__add_sdt_cache(const char *sbuild_id,
> > + const char *realname)
> > +{
> > + struct probe_cache *cache;
> > + int ret;
> > +
> > + cache = probe_cache__new(sbuild_id);
> > + if (!cache)
> > + return -1;
> > +
> > + ret = probe_cache__scan_sdt(cache, realname);
> > + if (ret >= 0) {
> > + pr_debug("Found %d SDTs in %s\n", ret, realname);
> > + if (probe_cache__commit(cache) < 0)
> > + ret = -1;
> > + }
> > + probe_cache__delete(cache);
> > + return ret;
> > +}
> > +#else
> > +#define build_id_cache__add_sdt_cache(sbuild_id, realname) (0)
> > +#endif
> > +
> > int build_id_cache__add_s(const char *sbuild_id, const char *name,
> > bool is_kallsyms, bool is_vdso)
> > {
> > @@ -589,6 +614,11 @@ int build_id_cache__add_s(const char *sbuild_id, const
> > char *name,
> >
> > if (symlink(tmp, linkname) == 0)
> > err = 0;
> > +
> > + /* Update SDT cache : error is just warned */
> > + if (build_id_cache__add_sdt_cache(sbuild_id, realname) < 0)
> > + pr_debug("Failed to update/scan SDT cache for %s\n", realname);
> > +
> > out_free:
> > if (!is_kallsyms)
> > free(realname);
> > diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
> > index 6cb6ec0..5b563b2 100644
> > --- a/tools/perf/util/probe-file.c
> > +++ b/tools/perf/util/probe-file.c
> > @@ -434,12 +434,15 @@ static int probe_cache__load(struct probe_cache
> > *pcache)
> > p = strchr(buf, '\n');
> > if (p)
> > *p = '\0';
> > - if (buf[0] == '#') { /* #perf_probe_event */
> > + /* #perf_probe_event or %sdt_event */
> > + if (buf[0] == '#' || buf[0] == '%') {
> > entry = probe_cache_entry__new(NULL);
> > if (!entry) {
> > ret = -ENOMEM;
> > goto out;
> > }
> > + if (buf[0] == '%')
> > + entry->sdt = true;
> > entry->spev = strdup(buf + 1);
> > if (entry->spev)
> > ret = parse_perf_probe_command(buf + 1,
> > @@ -621,19 +624,79 @@ out_err:
> > return ret;
> > }
> >
> > +static unsigned long long sdt_note__get_addr(struct sdt_note *note)
> > +{
> > + return note->bit32 ? (unsigned long long)note->addr.a32[0]
> > + : (unsigned long long)note->addr.a64[0];
> > +}
> > +
> > +int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
> > +{
> > + struct probe_cache_entry *entry = NULL;
> > + struct list_head sdtlist;
> > + struct sdt_note *note;
> > + char *buf;
> > + char sdtgrp[64];
> > + int ret;
> > +
> > + INIT_LIST_HEAD(&sdtlist);
> > + ret = get_sdt_note_list(&sdtlist, pathname);
> > + if (ret < 0) {
> > + pr_debug("Failed to get sdt note: %d\n", ret);
> > + return ret;
> > + }
> > + list_for_each_entry(note, &sdtlist, note_list) {
> > + ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
> > + if (ret < 0)
> > + break;
> > + /* Try to find same-name entry */
> > + entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
> > + if (!entry) {
> > + entry = probe_cache_entry__new(NULL);
> > + if (!entry) {
> > + ret = -ENOMEM;
> > + break;
> > + }
> > + entry->sdt = true;
> > + ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
> > + note->name, note->name);
> > + if (ret < 0)
> > + break;
> > + entry->pev.event = strdup(note->name);
> > + entry->pev.group = strdup(sdtgrp);
> > + list_add_tail(&entry->node, &pcache->entries);
> > + }
> > + ret = asprintf(&buf, "p:%s/%s %s:0x%llx",
> > + sdtgrp, note->name, pathname,
> > + sdt_note__get_addr(note));
> > + if (ret < 0)
> > + break;
> > + strlist__add(entry->tevlist, buf);
> > + free(buf);
> > + entry = NULL;
> > + }
> > + if (entry) {
> > + list_del_init(&entry->node);
> > + probe_cache_entry__delete(entry);
> > + }
> > + cleanup_sdt_note_list(&sdtlist);
> > + return ret;
> > +}
> > +
> > static int probe_cache_entry__write(struct probe_cache_entry *entry, int
> > fd)
> > {
> > struct str_node *snode;
> > struct stat st;
> > struct iovec iov[3];
> > + const char *prefix = entry->sdt ? "%" : "#";
> > int ret;
> > /* Save stat for rollback */
> > ret = fstat(fd, &st);
> > if (ret < 0)
> > return ret;
> >
> > - pr_debug("Writing cache: #%s\n", entry->spev);
> > - iov[0].iov_base = (void *)"#"; iov[0].iov_len = 1;
> > + pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
> > + iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
> > iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
> > iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
> > ret = writev(fd, iov, 3);
> > diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h
> > index 0ed1fc5..ddf5ae2 100644
> > --- a/tools/perf/util/probe-file.h
> > +++ b/tools/perf/util/probe-file.h
> > @@ -8,6 +8,7 @@
> > /* Cache of probe definitions */
> > struct probe_cache_entry {
> > struct list_head node;
> > + bool sdt;
> > struct perf_probe_event pev;
> > char *spev;
> > struct strlist *tevlist;
> > @@ -35,6 +36,7 @@ struct probe_cache *probe_cache__new(const char *target);
> > int probe_cache__add_entry(struct probe_cache *pcache,
> > struct perf_probe_event *pev,
> > struct probe_trace_event *tevs, int ntevs);
> > +int probe_cache__scan_sdt(struct probe_cache *pcache, const char
> > *pathname);
> > int probe_cache__commit(struct probe_cache *pcache);
> > void probe_cache__purge(struct probe_cache *pcache);
> > void probe_cache__delete(struct probe_cache *pcache);
--
Masami Hiramatsu <mhira...@kernel.org>
