[GIT PULL 0/3] perf/urgent fixes

[GIT PULL 0/3] perf/urgent fixes

[Arnaldo Carvalho de Melo]

Hi Ingo,

	Please consider pulling,

- Arnaldo

The following changes since commit 662f5cedb38c4b88e1cebfd54a88159f2f7ab7b9:

  Merge branch 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent (2012-06-24 19:08:49 +0200)

are available in the git repository at:


  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux tags/perf-urgent-for-mingo

for you to fetch changes up to 7ed97ad41ffa94040dfd593948962a7e9e7b0db9:

  perf kvm: Fix segfault with report and mixed guestmount use (2012-07-02 14:03:50 -0300)

----------------------------------------------------------------
perf/urgent fixes:

. Fix creation of guest machine objects when build ids are disabled,
  from David Ahern

. The kvm tool was trying to access an uninitialized guestmount variable, fix
  from David Ahern.

. Restore perf script output to pre-libparseevent merge format, removing
  duplicated info, fix from David Ahern

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

----------------------------------------------------------------
David Ahern (3):
      perf script: Fix format regression due to libtraceevent merge
      perf kvm: Fix regression with guest machine creation
      perf kvm: Fix segfault with report and mixed guestmount use

 tools/perf/util/map.c               |   29 +++++++++++++++--------------
 tools/perf/util/session.c           |    2 +-
 tools/perf/util/trace-event-parse.c |    3 +--
 3 files changed, 17 insertions(+), 17 deletions(-)

[PATCH 1/3] perf script: Fix format regression due to libtraceevent merge

[Arnaldo Carvalho de Melo]

From: David Ahern <dsahern@gmail.com>

Consider the commands:
    perf record -e sched:sched_switch -fo /tmp/perf.data  -a -- sleep 1
    perf script -i /tmp/perf.data

In v3.4 the output has the form (lines wrapped here)
    perf 29214 [005] 821043.582596: sched_switch:
prev_comm=perf prev_pid=29214 prev_prio=120
prev_state=S ==> next_comm=swapper/5 next_pid=0 next_prio=120

In 3.5 that same line has become:
    perf 29214 [005] 821043.582596: sched_switch:
<...>-29214 [005]     0.000000000: sched_switch:
prev_comm=perf prev_pid=29214 prev_prio=120
prev_state=S ==> next_comm=swapper/5 next_pid=0 next_prio=120

Note the duplicates in the output -- pid, cpu, event name. With
this patch the v3.4 output is restored:
    perf 29214 [005] 821043.582596: sched_switch:
prev_comm=perf prev_pid=29214 prev_prio=120
prev_state=S ==> next_comm=swapper/5 next_pid=0 next_prio=120

v3:
Remove that pesky newline too. Output now matches v3.4 (pre-libtracevent).

v2:
Change print_trace_event function local to perf per Steve's comments.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1339698977-68962-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/trace-event-parse.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index df2fddb..5dd3b5e 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -198,9 +198,8 @@ void print_trace_event(int cpu, void *data, int size)
 	record.data = data;
 
 	trace_seq_init(&s);
-	pevent_print_event(pevent, &s, &record);
+	pevent_event_info(&s, event, &record);
 	trace_seq_do_printf(&s);
-	printf("\n");
 }
 
 void print_event(int cpu, void *data, int size, unsigned long long nsecs,
-- 
1.7.1

[PATCH 2/3] perf kvm: Fix regression with guest machine creation

[Arnaldo Carvalho de Melo]

From: David Ahern <dsahern@gmail.com>

Commit 743eb868657bdb1b26c7b24077ca21c67c82c777 reworked when the
machines were created. Prior to this commit guest machines could be
created in perf_event__process_kernel_mmap() while processing kernel
MMAP events. This commit assumes that the machines exist by the time
perf_session_deliver_event is called (e.g., during processing of build
id events) - which is not always correct.

One example is the use of default guest args (--guestkallsyms and
--guestmodules) for short times where no samples hit within a guest
module. For this case no build id is added to the file header. No build
id == no machine created. That leads to the next example -- the use of
no-buildid (-B) on the record for all perf-kvm invocations. In both
cases perf report dies with a SEGFAULT of the form:

(gdb) bt
0  0x000000000046dd7b in machine__mmap_name (self=0x0, bf=0x7fffffffbd20 "q\021", size=4096) at util/map.c:715
1  0x0000000000444161 in perf_event__process_kernel_mmap (tool=0x7fffffffdd80, event=0x7ffff7fb4120, machine=0x0) at util/event.c:562
2  0x0000000000444642 in perf_event__process_mmap (tool=0x7fffffffdd80, event=0x7ffff7fb4120, sample=0x7fffffffd210, machine=0x0)
    at util/event.c:668
3  0x0000000000470e0b in perf_session_deliver_event (session=0x915ca0, event=0x7ffff7fb4120, sample=0x7fffffffd210, tool=0x7fffffffdd80,
    file_offset=8480) at util/session.c:979
4  0x000000000047032e in flush_sample_queue (s=0x915ca0, tool=0x7fffffffdd80) at util/session.c:679
5  0x0000000000471c8d in __perf_session__process_events (session=0x915ca0, data_offset=400, data_size=150448, file_size=150848, tool=
    0x7fffffffdd80) at util/session.c:1363
6  0x0000000000471d42 in perf_session__process_events (self=0x915ca0, tool=0x7fffffffdd80) at util/session.c:1379
7  0x000000000042484a in __cmd_report (rep=0x7fffffffdd80) at builtin-report.c:368
8  0x0000000000425bf1 in cmd_report (argc=0, argv=0x915b00, prefix=0x0) at builtin-report.c:756
9  0x0000000000438505 in __cmd_report (argc=4, argv=0x7fffffffe260) at builtin-kvm.c:84
10 0x000000000043882a in cmd_kvm (argc=4, argv=0x7fffffffe260, prefix=0x0) at builtin-kvm.c:131
11 0x00000000004152cd in run_builtin (p=0x7a54e8, argc=9, argv=0x7fffffffe260) at perf.c:273
12 0x00000000004154c7 in handle_internal_command (argc=9, argv=0x7fffffffe260) at perf.c:345
13 0x0000000000415613 in run_argv (argcp=0x7fffffffe14c, argv=0x7fffffffe140) at perf.c:389
14 0x0000000000415899 in main (argc=9, argv=0x7fffffffe260) at perf.c:487

Fix by allowing the machine to be created in perf_session_deliver_event.

Tested with --guestmount option and default guest args, with and without
-B arg on record for both and for short (10 seconds) and long (10
minutes) windows.

Reported-by: Pradeep Kumar Surisetty <psuriset@linux.vnet.ibm.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pradeep Kumar Surisetty <psuriset@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1341180697-64515-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/session.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index c3e399b..56142d0 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -926,7 +926,7 @@ static struct machine *
 		else
 			pid = event->ip.pid;
 
-		return perf_session__find_machine(session, pid);
+		return perf_session__findnew_machine(session, pid);
 	}
 
 	return perf_session__find_host_machine(session);
-- 
1.7.1

[PATCH 3/3] perf kvm: Fix segfault with report and mixed guestmount use

[Arnaldo Carvalho de Melo]

From: David Ahern <dsahern@gmail.com>

Using the guestmount option on record:
    $ perf kvm --guest --host --guestmount=/tmp/guest-mount record -ag

But not the subsequent report:
    $ perf kvm report

causes a SEGFAULT in the usual place:
(gdb) bt
0  0x0000000000470356 in machine__mmap_name (self=0x0, bf=0x7fffffffbdb0 " z\370\367\377\177", size=
    4096) at util/map.c:712
1  0x00000000004453e8 in perf_event__process_kernel_mmap (tool=0x7fffffffde10, event=0x7ffff7f87e38,
    machine=0x0) at util/event.c:550
2  0x00000000004458c9 in perf_event__process_mmap (tool=0x7fffffffde10, event=0x7ffff7f87e38, sample=
    0x7fffffffd2a0, machine=0x0) at util/event.c:656
3  0x00000000004733e0 in perf_session_deliver_event (session=0x91aca0, event=0x7ffff7f87e38, sample=
    0x7fffffffd2a0, tool=0x7fffffffde10, file_offset=7736) at util/session.c:979
...

The MMAP events in this case already contain the full path to the
module. No need to require it for the report path to.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1341241977-71535-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/map.c |   29 +++++++++++++++--------------
 1 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 35ae568..a1f4e36 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -669,25 +669,26 @@ struct machine *machines__find(struct rb_root *self, pid_t pid)
 struct machine *machines__findnew(struct rb_root *self, pid_t pid)
 {
 	char path[PATH_MAX];
-	const char *root_dir;
+	const char *root_dir = "";
 	struct machine *machine = machines__find(self, pid);
 
-	if (!machine || machine->pid != pid) {
-		if (pid == HOST_KERNEL_ID || pid == DEFAULT_GUEST_KERNEL_ID)
-			root_dir = "";
-		else {
-			if (!symbol_conf.guestmount)
-				goto out;
-			sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
-			if (access(path, R_OK)) {
-				pr_err("Can't access file %s\n", path);
-				goto out;
-			}
-			root_dir = path;
+	if (machine && (machine->pid == pid))
+		goto out;
+
+	if ((pid != HOST_KERNEL_ID) &&
+	    (pid != DEFAULT_GUEST_KERNEL_ID) &&
+	    (symbol_conf.guestmount)) {
+		sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
+		if (access(path, R_OK)) {
+			pr_err("Can't access file %s\n", path);
+			machine = NULL;
+			goto out;
 		}
-		machine = machines__add(self, pid, root_dir);
+		root_dir = path;
 	}
 
+	machine = machines__add(self, pid, root_dir);
+
 out:
 	return machine;
 }
-- 
1.7.1

Re: [GIT PULL 0/3] perf/urgent fixes

[Ingo Molnar]

* Arnaldo Carvalho de Melo <acme@infradead.org> wrote:

> Hi Ingo,
> 
> 	Please consider pulling,
> 
> - Arnaldo
> 
> The following changes since commit 662f5cedb38c4b88e1cebfd54a88159f2f7ab7b9:
> 
>   Merge branch 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent (2012-06-24 19:08:49 +0200)
> 
> are available in the git repository at:
> 
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux tags/perf-urgent-for-mingo
> 
> for you to fetch changes up to 7ed97ad41ffa94040dfd593948962a7e9e7b0db9:
> 
>   perf kvm: Fix segfault with report and mixed guestmount use (2012-07-02 14:03:50 -0300)
> 
> ----------------------------------------------------------------
> perf/urgent fixes:
> 
> . Fix creation of guest machine objects when build ids are disabled,
>   from David Ahern
> 
> . The kvm tool was trying to access an uninitialized guestmount variable, fix
>   from David Ahern.
> 
> . Restore perf script output to pre-libparseevent merge format, removing
>   duplicated info, fix from David Ahern
> 
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> ----------------------------------------------------------------
> David Ahern (3):
>       perf script: Fix format regression due to libtraceevent merge
>       perf kvm: Fix regression with guest machine creation
>       perf kvm: Fix segfault with report and mixed guestmount use
> 
>  tools/perf/util/map.c               |   29 +++++++++++++++--------------
>  tools/perf/util/session.c           |    2 +-
>  tools/perf/util/trace-event-parse.c |    3 +--
>  3 files changed, 17 insertions(+), 17 deletions(-)

Pulled, thanks Arnaldo!

	Ingo