Em Tue, Sep 10, 2013 at 10:17:28AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Sep 10, 2013 at 03:05:03PM +0200, Stephane Eranian escreveu:
> > On Tue, Sep 10, 2013 at 3:00 PM, Arnaldo Carvalho de Melo
> > <a...@ghostprotocols.net> wrote:
> > > Em Mon, Sep 09, 2013 at 04:48:44PM -0300, Arnaldo Carvalho de Melo
> > > escreveu:
> > > +++ b/kernel/events/core.c
> > > @@ -5039,6 +5039,7 @@ static void perf_event_mmap_output(struct
> > > perf_event *event,
> > > mmap_event->event_id.header.size +=
> > > sizeof(mmap_event->maj);
> > > mmap_event->event_id.header.size +=
> > > sizeof(mmap_event->min);
> > > mmap_event->event_id.header.size +=
> > > sizeof(mmap_event->ino);
> > > + mmap_event->event_id.header.size +=
> > > sizeof(mmap_event->ino_generation);
> > > }
> > > perf_event_header__init_id(&mmap_event->event_id.header, &sample,
> > > event);
> > Arg, yes, this is missing.
> > Do you want to submit the patch?
> I will, in some jiffies, just rebooting with the patched kernel to
> re-run tperf test.
> > Thanks for tracking it down.
> np :-)
More fallout, this time the resulting tools fail to run on older
kernels, i.e. any kernel that doesn't have perf_event_attr.mmap2,
doesn't matter the event type:
[acme@zoo linux]$ perf record usleep 1
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event
(cycles).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
usleep: Terminated
[acme@zoo linux]$ perf record -e cpu-clock usleep 1
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event
(cpu-clock).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
usleep: Terminated
[acme@zoo linux]$
That is because kernel/events/core.c perf_copy_attr() has this test:
if (attr->__reserved_1)
return -EINVAL;
So we must have the handling we have for other things that were added
in the past, like .sample_id_all, .exclude_guest, etc, like is done in
the attached patch, please ack.
Ingo, since you haven't merged my latest perf/urgent pull req, do you
want me to fold this into the patch that makes the tooling side use
PERF_RECORD_MMAP2?
- Arnaldo
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ff2098b..404599d 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -27,6 +27,7 @@
static struct {
bool sample_id_all;
bool exclude_guest;
+ bool mmap2;
} perf_missing_features;
#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
@@ -677,7 +678,7 @@ void perf_evsel__config(struct perf_evsel *evsel,
attr->sample_type |= PERF_SAMPLE_WEIGHT;
attr->mmap = track;
- attr->mmap2 = track;
+ attr->mmap2 = track && !perf_missing_features.mmap2;
attr->comm = track;
/*
@@ -1017,6 +1018,8 @@ static int __perf_evsel__open(struct perf_evsel *evsel,
struct cpu_map *cpus,
}
fallback_missing_features:
+ if (perf_missing_features.mmap2)
+ evsel->attr.mmap2 = 0;
if (perf_missing_features.exclude_guest)
evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
retry_sample_id:
@@ -1081,8 +1084,11 @@ try_fallback:
if (err != -EINVAL || cpu > 0 || thread > 0)
goto out_close;
- if (!perf_missing_features.exclude_guest &&
- (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
+ if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
+ perf_missing_features.mmap2 = true;
+ goto fallback_missing_features;
+ } else if (!perf_missing_features.exclude_guest &&
+ (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
perf_missing_features.exclude_guest = true;
goto fallback_missing_features;
} else if (!perf_missing_features.sample_id_all) {
