Add debug verbose output to show how evsels were reordered by
parse_events__sort_events_and_fix_groups. For example:
```
$ perf record -v -e '{instructions,cycles}' true
Using CPUID GenuineIntel-6-B7-1
WARNING: events were regrouped to match PMUs
evlist after sorting/fixing: '{cpu_atom/instructions/,cpu_atom/cycles/},{cpu_core/instructions/,cpu_core/cycles/}'
```
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/parse-events.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 5152fd5a6ead..0f8fd5bee3a7 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -28,6 +28,7 @@
#include "util/evsel_config.h"
#include "util/event.h"
#include "util/bpf-filter.h"
+#include "util/stat.h"
#include "util/util.h"
#include "tracepoint.h"
@@ -2196,14 +2197,23 @@ int __parse_events(struct evlist *evlist, const char *str, const char *pmu_filte
if (ret2 < 0)
return ret;
- if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus)
- pr_warning("WARNING: events were regrouped to match PMUs\n");
-
/*
* Add list to the evlist even with errors to allow callers to clean up.
*/
evlist__splice_list_tail(evlist, &parse_state.list);
+ if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus) {
+ pr_warning("WARNING: events were regrouped to match PMUs\n");
+
+ if (verbose > 0) {
+ struct strbuf sb = STRBUF_INIT;
+
+ evlist__uniquify_name(evlist);
+ evlist__format_evsels(evlist, &sb, 1024);
+ pr_debug("evlist after sorting/fixing: '%s'\n", sb.buf);
+ strbuf_release(&sb);
+ }
+ }
if (!ret) {
struct evsel *last;
--
2.49.0.504.g3bcea36a83-goog
On 2025-04-02 12:47 p.m., Ian Rogers wrote:
> Add debug verbose output to show how evsels were reordered by
> parse_events__sort_events_and_fix_groups. For example:
> ```
> $ perf record -v -e '{instructions,cycles}' true
> Using CPUID GenuineIntel-6-B7-1
> WARNING: events were regrouped to match PMUs
> evlist after sorting/fixing: '{cpu_atom/instructions/,cpu_atom/cycles/},{cpu_core/instructions/,cpu_core/cycles/}'
> ```
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/util/parse-events.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 5152fd5a6ead..0f8fd5bee3a7 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -28,6 +28,7 @@
> #include "util/evsel_config.h"
> #include "util/event.h"
> #include "util/bpf-filter.h"
> +#include "util/stat.h"
> #include "util/util.h"
> #include "tracepoint.h"
>
> @@ -2196,14 +2197,23 @@ int __parse_events(struct evlist *evlist, const char *str, const char *pmu_filte
> if (ret2 < 0)
> return ret;
>
> - if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus)
> - pr_warning("WARNING: events were regrouped to match PMUs\n");
> -
> /*
> * Add list to the evlist even with errors to allow callers to clean up.
> */
> evlist__splice_list_tail(evlist, &parse_state.list);
>
> + if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus) {
> + pr_warning("WARNING: events were regrouped to match PMUs\n");
> +
> + if (verbose > 0) {
> + struct strbuf sb = STRBUF_INIT;
> +
> + evlist__uniquify_name(evlist);
> + evlist__format_evsels(evlist, &sb, 1024);
Why is the size even less than the one in pr_err?
The user probably prefer to get the complete list in the debug.
Thanks,
Kan> + pr_debug("evlist after sorting/fixing: '%s'\n", sb.buf);
> + strbuf_release(&sb);
> + }
> + }
> if (!ret) {
> struct evsel *last;
>
On Wed, Apr 2, 2025 at 10:52 AM Liang, Kan <kan.liang@linux.intel.com> wrote:
>
>
>
> On 2025-04-02 12:47 p.m., Ian Rogers wrote:
> > Add debug verbose output to show how evsels were reordered by
> > parse_events__sort_events_and_fix_groups. For example:
> > ```
> > $ perf record -v -e '{instructions,cycles}' true
> > Using CPUID GenuineIntel-6-B7-1
> > WARNING: events were regrouped to match PMUs
> > evlist after sorting/fixing: '{cpu_atom/instructions/,cpu_atom/cycles/},{cpu_core/instructions/,cpu_core/cycles/}'
> > ```
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> > tools/perf/util/parse-events.c | 16 +++++++++++++---
> > 1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index 5152fd5a6ead..0f8fd5bee3a7 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -28,6 +28,7 @@
> > #include "util/evsel_config.h"
> > #include "util/event.h"
> > #include "util/bpf-filter.h"
> > +#include "util/stat.h"
> > #include "util/util.h"
> > #include "tracepoint.h"
> >
> > @@ -2196,14 +2197,23 @@ int __parse_events(struct evlist *evlist, const char *str, const char *pmu_filte
> > if (ret2 < 0)
> > return ret;
> >
> > - if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus)
> > - pr_warning("WARNING: events were regrouped to match PMUs\n");
> > -
> > /*
> > * Add list to the evlist even with errors to allow callers to clean up.
> > */
> > evlist__splice_list_tail(evlist, &parse_state.list);
> >
> > + if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus) {
> > + pr_warning("WARNING: events were regrouped to match PMUs\n");
> > +
> > + if (verbose > 0) {
> > + struct strbuf sb = STRBUF_INIT;
> > +
> > + evlist__uniquify_name(evlist);
> > + evlist__format_evsels(evlist, &sb, 1024);
>
> Why is the size even less than the one in pr_err?
>
> The user probably prefer to get the complete list in the debug.
I thought the previous 2048 excessive but kept it for the previous
case to not change anything. If you are happier with 2048 here I don't
particularly mind, it is a lot to display in verbose output.
Thanks,
Ian
> Thanks,
> Kan> + pr_debug("evlist after sorting/fixing: '%s'\n", sb.buf);
> > + strbuf_release(&sb);
> > + }
> > + }
> > if (!ret) {
> > struct evsel *last;
> >
>
On 2025-04-02 2:15 p.m., Ian Rogers wrote:
> On Wed, Apr 2, 2025 at 10:52 AM Liang, Kan <kan.liang@linux.intel.com> wrote:
>>
>>
>>
>> On 2025-04-02 12:47 p.m., Ian Rogers wrote:
>>> Add debug verbose output to show how evsels were reordered by
>>> parse_events__sort_events_and_fix_groups. For example:
>>> ```
>>> $ perf record -v -e '{instructions,cycles}' true
>>> Using CPUID GenuineIntel-6-B7-1
>>> WARNING: events were regrouped to match PMUs
>>> evlist after sorting/fixing: '{cpu_atom/instructions/,cpu_atom/cycles/},{cpu_core/instructions/,cpu_core/cycles/}'
>>> ```
>>>
>>> Signed-off-by: Ian Rogers <irogers@google.com>
>>> ---
>>> tools/perf/util/parse-events.c | 16 +++++++++++++---
>>> 1 file changed, 13 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
>>> index 5152fd5a6ead..0f8fd5bee3a7 100644
>>> --- a/tools/perf/util/parse-events.c
>>> +++ b/tools/perf/util/parse-events.c
>>> @@ -28,6 +28,7 @@
>>> #include "util/evsel_config.h"
>>> #include "util/event.h"
>>> #include "util/bpf-filter.h"
>>> +#include "util/stat.h"
>>> #include "util/util.h"
>>> #include "tracepoint.h"
>>>
>>> @@ -2196,14 +2197,23 @@ int __parse_events(struct evlist *evlist, const char *str, const char *pmu_filte
>>> if (ret2 < 0)
>>> return ret;
>>>
>>> - if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus)
>>> - pr_warning("WARNING: events were regrouped to match PMUs\n");
>>> -
>>> /*
>>> * Add list to the evlist even with errors to allow callers to clean up.
>>> */
>>> evlist__splice_list_tail(evlist, &parse_state.list);
>>>
>>> + if (ret2 && warn_if_reordered && !parse_state.wild_card_pmus) {
>>> + pr_warning("WARNING: events were regrouped to match PMUs\n");
>>> +
>>> + if (verbose > 0) {
>>> + struct strbuf sb = STRBUF_INIT;
>>> +
>>> + evlist__uniquify_name(evlist);
>>> + evlist__format_evsels(evlist, &sb, 1024);
>>
>> Why is the size even less than the one in pr_err?
>>
>> The user probably prefer to get the complete list in the debug.
>
> I thought the previous 2048 excessive but kept it for the previous
> case to not change anything. If you are happier with 2048 here I don't
> particularly mind, it is a lot to display in verbose output.
Yes, I think the verbose output wouldn't bother the normal user. We only
use it when there is a problem. So detailed information should be
preferred.
Thanks,
Kan>
> Thanks,
> Ian
>
>> Thanks,
>> Kan> + pr_debug("evlist after sorting/fixing: '%s'\n", sb.buf);
>>> + strbuf_release(&sb);
>>> + }
>>> + }
>>> if (!ret) {
>>> struct evsel *last;
>>>
>>
>
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