Re: [PATCH] perf evsel: Fix incorrect precise_ip in default event name

[zhangmengting]

Hi Namhyung,

Yeah, you are right. I'll send a new patch later.

Thanks,

Mengting Zhang


On 2017/11/10 14:30, Namhyung Kim wrote:

Hello,

On Fri, Nov 10, 2017 at 01:49:06PM +0800, Mengting Zhang wrote:

When no event is specified with -e option, perf will specify a
"cycles" event with the highest level of precision available in
perf_event_attr.precise_ip as the default event. But the evsel name
shows an incorrect precise ip, fix it.

For example, with a highest precision perf_event_attr.precise_ip = 2,
the evsel name "cycles:ppp" shows a wrong precision available.

Before:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (21 samples) ]
$./perf evlist -v
cycles:ppp: size: 112, { sample_period, sample_freq }: 4000,
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

After:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (16 samples) ]
$./perf evlist -v
cycles:pp: size: 112, { sample_period, sample_freq }: 4000,
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

Signed-off-by: Mengting Zhang 
---
  tools/perf/util/evsel.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0dccdb8..94cf11d 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -312,7 +312,7 @@ struct perf_evsel *perf_evsel__new_cycles(bool precise)
if (asprintf(>name, "cycles%s%s%.*s",
 (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
 attr.exclude_kernel ? "u" : "",
-attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
+attr.precise_ip ? attr.precise_ip : 0, "ppp") < 0)

I think you don't need to check value of the precise_ip anymore.
The following should be ok:

 attr.precise_ip, "ppp") < 0)

Thanks,
Namhyung


.

Re: [PATCH] perf evsel: Fix incorrect precise_ip in default event name

[zhangmengting]

Hi Namhyung,

Yeah, you are right. I'll send a new patch later.

Thanks,

Mengting Zhang


On 2017/11/10 14:30, Namhyung Kim wrote:

Hello,

On Fri, Nov 10, 2017 at 01:49:06PM +0800, Mengting Zhang wrote:

When no event is specified with -e option, perf will specify a
"cycles" event with the highest level of precision available in
perf_event_attr.precise_ip as the default event. But the evsel name
shows an incorrect precise ip, fix it.

For example, with a highest precision perf_event_attr.precise_ip = 2,
the evsel name "cycles:ppp" shows a wrong precision available.

Before:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (21 samples) ]
$./perf evlist -v
cycles:ppp: size: 112, { sample_period, sample_freq }: 4000,
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

After:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (16 samples) ]
$./perf evlist -v
cycles:pp: size: 112, { sample_period, sample_freq }: 4000,
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

Signed-off-by: Mengting Zhang 
---
  tools/perf/util/evsel.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0dccdb8..94cf11d 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -312,7 +312,7 @@ struct perf_evsel *perf_evsel__new_cycles(bool precise)
if (asprintf(>name, "cycles%s%s%.*s",
 (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
 attr.exclude_kernel ? "u" : "",
-attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
+attr.precise_ip ? attr.precise_ip : 0, "ppp") < 0)

I think you don't need to check value of the precise_ip anymore.
The following should be ok:

 attr.precise_ip, "ppp") < 0)

Thanks,
Namhyung


.

Re: [PATCH] perf evsel: Fix incorrect precise_ip in default event name

[Namhyung Kim]

Hello,

On Fri, Nov 10, 2017 at 01:49:06PM +0800, Mengting Zhang wrote:
> When no event is specified with -e option, perf will specify a
> "cycles" event with the highest level of precision available in
> perf_event_attr.precise_ip as the default event. But the evsel name
> shows an incorrect precise ip, fix it.
> 
> For example, with a highest precision perf_event_attr.precise_ip = 2,
> the evsel name "cycles:ppp" shows a wrong precision available.
> 
> Before:
> $./perf record sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.014 MB perf.data (21 samples) ]
> $./perf evlist -v
> cycles:ppp: size: 112, { sample_period, sample_freq }: 4000, 
> sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
> comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
> sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
> 
> After:
> $./perf record sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.014 MB perf.data (16 samples) ]
> $./perf evlist -v
> cycles:pp: size: 112, { sample_period, sample_freq }: 4000,
> sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
> comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
> sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
> 
> Signed-off-by: Mengting Zhang 
> ---
>  tools/perf/util/evsel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 0dccdb8..94cf11d 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -312,7 +312,7 @@ struct perf_evsel *perf_evsel__new_cycles(bool precise)
>   if (asprintf(>name, "cycles%s%s%.*s",
>(attr.precise_ip || attr.exclude_kernel) ? ":" : "",
>attr.exclude_kernel ? "u" : "",
> -  attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
> +  attr.precise_ip ? attr.precise_ip : 0, "ppp") < 0)

I think you don't need to check value of the precise_ip anymore.
The following should be ok:

 attr.precise_ip, "ppp") < 0)

Thanks,
Namhyung

Re: [PATCH] perf evsel: Fix incorrect precise_ip in default event name

[Namhyung Kim]

Hello,

On Fri, Nov 10, 2017 at 01:49:06PM +0800, Mengting Zhang wrote:
> When no event is specified with -e option, perf will specify a
> "cycles" event with the highest level of precision available in
> perf_event_attr.precise_ip as the default event. But the evsel name
> shows an incorrect precise ip, fix it.
> 
> For example, with a highest precision perf_event_attr.precise_ip = 2,
> the evsel name "cycles:ppp" shows a wrong precision available.
> 
> Before:
> $./perf record sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.014 MB perf.data (21 samples) ]
> $./perf evlist -v
> cycles:ppp: size: 112, { sample_period, sample_freq }: 4000, 
> sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
> comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
> sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
> 
> After:
> $./perf record sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.014 MB perf.data (16 samples) ]
> $./perf evlist -v
> cycles:pp: size: 112, { sample_period, sample_freq }: 4000,
> sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
> comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
> sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
> 
> Signed-off-by: Mengting Zhang 
> ---
>  tools/perf/util/evsel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 0dccdb8..94cf11d 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -312,7 +312,7 @@ struct perf_evsel *perf_evsel__new_cycles(bool precise)
>   if (asprintf(>name, "cycles%s%s%.*s",
>(attr.precise_ip || attr.exclude_kernel) ? ":" : "",
>attr.exclude_kernel ? "u" : "",
> -  attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
> +  attr.precise_ip ? attr.precise_ip : 0, "ppp") < 0)

I think you don't need to check value of the precise_ip anymore.
The following should be ok:

 attr.precise_ip, "ppp") < 0)

Thanks,
Namhyung

[PATCH] perf evsel: Fix incorrect precise_ip in default event name

[Mengting Zhang]

When no event is specified with -e option, perf will specify a
"cycles" event with the highest level of precision available in
perf_event_attr.precise_ip as the default event. But the evsel name
shows an incorrect precise ip, fix it.

For example, with a highest precision perf_event_attr.precise_ip = 2,
the evsel name "cycles:ppp" shows a wrong precision available.

Before:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (21 samples) ]
$./perf evlist -v
cycles:ppp: size: 112, { sample_period, sample_freq }: 4000, 
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

After:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (16 samples) ]
$./perf evlist -v
cycles:pp: size: 112, { sample_period, sample_freq }: 4000,
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

Signed-off-by: Mengting Zhang 
---
 tools/perf/util/evsel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0dccdb8..94cf11d 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -312,7 +312,7 @@ struct perf_evsel *perf_evsel__new_cycles(bool precise)
if (asprintf(>name, "cycles%s%s%.*s",
 (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
 attr.exclude_kernel ? "u" : "",
-attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
+attr.precise_ip ? attr.precise_ip : 0, "ppp") < 0)
goto error_free;
 out:
return evsel;
-- 
1.7.12.4

[PATCH] perf evsel: Fix incorrect precise_ip in default event name

[Mengting Zhang]

When no event is specified with -e option, perf will specify a
"cycles" event with the highest level of precision available in
perf_event_attr.precise_ip as the default event. But the evsel name
shows an incorrect precise ip, fix it.

For example, with a highest precision perf_event_attr.precise_ip = 2,
the evsel name "cycles:ppp" shows a wrong precision available.

Before:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (21 samples) ]
$./perf evlist -v
cycles:ppp: size: 112, { sample_period, sample_freq }: 4000, 
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

After:
$./perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (16 samples) ]
$./perf evlist -v
cycles:pp: size: 112, { sample_period, sample_freq }: 4000,
sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1,
comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2,
sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1

Signed-off-by: Mengting Zhang 
---
 tools/perf/util/evsel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0dccdb8..94cf11d 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -312,7 +312,7 @@ struct perf_evsel *perf_evsel__new_cycles(bool precise)
if (asprintf(>name, "cycles%s%s%.*s",
 (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
 attr.exclude_kernel ? "u" : "",
-attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
+attr.precise_ip ? attr.precise_ip : 0, "ppp") < 0)
goto error_free;
 out:
return evsel;
-- 
1.7.12.4