diff mbox series

[v2] powerpc/perf/hv-24x7: Dont create sysfs event files for dummy events

Message ID 20201218100100.1166111-1-kjain@linux.ibm.com (mailing list archive)
State Changes Requested
Headers show
Series [v2] powerpc/perf/hv-24x7: Dont create sysfs event files for dummy events | expand

Commit Message

Kajol Jain Dec. 18, 2020, 10:01 a.m. UTC 
hv_24x7 performance monitoring unit creates list of supported events
from the event catalog obtained via HCALL. hv_24x7 catalog could also
contain invalid or dummy events (with names like FREE_* or CPM_FREE_*
and RESERVED*). These events do not have any hardware counters
backing them. So patch adds a check to string compare the event names
to filter out them.

Result in power9 machine:

Before this patch:
.....
  hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
  hv_24x7/RESERVED_NEST1,chip=?/                     [Kernel PMU event]
  hv_24x7/RESERVED_NEST10,chip=?/                    [Kernel PMU event]
  hv_24x7/RESERVED_NEST11,chip=?/                    [Kernel PMU event]
  hv_24x7/RESERVED_NEST12,chip=?/                    [Kernel PMU event]
  hv_24x7/RESERVED_NEST13,chip=?/                    [Kernel PMU event]
......

Dmesg:
[    0.000362] printk: console [hvc0] enabled
[    0.815452] hv-24x7: read 1530 catalog entries, created 537 event attrs
(0 failures), 275 descs

After this patch:
......
  hv_24x7/PM_XLINK2_OUT_ODD_AVLBL_CYC,chip=?/        [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
  hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
  hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
  hv_24x7/TOD,chip=?/                                [Kernel PMU event]
......

Demsg:
[    0.000357] printk: console [hvc0] enabled
[    0.808592] hv-24x7: read 1530 catalog entries, created 509 event attrs
(0 failures), 275 descs

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
---
 arch/powerpc/perf/hv-24x7.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

---
Changelog
v1 -> v2
- Include "RESERVED*" as part of the invalid event check as
  suggested by Madhavan Srinivasan
- Add new helper function "ignore_event" to check invalid/dummy
  events as suggested by Michael Ellerman
- Remove pr_info to print each invalid event as suggested by
  Michael Ellerman
---

Comments

Madhavan Srinivasan Dec. 19, 2020, 10:50 a.m. UTC | #1 
On 12/18/20 3:31 PM, Kajol Jain wrote:
> hv_24x7 performance monitoring unit creates list of supported events
> from the event catalog obtained via HCALL. hv_24x7 catalog could also
> contain invalid or dummy events (with names like FREE_* or CPM_FREE_*
> and RESERVED*). These events do not have any hardware counters
> backing them. So patch adds a check to string compare the event names
> to filter out them.
>
> Result in power9 machine:
>
> Before this patch:
> .....
>    hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
>    hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
>    hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
>    hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
>    hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
>    hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
>    hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
>    hv_24x7/RESERVED_NEST1,chip=?/                     [Kernel PMU event]
>    hv_24x7/RESERVED_NEST10,chip=?/                    [Kernel PMU event]
>    hv_24x7/RESERVED_NEST11,chip=?/                    [Kernel PMU event]
>    hv_24x7/RESERVED_NEST12,chip=?/                    [Kernel PMU event]
>    hv_24x7/RESERVED_NEST13,chip=?/                    [Kernel PMU event]
> ......
>
> Dmesg:
> [    0.000362] printk: console [hvc0] enabled
> [    0.815452] hv-24x7: read 1530 catalog entries, created 537 event attrs
> (0 failures), 275 descs
>
> After this patch:
> ......
>    hv_24x7/PM_XLINK2_OUT_ODD_AVLBL_CYC,chip=?/        [Kernel PMU event]
>    hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
>    hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
>    hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
>    hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
>    hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
>    hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
>    hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
>    hv_24x7/TOD,chip=?/                                [Kernel PMU event]
> ......
>
> Demsg:
> [    0.000357] printk: console [hvc0] enabled
> [    0.808592] hv-24x7: read 1530 catalog entries, created 509 event attrs
> (0 failures), 275 descs

Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>


>
> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
> ---
>   arch/powerpc/perf/hv-24x7.c | 17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
>
> ---
> Changelog
> v1 -> v2
> - Include "RESERVED*" as part of the invalid event check as
>    suggested by Madhavan Srinivasan
> - Add new helper function "ignore_event" to check invalid/dummy
>    events as suggested by Michael Ellerman
> - Remove pr_info to print each invalid event as suggested by
>    Michael Ellerman
> ---
> diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
> index 6e7e820508df..1a6004d88f98 100644
> --- a/arch/powerpc/perf/hv-24x7.c
> +++ b/arch/powerpc/perf/hv-24x7.c
> @@ -764,6 +764,16 @@ static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
>   	return ev_len;
>   }
>
> +/*
> + * Return true incase of invalid or dummy events with names like FREE_* or CPM_FREE_*
> + * and RESERVED*
> + */
> +static bool ignore_event(const char *name)
> +{
> +	return (strstr(name, "FREE_") || !strncmp(name, "RESERVED", 8)) ?
> +			true : false;
> +}
> +
>   #define MAX_4K (SIZE_MAX / 4096)
>
>   static int create_events_from_catalog(struct attribute ***events_,
> @@ -894,6 +904,10 @@ static int create_events_from_catalog(struct attribute ***events_,
>
>   		name = event_name(event, &nl);
>
> +		if (ignore_event(name)) {
> +			junk_events++;
> +			continue;
> +		}
>   		if (event->event_group_record_len == 0) {
>   			pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
>   					event_idx, nl, name);
> @@ -955,6 +969,9 @@ static int create_events_from_catalog(struct attribute ***events_,
>   			continue;
>
>   		name  = event_name(event, &nl);
> +		if (ignore_event(name))
> +			continue;
> +
>   		nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
>   		ct    = event_data_to_attrs(event_idx, events + event_attr_ct,
>   					    event, nonce);
Michael Ellerman Dec. 21, 2020, 5:40 a.m. UTC | #2 
Kajol Jain <kjain@linux.ibm.com> writes:
> hv_24x7 performance monitoring unit creates list of supported events
> from the event catalog obtained via HCALL. hv_24x7 catalog could also
> contain invalid or dummy events (with names like FREE_* or CPM_FREE_*
> and RESERVED*). These events do not have any hardware counters
> backing them. So patch adds a check to string compare the event names
> to filter out them.
>
> Result in power9 machine:
>
> Before this patch:
> .....
>   hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
>   hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
>   hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
>   hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
>   hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
>   hv_24x7/RESERVED_NEST1,chip=?/                     [Kernel PMU event]
>   hv_24x7/RESERVED_NEST10,chip=?/                    [Kernel PMU event]
>   hv_24x7/RESERVED_NEST11,chip=?/                    [Kernel PMU event]
>   hv_24x7/RESERVED_NEST12,chip=?/                    [Kernel PMU event]
>   hv_24x7/RESERVED_NEST13,chip=?/                    [Kernel PMU event]
> ......
>
> Dmesg:
> [    0.000362] printk: console [hvc0] enabled
> [    0.815452] hv-24x7: read 1530 catalog entries, created 537 event attrs
> (0 failures), 275 descs
>
> After this patch:
> ......
>   hv_24x7/PM_XLINK2_OUT_ODD_AVLBL_CYC,chip=?/        [Kernel PMU event]
>   hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
>   hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
>   hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
>   hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
>   hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
>   hv_24x7/TOD,chip=?/                                [Kernel PMU event]
> ......
>
> Demsg:
> [    0.000357] printk: console [hvc0] enabled
> [    0.808592] hv-24x7: read 1530 catalog entries, created 509 event attrs
> (0 failures), 275 descs
>
> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
> ---
>  arch/powerpc/perf/hv-24x7.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> ---
> Changelog
> v1 -> v2
> - Include "RESERVED*" as part of the invalid event check as
>   suggested by Madhavan Srinivasan
> - Add new helper function "ignore_event" to check invalid/dummy
>   events as suggested by Michael Ellerman
> - Remove pr_info to print each invalid event as suggested by
>   Michael Ellerman
> ---
> diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
> index 6e7e820508df..1a6004d88f98 100644
> --- a/arch/powerpc/perf/hv-24x7.c
> +++ b/arch/powerpc/perf/hv-24x7.c
> @@ -764,6 +764,16 @@ static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
>  	return ev_len;
>  }
>  
> +/*
> + * Return true incase of invalid or dummy events with names like FREE_* or CPM_FREE_*
> + * and RESERVED*
> + */
> +static bool ignore_event(const char *name)
> +{
> +	return (strstr(name, "FREE_") || !strncmp(name, "RESERVED", 8)) ?
> +			true : false;

That's FREE_ anywhere in the string, which seems a bit loose.

Do we have any documentation or anything that tells us that any event
with "FREE_" in the name will always be invalid?

cheers
Kajol Jain Dec. 21, 2020, 9:02 a.m. UTC | #3 
On 12/21/20 11:10 AM, Michael Ellerman wrote:
> Kajol Jain <kjain@linux.ibm.com> writes:
>> hv_24x7 performance monitoring unit creates list of supported events
>> from the event catalog obtained via HCALL. hv_24x7 catalog could also
>> contain invalid or dummy events (with names like FREE_* or CPM_FREE_*
>> and RESERVED*). These events do not have any hardware counters
>> backing them. So patch adds a check to string compare the event names
>> to filter out them.
>>
>> Result in power9 machine:
>>
>> Before this patch:
>> .....
>>   hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
>>   hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
>>   hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
>>   hv_24x7/RESERVED_NEST1,chip=?/                     [Kernel PMU event]
>>   hv_24x7/RESERVED_NEST10,chip=?/                    [Kernel PMU event]
>>   hv_24x7/RESERVED_NEST11,chip=?/                    [Kernel PMU event]
>>   hv_24x7/RESERVED_NEST12,chip=?/                    [Kernel PMU event]
>>   hv_24x7/RESERVED_NEST13,chip=?/                    [Kernel PMU event]
>> ......
>>
>> Dmesg:
>> [    0.000362] printk: console [hvc0] enabled
>> [    0.815452] hv-24x7: read 1530 catalog entries, created 537 event attrs
>> (0 failures), 275 descs
>>
>> After this patch:
>> ......
>>   hv_24x7/PM_XLINK2_OUT_ODD_AVLBL_CYC,chip=?/        [Kernel PMU event]
>>   hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/              [Kernel PMU event]
>>   hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/       [Kernel PMU event]
>>   hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/       [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/         [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/    [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATSD_SENT,chip=?/                   [Kernel PMU event]
>>   hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/               [Kernel PMU event]
>>   hv_24x7/TOD,chip=?/                                [Kernel PMU event]
>> ......
>>
>> Demsg:
>> [    0.000357] printk: console [hvc0] enabled
>> [    0.808592] hv-24x7: read 1530 catalog entries, created 509 event attrs
>> (0 failures), 275 descs
>>
>> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
>> ---
>>  arch/powerpc/perf/hv-24x7.c | 17 +++++++++++++++++
>>  1 file changed, 17 insertions(+)
>>
>> ---
>> Changelog
>> v1 -> v2
>> - Include "RESERVED*" as part of the invalid event check as
>>   suggested by Madhavan Srinivasan
>> - Add new helper function "ignore_event" to check invalid/dummy
>>   events as suggested by Michael Ellerman
>> - Remove pr_info to print each invalid event as suggested by
>>   Michael Ellerman
>> ---
>> diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
>> index 6e7e820508df..1a6004d88f98 100644
>> --- a/arch/powerpc/perf/hv-24x7.c
>> +++ b/arch/powerpc/perf/hv-24x7.c
>> @@ -764,6 +764,16 @@ static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
>>  	return ev_len;
>>  }
>>  
>> +/*
>> + * Return true incase of invalid or dummy events with names like FREE_* or CPM_FREE_*
>> + * and RESERVED*
>> + */
>> +static bool ignore_event(const char *name)
>> +{
>> +	return (strstr(name, "FREE_") || !strncmp(name, "RESERVED", 8)) ?
>> +			true : false;
> 
> That's FREE_ anywhere in the string, which seems a bit loose.
> 
> Do we have any documentation or anything that tells us that any event
> with "FREE_" in the name will always be invalid?

Hi Michael,
      We don't have any such document which says any event with "FREE_"
in the name will be invalid. So I will replace strstr check with strcmp
to look for events with names have "FREE" or "CPM_FREE" at start.

Thanks,
Kajol Jain

> 
> cheers
>
diff mbox series

Patch

diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 6e7e820508df..1a6004d88f98 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -764,6 +764,16 @@  static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
 	return ev_len;
 }
 
+/*
+ * Return true incase of invalid or dummy events with names like FREE_* or CPM_FREE_*
+ * and RESERVED*
+ */
+static bool ignore_event(const char *name)
+{
+	return (strstr(name, "FREE_") || !strncmp(name, "RESERVED", 8)) ?
+			true : false;
+}
+
 #define MAX_4K (SIZE_MAX / 4096)
 
 static int create_events_from_catalog(struct attribute ***events_,
@@ -894,6 +904,10 @@  static int create_events_from_catalog(struct attribute ***events_,
 
 		name = event_name(event, &nl);
 
+		if (ignore_event(name)) {
+			junk_events++;
+			continue;
+		}
 		if (event->event_group_record_len == 0) {
 			pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
 					event_idx, nl, name);
@@ -955,6 +969,9 @@  static int create_events_from_catalog(struct attribute ***events_,
 			continue;
 
 		name  = event_name(event, &nl);
+		if (ignore_event(name))
+			continue;
+
 		nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
 		ct    = event_data_to_attrs(event_idx, events + event_attr_ct,
 					    event, nonce);