Re: [PATCH v4 08/10] cxl: add an optional pid check to event parsing

[Dave Jiang <dave.jiang@intel.com>]

On 11/8/2022 4:48 PM, Verma, Vishal L wrote:
> On Tue, 2022-11-08 at 11:30 -0700, Dave Jiang wrote:
>> From: Alison Schofield <alison.schofield@intel.com>
>>
>> When parsing CXL events, callers may only be interested in events
>> that originate from the current process. Introduce an optional
>> argument to the event trace context: event_pid. When event_pid is
>> present, only include events with a matching pid in the returned
>> JSON list. It is not a failure to see other, non matching results.
>> Simply skip those.
>>
>> The initial use case for this is the listing of media errors,
>> where only the media-errors requested by this process are wanted.
>>
>> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>>   cxl/event_trace.c |    5 +++++
>>   cxl/event_trace.h |    1 +
>>   2 files changed, 6 insertions(+)
> 
> I might be missing something - but this patch is added at then end,
> without subsequently using the event_pid in cxl-monitor? So why not
> leave this to be part of the media errors patches?

Alison, you want to move this to your series?

> 
>>
>> diff --git a/cxl/event_trace.c b/cxl/event_trace.c
>> index 490c30e1dbfc..89c9c2db26a3 100644
>> --- a/cxl/event_trace.c
>> +++ b/cxl/event_trace.c
>> @@ -215,6 +215,11 @@ static int cxl_event_parse_cb(struct tep_event *event, struct tep_record *record
>>                          return 0;
>>          }
>>   
>> +       if (event_ctx->event_pid) {
>> +               if (event_ctx->event_pid != tep_data_pid(event->tep, record))
>> +                       return 0;
>> +       }
>> +
>>          if (event_ctx->parse_event)
>>                  return event_ctx->parse_event(event, record, &event_ctx->jlist_head);
>>   
>> diff --git a/cxl/event_trace.h b/cxl/event_trace.h
>> index 89e98cafb320..e72b4347175e 100644
>> --- a/cxl/event_trace.h
>> +++ b/cxl/event_trace.h
>> @@ -15,6 +15,7 @@ struct event_ctx {
>>          const char *system;
>>          struct list_head jlist_head;
>>          const char *event_name;                                 /* optional */
>> +       int event_pid;                                          /* optional */
>>          int (*parse_event)(struct tep_event *event, struct tep_record *record,
>>                             struct list_head *jlist_head);       /* optional */
>>   };
>>
>>
>