Messages in this thread |  | | Subject | Re: [PATCH V3 1/5] perf/core: Add PERF_SAMPLE_WEIGHT_STRUCT | From | "Liang, Kan" <> | Date | Fri, 5 Feb 2021 08:45:59 -0500 |
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On 2/5/2021 5:43 AM, Namhyung Kim wrote: > On Fri, Feb 5, 2021 at 12:24 AM Liang, Kan <kan.liang@linux.intel.com> wrote: >> >> On 2/4/2021 9:00 AM, Namhyung Kim wrote: >>> Hi Kan, >>> >>> On Sat, Jan 30, 2021 at 2:25 AM Liang, Kan <kan.liang@linux.intel.com> wrote: >>> [SNIP] >>>> diff --git a/include/uapi/linux/perf_event.h >>>> b/include/uapi/linux/perf_event.h >>>> index b15e344..c50718a 100644 >>>> --- a/include/uapi/linux/perf_event.h >>>> +++ b/include/uapi/linux/perf_event.h >>>> @@ -145,12 +145,14 @@ enum perf_event_sample_format { >>>> PERF_SAMPLE_CGROUP = 1U << 21, >>>> PERF_SAMPLE_DATA_PAGE_SIZE = 1U << 22, >>>> PERF_SAMPLE_CODE_PAGE_SIZE = 1U << 23, >>>> + PERF_SAMPLE_WEIGHT_STRUCT = 1U << 24, >>>> >>>> - PERF_SAMPLE_MAX = 1U << 24, /* non-ABI */ >>>> + PERF_SAMPLE_MAX = 1U << 25, /* non-ABI */ >>>> >>>> __PERF_SAMPLE_CALLCHAIN_EARLY = 1ULL << 63, /* non-ABI; internal use */ >>>> }; >>>> >>>> +#define PERF_SAMPLE_WEIGHT_TYPE (PERF_SAMPLE_WEIGHT | >>>> PERF_SAMPLE_WEIGHT_STRUCT) >>> >>> I'm not sure you want to expose it in the uapi header as it's not >>> intended to be used IMHO. >>> >> >> I'm not sure I understood, but it's indeed used in the tool patch set. >> >> https://lore.kernel.org/lkml/1612296553-21962-6-git-send-email-kan.liang@linux.intel.com/ > > Well, it's not a big deal.. but I just worried if some users might do > > event.attr.sample_type = PERF_SAMPLE_WEIGHT_TYPE; >
Yes, it's possible. For this case, Kernel returns -EINVAL.
Actually, even without the macro, users may still set PERF_SAMPLE_WEIGHT | PERF_SAMPLE_WEIGHT_STRUCT manually. We cannot control what a user sets. I don't think it's a problem as long as the kernel can handle it properly.
Thanks, Kan
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