Re: [PATCH 3/3] x86/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH

[Anshuman Khandual <anshuman.khandual@arm.com>]

On 8/30/22 15:30, James Clark wrote:
> 
> 
> On 29/08/2022 07:55, Anshuman Khandual wrote:
>> Ensure all platform specific event flags are within PERF_EVENT_FLAG_ARCH.
>>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
>> Cc: Jiri Olsa <jolsa@kernel.org>
>> Cc: Namhyung Kim <namhyung@kernel.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Borislav Petkov <bp@alien8.de>
>> Cc: x86@kernel.org
>> Cc: linux-perf-users@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>  arch/x86/events/amd/core.c |  2 ++
>>  arch/x86/events/core.c     | 16 ++++++++++++++++
>>  2 files changed, 18 insertions(+)
>>
>> diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
>> index 9ac3718410ce..7aee514285ba 100644
>> --- a/arch/x86/events/amd/core.c
>> +++ b/arch/x86/events/amd/core.c
>> @@ -1469,6 +1469,8 @@ __init int amd_pmu_init(void)
>>  	else
>>  		memcpy(hw_cache_event_ids, amd_hw_cache_event_ids, sizeof(hw_cache_event_ids));
>>  
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PAIR);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AMD_BRS);
>>  	return 0;
>>  }
>>  
>> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
>> index f969410d0c90..98fe13f50632 100644
>> --- a/arch/x86/events/core.c
>> +++ b/arch/x86/events/core.c
>> @@ -2083,6 +2083,22 @@ static int __init init_hw_perf_events(void)
>>  
>>  	pr_info("Performance Events: ");
>>  
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LDLAT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_ST_HSW);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LD_HSW);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_NA_HSW);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_DYNAMIC);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_EXCL_ACCT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_AUTO_RELOAD);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LARGE_PEBS);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_VIA_PT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_LBR_SELECT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_TOPDOWN);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_STLAT);
>> +	BUILD_BUG_ON(~PERF_EVENT_FLAG_ARCH & PERF_X86_EVENT_PEBS_LAT_HYBRID);
>> +
> 
> Hi Anshuman,
> 
> You can use static_assert() and then put them in the global scope. If
> they're next to the definition of these it will be clearer and easier to
> maintain.

Right, will do the required change.

> 
> Also, I'm assuming that this now causes a build failure, so I would
> include the change to expand PERF_EVENT_FLAG_ARCH as the first commit in
> the set. That way we can see at least one proposed solution.

Sure, will expand PERF_EVENT_FLAG_ARCH into 0x000FFFFF.