Re: [PATCH] perf topdown: Don't require config1==0 for a slots event

["Chen, Zide" <zide.chen@intel.com>]

On 9/16/2026 3:44 PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Low] perf: missing explicit <stdio.h> and <string.h> inclusions
> --
> 
> commit 197eea3115a0d065dc53e6f96ad2fd38fdb9bc99
> Author: Zide Chen <zide.chen@intel.com>
> 
> perf topdown: Don't require config1==0 for a slots event
> 
> This commit modifies the topdown slots architecture check to no longer require
> config1 == 0, fixing an issue where explicit slots events were duplicated in
> scheduling. It also adds a new test to verify that an explicit metrics_clear
> slots event doesn't trigger extra injections.
> 
>> diff --git a/tools/perf/arch/x86/tests/topdown.c b/tools/perf/arch/x86/tests/topdown.c
>> index 2b6f47ce49324..b1ce9f83db00e 100644
>> --- a/tools/perf/arch/x86/tests/topdown.c
>> +++ b/tools/perf/arch/x86/tests/topdown.c
> [ ... ]
>> @@ -229,10 +229,38 @@ static int test__x86_topdown_slots_injection(struct test_suite *test __maybe_unu
>>  	return TEST_OK;
>>  }
>>  
>> +/*
>> + * An explicit "slots,metrics_clear=1" event is still the slots event and
>> + * must not cause an extra slots event to be injected into the group.
>> + */
>> +static int test__x86_topdown_metrics_clear(struct test_suite *test __maybe_unused,
>> +					   int subtest __maybe_unused)
>> +{
>> +	struct perf_pmu *pmu;
>> +	char event_str[128];
>> +	int ret;
>> +
>> +	if (!topdown_sys_has_perf_metrics())
>> +		return TEST_OK;
>> +
>> +	pmu = perf_pmus__find_by_type(PERF_TYPE_RAW);
>> +	if (!pmu || !perf_pmu__has_format(pmu, "metrics_clear"))
>> +		return TEST_OK;
>> +
>> +	snprintf(event_str, sizeof(event_str),
>> +		 "{%s/slots,metrics_clear=1/,%s/topdown-retiring/}",
>> +		 pmu->name, pmu->name);
> 
> [Severity: Low]
> Does this new function test__x86_topdown_metrics_clear() need explicit header
> inclusions for musl compatibility?
> 
> This code relies on an implicit declaration of <stdio.h> for snprintf().
> Missing POSIX headers can cause build failures when compiling the perf tool
> with strict libc implementations like musl instead of glibc.
> 
> Should <stdio.h> (and potentially <string.h>) be explicitly included at the top
> of this file to prevent musl compilation failures?

Not needed. tools/perf/util/pmu.h, along with debug.h (which is also
included), explicitly pulls in <stdio.h>.

Additionally, this file already contains other calls to snprintf(). If
the required header dependency were missing, those existing uses would
already fail to build.