Subject: Re: [PATCH] perf pmu: Fix event list for uncore PMUs
To:     Jiri Olsa <jolsa@redhat.com>
CC:     <peterz@infradead.org>, <mingo@redhat.com>, <acme@kernel.org>,
        <mark.rutland@arm.com>, <alexander.shishkin@linux.intel.com>,
        <namhyung@kernel.org>, <irogers@google.com>,
        <kan.liang@linux.intel.com>, <linux-perf-users@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <1639670017-74918-1-git-send-email-john.garry@huawei.com>
 <YcGJJ2g+i5qWea7d@krava>
From:   John Garry <john.garry@huawei.com>
Message-ID: <bbf9c0b4-c048-3adf-5282-2355aa648acf@huawei.com>
Date:   Tue, 21 Dec 2021 09:10:37 +0000
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On 21/12/2021 07:58, Jiri Olsa wrote:
>> +	/* Different names -> never duplicates */
>> +	if (strcmp(alias_a->name, alias_b->name))
>> +		return false;
>> +	if (!alias_a->pmu)
>> +		return true;
>> +	if (!alias_b->pmu)
>> +		return true;
> nit could be:
> 
> 	if (!alias_a->pmu || !alias_b->pmu)
> 		return true;
> 
> would be great to have more comments explaining the check
> 

This is just a sanity check that both strings are non-NULL as we do a 
strcmp() next. So would this be better:

if (!alias_a->pmu || !alias_b->pmu || !strcmp(alias_a->pmu, alias_b->pmu))
	return true

?

It will spill a line.

Thanks,
John

> thanks,
> jirka
> 
>> +	if (!strcmp(alias_a->pmu, alias_b->pmu))
>> +		return true;
>> +	/* uncore PMUs */