linux-kernel - Re: [PATCH] perf test: Fix skipping branch stack sampling test

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Message-Id: <F79AE69A-4D87-4F4E-A3FD-EF06A6E12839@linux.vnet.ibm.com>
Date:   Wed, 2 Nov 2022 12:21:11 +0530
From:   Athira Rajeev <atrajeev@...ux.vnet.ibm.com>
To:     James Clark <james.clark@....com>
Cc:     LKML <linux-kernel@...r.kernel.org>, Anshuman.Khandual@....com,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Kajol Jain <kjain@...ux.ibm.com>,
        linux-perf-users@...r.kernel.org, acme@...nel.org
Subject: Re: [PATCH] perf test: Fix skipping branch stack sampling test



> On 28-Oct-2022, at 5:52 PM, James Clark <james.clark@....com> wrote:
> 
> 
> 
> On 28/10/2022 13:19, James Clark wrote:
>> Commit f4a2aade6809 ("perf tests powerpc: Fix branch stack sampling test
>> to include sanity check for branch filter") added a skip if certain
>> branch options aren't available. But the change added both -b
>> (--branch-any) and --branch-filter options at the same time, which will
>> always result in a failure on any platform because the arguments can't
>> be used together.
>> 
>> Fix this by removing -b (--branch-any) and leaving --branch-filter which
>> already specifies 'any'. Also add warning messages to the test and perf
>> tool.
>> 
> 
> Hi Athira,
> 
> Are you able to check if this still skips for you on PowerPC with this
> new change?
> 

Hi James,

Sorry for the late response. I was out on vacation couple of days.

I tested with the new change and verified it skips on powerpc.

Tested-by: Athira Rajeev <atrajeev@...ux.vnet.ibm.com>

Thanks
Athira
> Thanks
> James
> 
>> Output on x86 before this fix:
>> 
>>   $ sudo ./perf test branch
>>   108: Check branch stack sampling         : Skip
>> 
>> After:
>> 
>>   $ sudo ./perf test branch
>>   108: Check branch stack sampling         : Ok
>> 
>> Fixes: f4a2aade6809 ("perf tests powerpc: Fix branch stack sampling test to include sanity check for branch filter")
>> Signed-off-by: James Clark <james.clark@....com>
>> ---
>> tools/perf/tests/shell/test_brstack.sh | 5 ++++-
>> tools/perf/util/parse-branch-options.c | 4 +++-
>> 2 files changed, 7 insertions(+), 2 deletions(-)
>> 
>> diff --git a/tools/perf/tests/shell/test_brstack.sh b/tools/perf/tests/shell/test_brstack.sh
>> index ec801cffae6b..d7ff5c4b4da4 100755
>> --- a/tools/perf/tests/shell/test_brstack.sh
>> +++ b/tools/perf/tests/shell/test_brstack.sh
>> @@ -13,7 +13,10 @@ fi
>> 
>> # skip the test if the hardware doesn't support branch stack sampling
>> # and if the architecture doesn't support filter types: any,save_type,u
>> -perf record -b -o- -B --branch-filter any,save_type,u true > /dev/null 2>&1 || exit 2
>> +if ! perf record -o- --no-buildid --branch-filter any,save_type,u -- true > /dev/null 2>&1 ; then
>> +	echo "skip: system doesn't support filter types: any,save_type,u"
>> +	exit 2
>> +fi
>> 
>> TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX)
>> 
>> diff --git a/tools/perf/util/parse-branch-options.c b/tools/perf/util/parse-branch-options.c
>> index 00588b9db474..31faf2bb49ff 100644
>> --- a/tools/perf/util/parse-branch-options.c
>> +++ b/tools/perf/util/parse-branch-options.c
>> @@ -102,8 +102,10 @@ parse_branch_stack(const struct option *opt, const char *str, int unset)
>> 	/*
>> 	 * cannot set it twice, -b + --branch-filter for instance
>> 	 */
>> -	if (*mode)
>> +	if (*mode) {
>> +		pr_err("Error: Can't use --branch-any (-b) with --branch-filter (-j).\n");
>> 		return -1;
>> +	}
>> 
>> 	return parse_branch_str(str, mode);
>> }