Re: [PATCH v6 3/3] selftests/mm: add new selftests for KSM

[David Hildenbrand <david@redhat.com>]

On 13.04.23 15:07, David Hildenbrand wrote:
> On 12.04.23 05:16, Stefan Roesch wrote:
>> This adds three new tests to the selftests for KSM.  These tests use the
>> new prctl API's to enable and disable KSM.
>>
>> 1) add new prctl flags to prctl header file in tools dir
>>
>>      This adds the new prctl flags to the include file prct.h in the
>>      tools directory.  This makes sure they are available for testing.
>>
>> 2) add KSM prctl merge test
>>
>>      This adds the -t option to the ksm_tests program.  The -t flag
>>      allows to specify if it should use madvise or prctl ksm merging.
>>
>> 3) add KSM get merge type test
>>
>>      This adds the -G flag to the ksm_tests program to query the KSM
>>      status with prctl after KSM has been enabled with prctl.
>>
>> 4) add KSM fork test
>>
>>      Add fork test to verify that the MMF_VM_MERGE_ANY flag is inherited
>>      by the child process.
>>
>> 5) add two functions for debugging merge outcome
>>
>>      This adds two functions to report the metrics in /proc/self/ksm_stat
>>      and /sys/kernel/debug/mm/ksm.
>>
>> The debugging can be enabled with the following command line:
>> make -C tools/testing/selftests TARGETS="mm" --keep-going \
>>           EXTRA_CFLAGS=-DDEBUG=1
> 
> Would it make sense to instead have a "-D" (if still unused) runtime
> options to print this data? Dead code that's not compiled is a bit
> unfortunate as it can easily bit-rot.
> 
> 
> 
> This patch essentially does two things
> 
> 1) Add the option to run all tests/benchmarks with the PRCTL instead of
> MADVISE
> 
> 2) Add some functional KSM tests for the new PRCTL (fork, enabling
> works, disabling works).
> 
> The latter should rather go into ksm_functional_tests().


"tools/testing/selftests/mm/ksm_functional_tests.c" is what I wanted to say.

-- 
Thanks,

David / dhildenb