Re: [PATCH v5 08/12] tests/plugin/bb: migrate to new per_vcpu API

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

On 3/1/24 2:26 PM, Alex Bennée wrote:
> Pierrick Bouvier <pierrick.bouvier@linaro.org> writes:
> 
>> On 2/29/24 6:21 PM, Alex Bennée wrote:
>>> Pierrick Bouvier <pierrick.bouvier@linaro.org> writes:
>>>
>>>> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
>>> I did notice there is a discrepancy between what libisns and libb
>>> report. The libb looks like an overcount so I wonder if there are some
>>> instructions we are not picking up but I can't see where that would be.
>>>     ➜  ./qemu-hppa -plugin ./tests/plugin/libinsn.so -plugin
>>> ./tests/plugin/libbb.so,inline=true -d plugin
>>> ./tests/tcg/hppa-linux-user/sha512
>>>     1..10
>>>     ok 1 - do_test(&tests[i])
>>>     ok 2 - do_test(&tests[i])
>>>     ok 3 - do_test(&tests[i])
>>>     ok 4 - do_test(&tests[i])
>>>     ok 5 - do_test(&tests[i])
>>>     ok 6 - do_test(&tests[i])
>>>     ok 7 - do_test(&tests[i])
>>>     ok 8 - do_test(&tests[i])
>>>     ok 9 - do_test(&tests[i])
>>>     ok 10 - do_test(&tests[i])
>>>     CPU0: bb's: 54282, insns: 775697
>>>     Total: bb's: 54282, insns: 775697
>>>     cpu 0 insns: 774827
>>>     total insns: 774827
>>> Although weirdly maybe only an hppa thing. Richard?
>>>
>>
>> Do you observe the exact same number if you run only one of the plugin?
>>
>> bb count number of instructions in an executed block, while insn
>> effectively count every instructions ran.
>> Maybe there is hppa specifity that makes some tb exit in the middle,
>> thus executing less instructions than expected from bb count.
> 
> Almost certainly - I just wasn't sure what would do that on straight
> line code. Probably some funky aspect of HPPA I'm not aware off ;-)
> 
>>
>> I don't know how to reproduce this test. Did you run it from a
>> specific docker env?
> 
> If you have docker enabled the "make check-tcg" will build and use a
> container to build the test cases. If you are on debian you just need:
> 
>      apt install gcc-hppa-linux-gnu libc6-dev-hppa-cross
> 
> and re-run configure.
> 

Thanks.

The difference observed predates this series, so there should definitely 
be something specific to this arch.

>>
>>>     ➜  ./qemu-aarch64 -plugin ./tests/plugin/libinsn.so -plugin ./tests/plugin/libbb.so,inline=true -d plugin  ./tests/tcg/aarch64-linux-user/sha512
>>>     1..10
>>>     ok 1 - do_test(&tests[i])
>>>     ok 2 - do_test(&tests[i])
>>>     ok 3 - do_test(&tests[i])
>>>     ok 4 - do_test(&tests[i])
>>>     ok 5 - do_test(&tests[i])
>>>     ok 6 - do_test(&tests[i])
>>>     ok 7 - do_test(&tests[i])
>>>     ok 8 - do_test(&tests[i])
>>>     ok 9 - do_test(&tests[i])
>>>     ok 10 - do_test(&tests[i])
>>>     CPU0: bb's: 41513, insns: 302671
>>>     Total: bb's: 41513, insns: 302671
>>>     cpu 0 insns: 302671
>>>     total insns: 302671
>>> Anyway:
>>> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
>>>
>