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

[Alex Bennée]

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.

>
>>    ➜  ./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>
>> 

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro