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

[Pierrick Bouvier]

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.

I don't know how to reproduce this test. Did you run it from a specific 
docker env?

>    ➜  ./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>