Re: [PATCH] tests/plugin: Remove duplicate insn log from libinsn.so

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> On 6/12/23 04:50, Richard Henderson wrote:
>> On 6/11/23 02:14, Alex Bennée wrote:
>>>
>>> Richard Henderson <richard.henderson@linaro.org> writes:
>>>
>>>> This is a perfectly natural occurrence for x86 "rep movb",
>>>> where the "rep" prefix forms a counted loop of the one insn.
>>>>
>>>> During the tests/tcg/multiarch/memory test, this logging is
>>>> triggered over 350000 times.  Within the context of cross-i386-tci
>>>> build, which is already slow by nature, the logging is sufficient
>>>> to push the test into timeout.
>>>
>>> How does this get triggered because I added these:
>>>
>>> # non-inline runs will trigger the duplicate instruction heuristics in 
>>> libinsn.so
>>> run-plugin-%-with-libinsn.so:
>>>     $(call run-test, $@, \
>>>       $(QEMU) -monitor none -display none \
>>>           -chardev file$(COMMA)path=$@.out$(COMMA)id=output \
>>>                    -plugin ../../plugin/libinsn.so$(COMMA)inline=on \
>>>               -d plugin -D $*-with-libinsn.so.pout \
>>>           $(QEMU_OPTS) $*)
>>>
>>> to prevent the callback versions from being called for x86. The original
>>> intent of the check was to detect failures due to cpu_io_recompile, see
>>> e025d799af (tests/plugin: expand insn test to detect duplicate instructions)
>> I have no idea how, but it's happening.
>> 
>>>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>>>> ---
>>>> Irritatingly, it doesn't timeout locally, so I used staging to 
>>>> double-check:
>>>>
>>>> Fail: https://gitlab.com/qemu-project/qemu/-/jobs/4450754282#L5062
>>>> Pass: https://gitlab.com/qemu-project/qemu/-/jobs/4450927108
>> Note that in the pass case, we don't even log that the test ran.
>
> Any further thoughts on this?  Otherwise I'll merge it to get rid of
> the cross-i386-tci failure...
>
>
> r~

I'm happy to drop the feature from the plugin but the clean-up also
needs to be applied to the run-plugin-%-with-libinsn.so: rules for i386
and x86_64.

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro