Re: Perf: WARNING: arch/x86/entry/common.c:624 idtentry_exit_cond_rcu+0x92/0xc0

[Naresh Kamboju]

On Thu, 2 Jul 2020 at 20:33, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

>
> How's this?
>
> DEFINE_IDTENTRY_DEBUG() is DEFINE_IDTENTRY_RAW on x86_64
>                            DEFINE_IDTENTRY on i386
>
> calling exc_debug_*() from DEFINE_IDTENTRY() does a double layer of
> idtentry_{enter,exit}*() functions.
>
> Also, handle_debug() is still a trainwreck, we should never get to
> cond_local_irq_enable() when !user.
>
> Completely untested...

Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Tested-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>

The patch did not apply smooth.
I have manually edited the patch [1] and applied it on top of linus
master branch
and tested on x86_64 and i386 and test pass and the reported WARNING gone.

ref:
patch link
[1] https://pastebin.com/mBHkP1A6

Test jobs links,
https://lkft.validation.linaro.org/scheduler/job/1538367#L1218
https://lkft.validation.linaro.org/scheduler/job/1538368#L1271

- Naresh