Re: [tip: perf/core] uprobes: switch to RCU Tasks Trace flavor for better performance

[Andrii Nakryiko]

On Tue, Sep 10, 2024 at 3:37 AM Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
>
> * Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote:
>
> > On Thu, Sep 5, 2024 at 8:03 AM tip-bot2 for Andrii Nakryiko
> > <tip-bot2@xxxxxxxxxxxxx> wrote:
> > >
> > > The following commit has been merged into the perf/core branch of tip:
> > >
> > > Commit-ID:     c4d4569c41f9cda745cfd1d8089ea3d3526bafe5
> > > Gitweb:        https://git.kernel.org/tip/c4d4569c41f9cda745cfd1d8089ea3d3526bafe5
> > > Author:        Andrii Nakryiko <andrii@xxxxxxxxxx>
> > > AuthorDate:    Tue, 03 Sep 2024 10:46:03 -07:00
> > > Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > > CommitterDate: Thu, 05 Sep 2024 16:56:15 +02:00
> > >
> >
> > Hm... This commit landed in perf/core, but is gone now (the rest of
> > patches is still there). Any idea what happened?
>
> Yeah, I'm getting this build failure:
>
>      kernel/events/uprobes.c:1158:9: error: implicit declaration of function ‘synchronize_rcu_tasks_trace’; did you mean ‘synchronize_rcu_tasks’? [-Werror=implicit-function-declaration]
>
> on x86-64 defconfig, when applied to today's perf/core.
>

I see, I need to add `select TASKS_TRACE_RCU` to UPROBES kconfig, I'll
fix it up and send this patch separately.

Next time please let me know ASAP about issues with my patches so I
can fix stuff like this quickly.

> Thanks,
>
>         Ingo