Re: [PATCH v6 00/37] Memory allocation profiling

Suren Baghdasaryan
2024-04-06T21:42:54Z

On Fri, Apr 5, 2024 at 8:38 AM Klara Modin <klarasmodin@gmail.com> wrote:
>
>
>
> On 2024-04-05 17:20, Suren Baghdasaryan wrote:
> > On Fri, Apr 5, 2024 at 7:30 AM Klara Modin <klarasmodin@gmail.com> wrote:
> >>
> >> On 2024-04-05 16:14, Suren Baghdasaryan wrote:
> >>> On Fri, Apr 5, 2024 at 6:37 AM Klara Modin <klarasmodin@gmail.com> wrote:
> >>>> If I enable this, I consistently get percpu allocation failures. I can
> >>>> occasionally reproduce it in qemu. I've attached the logs and my config,
> >>>> please let me know if there's anything else that could be relevant.
> >>>
> >>> Thanks for the report!
> >>> In debug_alloc_profiling.log I see:
> >>>
> >>> [ 7.445127] percpu: limit reached, disable warning
> >>>
> >>> That's probably the reason. I'll take a closer look at the cause of
> >>> that and how we can fix it.
> >>
> >> Thanks!
> >
> > In the build that produced debug_alloc_profiling.log I think we are
> > consuming all the per-cpu memory reserved for the modules. Could you
> > please try this change and see if that fixes the issue:
> >
> > include/linux/percpu.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/linux/percpu.h b/include/linux/percpu.h
> > index a790afba9386..03053de557cf 100644
> > --- a/include/linux/percpu.h
> > +++ b/include/linux/percpu.h
> > @@ -17,7 +17,7 @@
> > /* enough to cover all DEFINE_PER_CPUs in modules */
> > #ifdef CONFIG_MODULES
> > #ifdef CONFIG_MEM_ALLOC_PROFILING
> > -#define PERCPU_MODULE_RESERVE (8 << 12)
> > +#define PERCPU_MODULE_RESERVE (8 << 13)
> > #else
> > #define PERCPU_MODULE_RESERVE (8 << 10)
> > #endif
> >
>
> Yeah, that patch fixes the issue for me.
>
> Thanks,
> Tested-by: Klara Modin

Official fix is posted at
https://lore.kernel.org/all/20240406214044.1114406-1-surenb@google.com/
Thanks,
Suren.