Re: [PATCH v7 00/17] mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8

[Amit Pundir <amit.pundir@linaro.org>]

On Fri, 7 Jul 2023 at 06:12, Isaac Manjarres <isaacmanjarres@google.com> wrote:
>
> On Wed, Jul 05, 2023 at 07:10:02PM +0530, Amit Pundir wrote:
> > Hi Catalin,
> >
> > On Wed, 5 Jul 2023 at 18:17, Catalin Marinas <catalin.marinas@arm.com> wrote:
> > >
> > > Hi,
> > >
> > > That's v7 of the series reducing the kmalloc() minimum alignment on
> > > arm64 to 8 (from 128). There's no new/different functionality, mostly
> > > cosmetic changes and acks/tested-bys.
> > >
> > > Andrew, if there are no further comments or objections to this version,
> > > are you ok to take the series through the mm tree? The arm64 changes are
> > > fairly small. Alternatively, I can push it into linux-next now to give
> > > it some wider exposure and decide whether to upstream it when the
> > > merging window opens. Thanks.
> >
> > This patch series broke Dragonboard 845c (SDM845) running AOSP.
> > With this series I run into random oops at __kmem_cache_alloc_node().
> > Here is one such boot log https://bugs.linaro.org/attachment.cgi?id=1146
>
> Hey Amit,
>
> From the log that you linked, this looks like there's corruption within
> the kmalloc slab caches. Can you please try enabling slub debug? That
> might give us more information about who is causing the corruption
> you're seeing here.
>
> To enable slub debug, you can add the following to your kernel config:
>
> CONFIG_SLUB_DEBUG=y
>
> and CONFIG_SLUB_DEBUG_ON=y or add slub_debug to the kernel command line.

Hi Issac, I can't reproduce this crash if I have slub_debug enabled
https://bugs.linaro.org/attachment.cgi?id=1149.

But I can still reproduce the crash, with the same build, if I just
remove the slub_debug bootarg
https://bugs.linaro.org/attachment.cgi?id=1150

Is there any specific (slub_debug=) option(s) you want me to try?
May be I can reproduce this bug just with those options.

Regards,
Amit Pundir

>
> --Isaac