Hi Sudeep,

On Fri, Jul 15, 2022 at 12:28 PM Sudeep Holla [off-list ref] wrote:

init_cpu_topology() is called only once at the boot and all the cache
attributes are detected early for all the possible CPUs. However when
the CPUs are hotplugged out, the cacheinfo gets removed. While the
attributes are added back when the CPUs are hotplugged back in as part
of CPU hotplug state machine, it ends up called quite late after the
update_siblings_masks() are called in the secondary_start_kernel()
resulting in wrong llc_sibling_masks.

Move the call to detect_cache_attributes() inside update_siblings_masks()
to ensure the cacheinfo is updated before the LLC sibling masks are
updated. This will fix the incorrect LLC sibling masks generated when
the CPUs are hotplugged out and hotplugged back in again.

Reported-by: Ionela Voinescu <redacted>
Tested-by: Ionela Voinescu <redacted>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Ionela Voinescu <redacted>
Signed-off-by: Sudeep Holla <redacted>
---
 drivers/base/arch_topology.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

v1->v2:
        - No change in this patch, but 1/2 was added to fix possible
          bug "sleeping in the atomic context" with this patch.
        - Added all the received tags

Thank you, the "Early cacheinfo failed, ret = -12" is gone.

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

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