Hi Sudeep,
On Tue, Jul 17, 2018 at 7:02 PM Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
> On Tue, Jul 17, 2018 at 04:55:22PM +0100, Sudeep Holla wrote:
> > Going through the code again, I think I understand the problem here.
> > We use the topology_core_mask pointers which are stashed in cpu_groups[]
> > But, the cpumask themselves will be getting modified as the cpus go up
> > and down, so we need to make a copy instead of just using the pointer.
> > I will see what we can do to fix that.
>
> This is what I could come up with. I haven't tested this but just compiled
> it. Let me know if this resolves the issue.
Thanks, it did!
> From: Sudeep Holla <sudeep.holla@xxxxxxx>
> Date: Tue, 17 Jul 2018 17:45:20 +0100
> Subject: [PATCH] drivers/firmware: psci_checker: stash and use topology_core_cpumask for hotplug tests
>
> Commit 7f9545aa1a91 ("arm64: smp: remove cpu and numa topology information
> when hotplugging out CPU") updates the cpu topology when the CPU is
> hotplugged out. However the PSCI checker code uses the topology_core_cpumask
> pointers for some of the cpu hotplug testing. Since the pointer to the
> core_cpumask of the first CPU in the group is used, which when that CPU
> itself is hotpugged out is just set to itself, the testing terminates
> after that particular CPU is tested out. But the intention of this tests
> is to cover all the CPU in the group.
>
> In order to support that, we need to stash the topology_core_cpumask
> before the start of the test and use that value instead of pointer to a
> cpumask which will be updated on CPU hotplug.
>
> Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Fixes: 7f9545aa1a91a9a4 ("arm64: smp: remove cpu and numa topology
information when hotplugging out CPU")
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
