> On 11 Apr 2022, at 16:20, Luca Fancellu <luca.fance...@arm.com> wrote:
>
> Cpu0 must remain in cpupool0, otherwise some operations like moving cpus
> between cpupools, cpu hotplug, destroying cpupools, shutdown of the host,
> might not work in a sane way.
>
> Signed-off-by: Luca Fancellu <luca.fance...@arm.com>
> ---
> Changes in v7:
> - new patch
> ---
> xen/common/sched/cpupool.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/xen/common/sched/cpupool.c b/xen/common/sched/cpupool.c
> index 86a175f99cd5..0a93bcc631bf 100644
> --- a/xen/common/sched/cpupool.c
> +++ b/xen/common/sched/cpupool.c
> @@ -572,6 +572,7 @@ static long cf_check cpupool_unassign_cpu_helper(void
> *info)
> * possible failures:
> * - last cpu and still active domains in cpupool
> * - cpu just being unplugged
> + * - Attempt to remove boot cpu from cpupool0
> */
> static int cpupool_unassign_cpu(struct cpupool *c, unsigned int cpu)
> {
> @@ -582,7 +583,12 @@ static int cpupool_unassign_cpu(struct cpupool *c,
> unsigned int cpu)
> debugtrace_printk("cpupool_unassign_cpu(pool=%u,cpu=%d)\n",
> c->cpupool_id, cpu);
>
> - if ( !cpu_online(cpu) )
> + /*
> + * Cpu0 must remain in cpupool0, otherwise some operations like moving
> cpus
> + * between cpupools, cpu hotplug, destroying cpupools, shutdown of the
> host,
> + * might not work in a sane way.
> + */
> + if ( (!c->cpupool_id && !cpu) || !cpu_online(cpu) )
> return -EINVAL;
>
> master_cpu = sched_get_resource_cpu(cpu);
> --
> 2.17.1
>
Hi,
I’m going to address the comment on this serie before re-pushing it, I see there
are no comments on this patch, so I’m wondering, when you have time, if you
can give me some feedback on this one.
Cheers,
Luca
