6.6-stable review patch. If anyone has any objections, please let me know.
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From: Helge Deller deller@gmx.de
commit 82b143aeb169b8b55798d7d2063032e1a6ceeeb0 upstream.
This reverts commit 0921244f6f4f0d05698b953fe632a99b38907226.
It broke CPU hotplugging because it modifies the __cpu_possible_mask after bootup, so that it will be different than nr_cpu_ids, which then effictively breaks the workqueue setup code and triggers crashes when shutting down CPUs at runtime.
Guenter was the first who noticed the wrong values in __cpu_possible_mask, since the cpumask Kunit tests were failig.
Reverting this commit fixes both issues, but sadly brings back this uncritical runtime warning: register_cpu_capacity_sysctl: too early to get CPU4 device!
Signed-off-by: Helge Deller deller@gmx.de Reported-by: Guenter Roeck linux@roeck-us.net Link: https://lkml.org/lkml/2024/2/4/146 Link: https://lore.kernel.org/lkml/Zb0mbHlIud_bqftx@slm.duckdns.org/t/ Cc: stable@vger.kernel.org # 6.0+ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/parisc/kernel/processor.c | 8 -------- 1 file changed, 8 deletions(-)
--- a/arch/parisc/kernel/processor.c +++ b/arch/parisc/kernel/processor.c @@ -172,7 +172,6 @@ static int __init processor_probe(struct p->cpu_num = cpu_info.cpu_num; p->cpu_loc = cpu_info.cpu_loc;
- set_cpu_possible(cpuid, true); store_cpu_topology(cpuid);
#ifdef CONFIG_SMP @@ -474,13 +473,6 @@ static struct parisc_driver cpu_driver _ */ void __init processor_init(void) { - unsigned int cpu; - reset_cpu_topology(); - - /* reset possible mask. We will mark those which are possible. */ - for_each_possible_cpu(cpu) - set_cpu_possible(cpu, false); - register_parisc_driver(&cpu_driver); }