diff options
| author | Sven Schnelle <svens@linux.ibm.com> | 2021-08-27 20:21:05 +0200 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2021-09-07 13:38:41 +0200 |
| commit | a052096bdd6809eeab809202726634d1ac975aa1 (patch) | |
| tree | 80e72fe5fe0a406816ca467958870dd0f8dc5bec /arch/s390/kernel/smp.c | |
| parent | 88b604263f3d6eedae0b1c2c3bbd602d1e2e8775 (diff) | |
s390/topology: fix topology information when calling cpu hotplug notifiers
The cpu hotplug notifiers are called without updating the core/thread
masks when a new CPU is added. This causes problems with code setting
up data structures in a cpu hotplug notifier, and relying on that later
in normal code.
This caused a crash in the new core scheduling code (SCHED_CORE),
where rq->core was set up in a notifier depending on cpu masks.
To fix this, add a cpu_setup_mask which is used in update_cpu_masks()
instead of the cpu_online_mask to determine whether the cpu masks should
be set for a certain cpu. Also move update_cpu_masks() to update the
masks before calling notify_cpu_starting() so that the notifiers are
seeing the updated masks.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Cc: <stable@vger.kernel.org>
[hca@linux.ibm.com: get rid of cpu_online_mask handling]
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/smp.c')
| -rw-r--r-- | arch/s390/kernel/smp.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 2a991e43ead3..1a04e5bdf655 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -95,6 +95,7 @@ __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS]; #endif static unsigned int smp_max_threads __initdata = -1U; +cpumask_t cpu_setup_mask; static int __init early_nosmt(char *s) { @@ -902,13 +903,14 @@ static void smp_start_secondary(void *cpuvoid) vtime_init(); vdso_getcpu_init(); pfault_init(); + cpumask_set_cpu(cpu, &cpu_setup_mask); + update_cpu_masks(); notify_cpu_starting(cpu); if (topology_cpu_dedicated(cpu)) set_cpu_flag(CIF_DEDICATED_CPU); else clear_cpu_flag(CIF_DEDICATED_CPU); set_cpu_online(cpu, true); - update_cpu_masks(); inc_irq_stat(CPU_RST); local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); @@ -950,10 +952,13 @@ early_param("possible_cpus", _setup_possible_cpus); int __cpu_disable(void) { unsigned long cregs[16]; + int cpu; /* Handle possible pending IPIs */ smp_handle_ext_call(); - set_cpu_online(smp_processor_id(), false); + cpu = smp_processor_id(); + set_cpu_online(cpu, false); + cpumask_clear_cpu(cpu, &cpu_setup_mask); update_cpu_masks(); /* Disable pseudo page faults on this cpu. */ pfault_fini(); |