From: Jesse Larrew Date: Wed, 24 Apr 2013 06:05:22 +0000 (+0000) Subject: powerpc/pseries: RE-enable Virtual Processor Home Node updating X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b7abef045fdacdb40eef7f22ebbb566d63f9f240;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git powerpc/pseries: RE-enable Virtual Processor Home Node updating The new PRRN firmware feature provides a more convenient and event-driven interface than VPHN for notifying Linux of changes to the NUMA affinity of platform resources. However, for practical reasons, it may not be feasible for some customers to update to the latest firmware. For these customers, the VPHN feature supported on previous firmware versions may still be the best option. The VPHN feature was previously disabled due to races with the load balancing code when accessing the NUMA cpu maps, but the new stop_machine() approach protects the NUMA cpu maps from these concurrent accesses. It should be safe to re-enable this feature now. Signed-off-by: Nathan Fontenot Signed-off-by: Benjamin Herrenschmidt --- diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index f298a7d4b2ce..908699fb61c9 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1572,9 +1572,8 @@ int start_topology_update(void) vphn_enabled = 0; rc = of_reconfig_notifier_register(&dt_update_nb); } - } else if (0 && firmware_has_feature(FW_FEATURE_VPHN) && + } else if (firmware_has_feature(FW_FEATURE_VPHN) && get_lppaca()->shared_proc) { - /* Disabled until races with load balancing are fixed */ if (!vphn_enabled) { prrn_enabled = 0; vphn_enabled = 1;