linux_dsm_epyc7002/arch/arm64
Jeremy Linton e156ab71a9 arm64: topology: Avoid checking numa mask for scheduler MC selection
The numa mask subset check can often lead to system hang or crash during
CPU hotplug and system suspend operation if NUMA is disabled. This is
mostly observed on HMP systems where the CPU compute capacities are
different and ends up in different scheduler domains. Since
cpumask_of_node is returned instead core_sibling, the scheduler is
confused with incorrect cpumasks(e.g. one CPU in two different sched
domains at the same time) on CPU hotplug.

Lets disable the NUMA siblings checks for the time being, as NUMA in
socket machines have LLC's that will assure that the scheduler topology
isn't "borken".

The NUMA check exists to assure that if a LLC within a socket crosses
NUMA nodes/chiplets the scheduler domains remain consistent. This code will
likely have to be re-enabled in the near future once the NUMA mask story
is sorted.  At the moment its not necessary because the NUMA in socket
machines LLC's are contained within the NUMA domains.

Further, as a defensive mechanism during hot-plug, lets assure that the
LLC siblings are also masked.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-06-07 17:42:11 +01:00
..
boot This pull request contains Broadcom ARM64-based SoCs Device Tree fixes 2018-04-27 10:21:18 +02:00
configs arm64: defconfig: add CONFIG_UNIPHIER_THERMAL and CONFIG_SNI_AVE 2018-03-27 15:31:19 +02:00
crypto kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers 2018-04-07 19:04:02 +09:00
include arm64: KVM: Move VCPU_WORKAROUND_2_FLAG macros to the top of the file 2018-06-02 10:42:54 +01:00
kernel arm64: topology: Avoid checking numa mask for scheduler MC selection 2018-06-07 17:42:11 +01:00
kvm arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_ID 2018-05-31 18:00:59 +01:00
lib arm64: avoid instrumenting atomic_ll_sc.o 2018-04-27 12:14:44 +01:00
mm arm64: Unify kernel fault reporting 2018-05-23 11:46:42 +01:00
net bpf, arm64: fix out of bounds access in tail call 2018-02-22 16:06:28 -08:00
xen arm64: mm: Add additional parameter to uaccess_ttbr0_disable 2018-01-17 13:57:49 +01:00
Kconfig arm64: Add ARCH_WORKAROUND_2 probing 2018-05-31 17:34:38 +01:00
Kconfig.debug
Kconfig.platforms arm64: add Renesas R8A77965 support 2018-03-13 19:05:58 +01:00
Makefile arm64: support __int128 with clang 2018-04-24 19:07:55 +01:00