[Devel] [PATCH RHEL9 COMMIT] configs: Disable automatic NUMA balancing by default

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-362.18.1.vz9.40.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-362.18.1.vz9.40.5
------>
commit 0e74f8997d7d911575667053d71986f444b389f6
Author: Konstantin Khorenko <khorenko at virtuozzo.com>
Date:   Thu Apr 18 21:31:40 2024 +0300

    configs: Disable automatic NUMA balancing by default
    
    In the scope of handling sporadic soft lockups inside big VMs on a VHC
    node (TTASK-65390) we have found that automatic kernel NUMA balancing
    triggers the problem.
    
    Previously we has already faced problems with kernel NUMA balancing on vz7
    https://virtuozzo.atlassian.net/browse/PSBM-49131
    and disabled it by default in kernel.
    
    But when rebasing onto RHEL8 we have checked the performance
    (https://virtuozzo.atlassian.net/browse/PSBM-126727) and found
    that having automatic kernel NUMA balancing enabled helps us a bit, thus
    we have enabled it back (enabled == RHEL8/9 default setting).
    
    Now, on vz9 (RHEL9-based kernel) we have faced the problem with sporadic
    soft lockups triggered by that automatic kernel NUMA balancing.
    
    We checked once again how automatic kernel NUMA balancing influences on
    the performance and found that the results are close, so until we
    investigate why memory migration between NUMA nodes takes that enormous
    amount of time (in the scope of
    https://virtuozzo.atlassian.net/browse/PSBM-156157), let's disable
    automatic kernel NUMA balancing by default in vz9 kernel.
    
    https://virtuozzo.atlassian.net/browse/PSBM-156155
    https://pmc.acronis.work/browse/TTASK-65390
    
    Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
    
    Feature: mm: performance enhancements
---
 .../custom-overrides/generic/CONFIG_NUMA_BALANCING_DEFAULT_ENABLED       | 1 +
 1 file changed, 1 insertion(+)

diff --git a/redhat/configs/custom-overrides/generic/CONFIG_NUMA_BALANCING_DEFAULT_ENABLED b/redhat/configs/custom-overrides/generic/CONFIG_NUMA_BALANCING_DEFAULT_ENABLED
new file mode 100644
index 000000000000..ef4532ae5fda
--- /dev/null
+++ b/redhat/configs/custom-overrides/generic/CONFIG_NUMA_BALANCING_DEFAULT_ENABLED
@@ -0,0 +1 @@
+CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=n