kata-containers/s390-tools
1
0
Fork 0
mirror of https://github.com/ibm-s390-linux/s390-tools.git synced 2026-08-05 02:14:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

cpuplugd: Halt cpu hotplugging on vertical polarization

Browse Source 
On vertical polarization, kernel can be adjusting CPU capacities
dynamically, and cpuplugd can interfere this with hotplug operations
causing performance degradation. To prevent this, check if system has
switched its polarization state, and act accordingly.
If system is on vertical polarization when daemon starts, no CPU hotplug
action is triggered. If system changes to vertical polarization during
daemon runtime, revert cpuhotplug adjustments and stop further CPU
hotplug actions. If system switches back to horizontal polarization
during runtime of the daemon, start evaluating CPU hotplug rules and
trigger adjustments.

Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This commit is contained in:
Mete Durlu
2024-05-23 13:58:08 +02:00
committed by Jan Höppner
parent c91d172c99
commit 147ff1bf49
6 changed files with 111 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files
cpuplugd/man/cpuplugd.8
+3
View File
@@ -22,6 +22,9 @@ of active CPUs are reset to the values they had before the cpuplugd was started.
This program can be used to control the number of CPUs for Linux on z/VM
and for Linux in LPAR mode. The memory hotplug feature (CMM page pool) applies
to Linux on z/VM only.
The cpuplugd daemon stops any CPU hot-plug operations when the system switches
to vertical polarization, thus avoiding possible performance penalties.
.
.SH OPTIONS
.TP