diff options
| author | Aaron Tomlin <atomlin@atomlin.com> | 2025-10-10 21:28:53 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-11-26 15:20:51 +0100 |
| commit | cd22926af45400093738c758b6749de8035ed5a8 (patch) | |
| tree | 12edfbf74edaf0886e7e14ffc39f6568a1c9aece /Documentation/ABI/testing/sysfs-devices-system-cpu | |
| parent | f10c23fa159c5481dfe0025e619dc5ef844f6ce1 (diff) | |
tick/nohz: Expose housekeeping CPUs in sysfs
Expose the current system-defined list of housekeeping CPUs in a new
sysfs file: /sys/devices/system/cpu/housekeeping.
This provides userspace performance tuning tools and resource managers
with a canonical, reliable method to accurately identify the cores
responsible for essential kernel maintenance workloads (RCU, timer
callbacks, and unbound workqueues). Currently, tooling must manually
calculate the housekeeping set by parsing complex kernel boot parameters
(like isolcpus= and nohz_full=) and system topology, which is prone to
error. This dedicated file simplifies the configuration of low-latency
workloads.
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Link: https://patch.msgid.link/20251011012853.7539-2-atomlin@atomlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-system-cpu')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 8aed6d94c4cd..3a05604c21bf 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -764,6 +764,17 @@ Description: participate in load balancing. These CPUs are set by boot parameter "isolcpus=". +What: /sys/devices/system/cpu/housekeeping +Date: Oct 2025 +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: + (RO) the list of logical CPUs that are designated by the kernel as + "housekeeping". Each CPU are responsible for handling essential + system-wide background tasks, including RCU callbacks, delayed + timer callbacks, and unbound workqueues, minimizing scheduling + jitter on low-latency, isolated CPUs. These CPUs are set when boot + parameter "isolcpus=nohz" or "nohz_full=" is specified. + What: /sys/devices/system/cpu/crash_hotplug Date: Aug 2023 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> |