From fa73b929e06521b176ab6a569e5b3d408440956f Mon Sep 17 00:00:00 2001 From: Jordan Christiansen Date: Sat, 24 Oct 2020 21:34:37 -0500 Subject: Add more details about how CPU limits work Signed-off-by: Jordan Christiansen --- docs/source/markdown/podman-build.1.md | 14 ++++++++------ docs/source/markdown/podman-create.1.md | 18 +++++++++++------- docs/source/markdown/podman-run.1.md | 16 +++++++++++----- 3 files changed, 30 insertions(+), 18 deletions(-) (limited to 'docs/source/markdown') diff --git a/docs/source/markdown/podman-build.1.md b/docs/source/markdown/podman-build.1.md index 821324f84..d05070fe1 100644 --- a/docs/source/markdown/podman-build.1.md +++ b/docs/source/markdown/podman-build.1.md @@ -111,17 +111,19 @@ network namespaces can be found. **--cpu-period**=*limit* -Limit the CPU CFS (Completely Fair Scheduler) period - -Limit the container's CPU usage. This flag tell the kernel to restrict the container's CPU usage to the period you specify. +Set the CPU period for the Completely Fair Scheduler (CFS), which is a +duration in microseconds. Once the container's CPU quota is used up, it will +not be scheduled to run until the current period ends. Defaults to 100000 +microseconds. **--cpu-quota**=*limit* -Limit the CPU CFS (Completely Fair Scheduler) quota +Limit the CPU Completely Fair Scheduler (CFS) quota. Limit the container's CPU usage. By default, containers run with the full -CPU resource. This flag tell the kernel to restrict the container's CPU usage -to the quota you specify. +CPU resource. The limit is a number in microseconds. If you provide a number, +the container will be allowed to use that much CPU time until the CPU period +ends (controllable via **--cpu-period**). **--cpu-shares**, **-c**=*shares* diff --git a/docs/source/markdown/podman-create.1.md b/docs/source/markdown/podman-create.1.md index 1f229a3a0..176f0ab3a 100644 --- a/docs/source/markdown/podman-create.1.md +++ b/docs/source/markdown/podman-create.1.md @@ -103,17 +103,19 @@ Write the pid of the `conmon` process to a file. `conmon` runs in a separate pro **--cpu-period**=*limit* -Limit the CPU CFS (Completely Fair Scheduler) period - -Limit the container's CPU usage. This flag tell the kernel to restrict the container's CPU usage to the period you specify. +Set the CPU period for the Completely Fair Scheduler (CFS), which is a +duration in microseconds. Once the container's CPU quota is used up, it will +not be scheduled to run until the current period ends. Defaults to 100000 +microseconds. **--cpu-quota**=*limit* -Limit the CPU CFS (Completely Fair Scheduler) quota +Limit the CPU Completely Fair Scheduler (CFS) quota. Limit the container's CPU usage. By default, containers run with the full -CPU resource. This flag tell the kernel to restrict the container's CPU usage -to the quota you specify. +CPU resource. The limit is a number in microseconds. If you provide a number, +the container will be allowed to use that much CPU time until the CPU period +ends (controllable via **--cpu-period**). **--cpu-rt-period**=*microseconds* @@ -169,7 +171,9 @@ PID container CPU CPU share **--cpus**=*number* -Number of CPUs. The default is *0.0* which means no limit. +Number of CPUs. The default is *0.0* which means no limit. This is shorthand +for **--cpu-period** and **--cpu-quota**, so you may only set either +**--cpus** or **--cpu-period** and **--cpu-quota**. **--cpuset-cpus**=*cpus* diff --git a/docs/source/markdown/podman-run.1.md b/docs/source/markdown/podman-run.1.md index b86c9b363..6df9b0351 100644 --- a/docs/source/markdown/podman-run.1.md +++ b/docs/source/markdown/podman-run.1.md @@ -118,15 +118,19 @@ Write the pid of the **conmon** process to a file. As **conmon** runs in a separ **--cpu-period**=*limit* -Limit the container's CPU usage by setting CPU CFS (Completely Fair Scheduler) period. +Set the CPU period for the Completely Fair Scheduler (CFS), which is a +duration in microseconds. Once the container's CPU quota is used up, it will +not be scheduled to run until the current period ends. Defaults to 100000 +microseconds. **--cpu-quota**=*limit* -Limit the CPU CFS (Completely Fair Scheduler) quota. +Limit the CPU Completely Fair Scheduler (CFS) quota. Limit the container's CPU usage. By default, containers run with the full -CPU resource. This flag tell the kernel to restrict the container's CPU usage -to the quota you specify. +CPU resource. The limit is a number in microseconds. If you provide a number, +the container will be allowed to use that much CPU time until the CPU period +ends (controllable via **--cpu-period**). **--cpu-rt-period**=*microseconds* @@ -180,7 +184,9 @@ division of CPU shares: **--cpus**=*number* -Number of CPUs. The default is *0.0* which means no limit. +Number of CPUs. The default is *0.0* which means no limit. This is shorthand +for **--cpu-period** and **--cpu-quota**, so you may only set either +**--cpus** or **--cpu-period** and **--cpu-quota**. **--cpuset-cpus**=*number* -- cgit v1.2.3-54-g00ecf