Add more details about how CPU limits work

Signed-off-by: Jordan Christiansen <xordspar0@gmail.com>

3 files changed, 30 insertions, 18 deletions

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*