Ian Campbell 0a02d14545 Correct CPU usage calculation in presence of offline CPUs and newer Linux ...

In https://github.com/torvalds/linux/commit/5ca3726 (released in v4.7-rc1) the
content of the `cpuacct.usage_percpu` file in sysfs was changed to include both
online and offline cpus. This broke the arithmetic in the stats helpers used by
`docker stats`, since it was using the length of the PerCPUUsage array as a
proxy for the number of online CPUs.

Add current number of online CPUs to types.StatsJSON and use it in the
calculation.

Keep a fallback to `len(v.CPUStats.CPUUsage.PercpuUsage)` so this code
continues to work when talking to an older daemon. An old client talking to a
new daemon will ignore the new field and behave as before.

Fixes #28941.

Signed-off-by: Ian Campbell <ian.campbell@docker.com>
Upstream-commit: 54a5077ca5
Component: cli

2017-03-10 10:24:33 +00:00

components/cli

Correct CPU usage calculation in presence of offline CPUs and newer Linux

2017-03-10 10:24:33 +00:00

S

Description

The Docker CLI

clidocker

381 MiB

Languages

Go 92.3%

Shell 5.4%

Dockerfile 1.1%

Go-Checksums 0.7%

Makefile 0.3%

Other 0.2%