On 2015/3/19 7:40, Rik van Riel wrote:

On 03/18/2015 12:47 PM, Tejun Heo wrote:

quoted

On Mon, Mar 09, 2015 at 12:12:09PM -0400, riel@redhat.com wrote:

quoted

From: Rik van Riel <redacted>

The previous patch makes it so the code skips over isolcpus when
building scheduler load balancing domains. This makes it hard to
see for a user which of the CPUs in a cpuset are participating in
load balancing, and which ones are isolated cpus.

Add a cpuset.isolcpus file with info on which cpus in a cpuset are
isolated CPUs.

This file is read-only for now. In the future we could extend things
so isolcpus can be changed at run time, for the root (system wide)
cpuset only.

Didn't Li say that this is trivially computable from userland?  I'm
not sure this knob actually belongs to cpuset.

I don't know whether the information to compute this is
always visible from userland.  I am happy to drop this
patch if Li prefers things that way, though.

What I proposed is adding /sys/devices/system/cpu/isolated. Sysfs is
visible in containers, unless specially configured not so.