Re: [PATCH v9 6/7] cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst
From: Tejun Heo <tj@kernel.org>
Date: 2021-12-13 21:00:23
Also in:
linux-doc, linux-kselftest, lkml
From: Tejun Heo <tj@kernel.org>
Date: 2021-12-13 21:00:23
Also in:
linux-doc, linux-kselftest, lkml
Hello, On Sun, Dec 05, 2021 at 01:32:19PM -0500, Waiman Long wrote:
+ In the case of an invalid partition root, a descriptive string on + why the partition is invalid is included within parentheses. + + Almost all possible state transitions among "member", valid + and invalid partition roots are allowed except from "member" + to invalid partition root.
So, this part still bothers me for the following two reasons that I brought up earlier: * When a valid partition turns invalid, now we have a reliable way of discovering what exactly caused the transition. However, when a user now fails to turn a member into partition, all they get is -EINVAL and there's no way to discover why it failed and the failure conditions that -EINVAL represents aren't simple. * In an automated configuration scenarios, this operation mode may be difficult to make reliable and lead to sporadic failures which can be tricky to track down. The core problem is that whether a given operation succeeds or not may depend on external states (CPU on/offline) which may change asynchronously in a way that the configuring entity doesn't have any control over. It's true that both are existing problems with the current partition interface and given that this is a pretty spcialized feature, this can be okay. Michal, what are your thoughts? Thanks. -- tejun