Messages in this thread | | | Date | Wed, 15 Dec 2021 13:55:05 -0500 | Subject | Re: [PATCH v9 6/7] cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst | From | Waiman Long <> |
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On 12/15/21 13:35, Tejun Heo wrote: > Hello, Waiman. > > On Wed, Dec 15, 2021 at 01:16:43PM -0500, Waiman Long wrote: >> Allowing direct transition from member to invalid partition doesn't feel >> right for me. A casual user may assume a partition is correctly formed >> without double checking the "cpuset.partition" value. Returning an error >> will prevent this kind of issue. If returning more information about the >> failure is the main reason for allowing the invalid partition transition, we >> can extend the "cpuset.partition" read syntax to also show the reason for >> the previous failure. > I don't think it's a good idea to display error messages without a way to > link the error to the one who triggered it. This is the same problem we had > with resettable counters. It only works for scenarios where one guy is > sitting in front of the computer but gets nastry for more complex scnearios > and automation. Yes, I agree it is not a good way to handle this issue. > > I understand that allowing transitions to invalid state can feel jarring. > There are pros and cons to both approaches. It's similar dynamics tho. > Erroring out may be more intuitive for a casual user but makes it harder for > more complex scenarios because whether a given operation errors or not is > dependent on external asynchronous states, there's no good way of reporting > the exact nature of the error or detecting when the operation would succeed > in the future, and the error conditions are rather arbitrary.
Thanks for the explanation. Yes, there are always pros and cons for different approach to a problem. I am not totally against allowing member to invalid partition transition. In that case, reading back "cpuset.partition" is a must to verify that it is really a success.
How about we allow transition to an invalid partition state but still return an error?
Regards, Longman
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