| Message ID | 20210218195549.1696769-1-vipinsh@google.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | cgroup: New misc cgroup controller | expand |
Hello. On Thu, Feb 18, 2021 at 11:55:47AM -0800, Vipin Sharma <vipinsh@google.com> wrote: > This patch is creating a new misc cgroup controller for allocation and > tracking of resources which are not abstract like other cgroup > controllers. Please don't refer to this as "allocation" anywhere, that has a specific meaning (see Resource Distribution Models in Documentation/admin-gruide/cgroup-v2.rst). > This controller was initially proposed as encryption_id but after > the feedbacks, it is now changed to misc cgroup. > https://lore.kernel.org/lkml/20210108012846.4134815-2-vipinsh@google.com/ Interesting generalization. I wonder what else could fit under this as well. (It resembles pids controller on the cover.) > Please provide any feedback for this RFC or if it is good for > merging then I can send a patch for merging. A new controller is added exposed with v1 attributes. I'm not convinced it is desirable to change the frozen v1 controllers' API? (And therefore promote it as well.) Beware, bikeshedding. The name is very non-descriptive, potentially suggesting catch-all semantics. It'd deserve a further thought. My idea would be limit(s) or counter controller. My few cents here (and some more in reply to the patch), Michal
On Tue, Feb 23, 2021 at 07:24:33PM +0100, Michal Koutný wrote: > Hello. > > On Thu, Feb 18, 2021 at 11:55:47AM -0800, Vipin Sharma <vipinsh@google.com> wrote: > > This patch is creating a new misc cgroup controller for allocation and > > tracking of resources which are not abstract like other cgroup > > controllers. > Please don't refer to this as "allocation" anywhere, that has a specific > meaning (see Resource Distribution Models in > Documentation/admin-gruide/cgroup-v2.rst). Yeah, it should be "Limits". I will update the text. > > > This controller was initially proposed as encryption_id but after > > the feedbacks, it is now changed to misc cgroup. > > https://lore.kernel.org/lkml/20210108012846.4134815-2-vipinsh@google.com/ > Interesting generalization. I wonder what else could fit under this as > well. (It resembles pids controller on the cover.) > > > Please provide any feedback for this RFC or if it is good for > > merging then I can send a patch for merging. > A new controller is added exposed with v1 attributes. I'm not convinced > it is desirable to change the frozen v1 controllers' API? (And therefore > promote it as well.) This is a very trivial controller. I believe once it becomes public it can be helpful down the line to the v1 users, who cannot use v2 yet, for some simple resource accounting, like us, we have the need for ASIDs accounting in v1 until we move to v2. If the community has strong objection then I can remove v1 support. > > Beware, bikeshedding. The name is very non-descriptive, potentially > suggesting catch-all semantics. It'd deserve a further thought. My idea > would be limit(s) or counter controller. Limit and counter are kind of suggesting the underlying technique for accounting instead of a generic name to denote resource types managed by this controller. One can argue that if top level names are similar to Resource Destribution Model then may be it makes sense to combine resources with similar accounting technique under one controller. I am looking at misc as a controller which is for resources not having proper home in other controllers or not big enough to deserve their own controller. I agree with you coming up with a name which check all boxes of requirements won't be possible. We have discussed name sev cgroup, kvm cgroup, encryption_id cgroup before reaching to an agreement on misc cgroup. I am open to other names if they are better suited for this controller and makes more sense. Thanks Vipin
Hello, This patch is creating a new misc cgroup controller for allocation and tracking of resources which are not abstract like other cgroup controllers. This controller was initially proposed as encryption_id but after the feedbacks, it is now changed to misc cgroup. https://lore.kernel.org/lkml/20210108012846.4134815-2-vipinsh@google.com/ Changes from the encryption_id controller are: 1. There are only 3 files misc.{capacity, max, current} for all resources compared to each resource having their own 3 files in encryption_id cgroup. 2. If a resource capacity is 0 then it is considered inactive and won't show up in control files. 2. This is a lockless implementation similar to page counter APIs compared to single lock implementation in encryption_id cgroup. Please provide any feedback for this RFC or if it is good for merging then I can send a patch for merging. Thanks Vipin Sharma (2): cgroup: sev: Add misc cgroup controller cgroup: sev: Miscellaneous cgroup documentation. Documentation/admin-guide/cgroup-v1/misc.rst | 1 + Documentation/admin-guide/cgroup-v2.rst | 64 ++- arch/x86/kvm/svm/sev.c | 60 ++- arch/x86/kvm/svm/svm.h | 1 + include/linux/cgroup_subsys.h | 4 + include/linux/misc_cgroup.h | 75 +++ init/Kconfig | 14 + kernel/cgroup/Makefile | 1 + kernel/cgroup/misc.c | 456 +++++++++++++++++++ 9 files changed, 664 insertions(+), 12 deletions(-) create mode 100644 Documentation/admin-guide/cgroup-v1/misc.rst create mode 100644 include/linux/misc_cgroup.h create mode 100644 kernel/cgroup/misc.c