Messages in this thread | | | Date | Fri, 9 Sep 2022 10:55:55 +0800 | Subject | Re: [External] Re: [PATCH] cgroup/cpuset: Add a new isolated mems.policy type. | From | Zhongkun He <> |
| |
> On Wed 07-09-22 21:50:24, Zhongkun He wrote: > [...] >>> Do you really need to change the policy itself or only the effective >>> nodemask? Do you need any other policy than bind and preferred? >> >> Yes, we need to change the policy, not only his nodemask. we really want >> policy is interleave, and extend it to weight-interleave. >> Say something like the following >> node weight >> interleave: 0-3 1:1:1:1 default one by one >> weight-interleave: 0-3 1:2:4:6 alloc pages by weight >> (User set weight.) >> In the actual usecase, the remaining resources of each node are different, >> and the use of interleave cannot maximize the use of resources. > > OK, this seems a separate topic. It would be good to start by proposing > that new policy in isolation with the semantic description. > >> Back to the previous question. >>> The question is how to implement that with a sensible semantic. >> >> Thanks for your analysis and suggestions.It is really difficult to add >> policy directly to cgroup for the hierarchical enforcement. It would be a >> good idea to add pidfd_set_mempolicy. > > Are you going to pursue that path? > >> Also, there is a new idea. >> We can try to separate the elements of mempolicy and use them independently. >> Mempolicy has two meanings: >> nodes:which nodes to use(nodes,0-3), we can use cpuset's effective_mems >> directly. >> mode:how to use them(bind,prefer,etc). change the mode to a >> cpuset->flags,such as CS_INTERLEAVE。 >> task_struct->mems_allowed is equal to cpuset->effective_mems,which is >> hierarchical enforcement。CS_INTERLEAVE can also be updated into tasks, >> just like other flags(CS_SPREAD_PAGE). >> When a process needs to allocate memory, it can find the appropriate node to >> allocate pages according to the flag and mems_allowed. > > I am not sure I see the advantage as the mode and nodes are always > closely coupled. You cannot really have one wihtout the other. >
Hi Michal, thanks for your suggestion and reply.
> Are you going to pursue that path?
Yes,I'll give it a try as it makes sense to modify the policy dynamically.
Thanks.
| |