Messages in this thread | | | Date | Tue, 6 Mar 2007 16:09:40 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: [ckrm-tech] [PATCH 0/2] resource control file system - aka containers on top of nsproxy! |
| |
On Mon, Mar 05, 2007 at 07:39:37PM +0100, Herbert Poetzl wrote: > > Thats why nsproxy has pointers to resource control objects, rather > > than embedding resource control information in nsproxy itself. > > which makes it a (name)space, no?
I tend to agree, yes!
> > This will let different nsproxy structures share the same resource > > control objects (ctlr_data) and thus be governed by the same > > parameters. > > as it is currently done for vfs, uts, ipc and soon > pid and network l2/l3, yes?
yes (by vfs do you mean mnt_ns?)
> > Where else do you think the resource control information for a > > container should be stored? > > an alternative for that is to keep the resource > stuff as part of a 'context' structure, and keep > a reference from the task to that (one less > indirection, as we had for vfs before)
something like:
struct resource_context { int cpu_limit; int rss_limit; /* all other limits here */ }
struct task_struct { ... struct resource_context *rc;
}
?
With this approach, it makes it hard to have task-grouping that are unique to each resource.
For ex: lets say that CPU and Memory needs to be divided as follows:
CPU : C1 (70%), C2 (30%) Mem : M1 (60%), M2 (40%)
Tasks T1, T2, T3, T4 are assigned to these resource classes as follows:
C1 : T1, T3 C2 : T2, T4 M1 : T1, T4 M2 : T2, T3
We had a lengthy discussion on this requirement here:
http://lkml.org/lkml/2006/11/6/95 http://lkml.org/lkml/2006/11/1/239
Linus also has expressed a similar view here:
http://lwn.net/Articles/94573/
Paul Menage's (and its clone rcfs) patches allows this flexibility by simply mounting different hierarchies:
mount -t container -o cpu none /dev/cpu mount -t container -o mem none /dev/mem
The task-groups created under /dev/cpu can be completely independent of task-groups created under /dev/mem.
Lumping together all resource parameters in one struct (like resource_context above) makes it difficult to provide this feature.
Now can we live w/o this flexibility? Maybe, I don't know for sure. Since (stability of) user-interface is in question, we need to take a carefull decision here.
> > then other derefences (->ctlr_data[] and ->limit) should be fast, as > > they should be in the cache? > > please provide real world numbers from testing ...
What kind of testing did you have in mind?
-- Regards, vatsa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |