Messages in this thread | | | Date | Fri, 12 Jan 2007 11:54:41 +0530 | From | Balbir Singh <> | Subject | Re: [ckrm-tech] [PATCH 4/6] containers: Simple CPU accounting container subsystem |
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Paul Menage wrote: > On 1/10/07, Balbir Singh <balbir@in.ibm.com> wrote: >> I have run into a problem running this patch on a powerpc box. Basically, >> the machine panics as soon as I mount the container filesystem with > > This is a multi-processor system?
Yes, it has 4 cpus
> > My guess is that it's a race in the subsystem API that I've been > meaning to deal with for some time - basically I've been using > (<foo>_subsys.subsys_id != -1) to indicate that <foo> is ready for > use, but there's a brief window during subsystem registration where > that's not actually true. > > I'll add an "active" field in the container_subsys structure, which > isn't set until registration is completed, and subsystems should use > that instead. container_register_subsys() will set it just prior to > releasing callback_mutex, and cpu_acct.c (and other subsystems) will > check <foo>_subsys.active rather than (<foo>_subsys.subsys_id != -1) >
I tried something similar, I added an activated field, which is set to true when the ->create() callback is invoked. That did not help either, the machine still panic'ed.
>> I am trying to figure out the reason for the panic and trying to find >> a fix. Since the introduction of whole hierarchy system, the debugging >> has gotten a bit harder and taking longer, hence I was wondering if you >> had any clues about the problem >> > > Yes, the multi-hierarchy support does make the whole code a little > more complex - but people presented reasonable scenarios where a > single container tree for all resource controllers just wasn't > flexible enough. >
I see the need for it, but I wonder if we should start with that right away. I understand that people might want to group cpusets differently from their grouping of let's say the cpu resource manager. I would still prefer to start with one hierarchy and then move to multiple hierarchies. I am concerned that adding complexity upfront might turn off people from using the infrastructure.
> Paul
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Balbir Singh, Linux Technology Center, IBM Software Labs - 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/
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