Messages in this thread | | | From | Rusty Russell <> | Subject | Re: module changes | Date | Wed, 19 Feb 2003 09:24:00 +1100 |
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In message <15954.22427.557293.353363@gargle.gargle.HOWL> you write: > Rusty Russell writes: > > D: This adds percpu support for modules. A module cannot have more > > D: percpu data than the base kernel does (on my kernel 5636 bytes). > > This limitation is quite horrible. > > Does the implementation have to be perfect? The per_cpu API can easily > be simulated using good old NR_CPUS arrays:
The problem is that then you have to have to know whether this is a per-cpu thing created in a module, or not, when you use it 8(
There are two things we can use to alleviate the problem. The first would be to put a minimal cap on the per-cpu data size (eg. 8k). The other possibility is to allocate on an object granularity, in which case the rule becomes "no single per-cpu object can be larger than XXX", but the cost is to write a mini allocator.
I agree with you (and John) about disliking the limitation, but is it worse than the current no per-cpu stuff in modules at all?
Thanks! Rusty. -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - 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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