Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [patch 3/4] cpu alloc: The allocator | Date | Mon, 6 Oct 2008 07:10:43 +1000 |
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On Friday 03 October 2008 22:48:32 Christoph Lameter wrote: > Andrew Morton wrote: > > But I'd have though that it would be possible to only allocate the > > storage for online CPUs. That would be a pretty significant win for > > some system configurations? > > We have tried that but currently the kernel (core and in particular arch > code) keeps state for all possible cpus in percpu segments. Would require > more extensive cleanup of numerous arches to do.
It shouldn't be a big win, since possible ~= online for most systems. And having all the per-cpu users register online and offline cpu callbacks is error prone and a PITA.
Rusty.
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