Messages in this thread | | | Date | Wed, 14 Jul 2010 01:44:23 +0900 | From | Minchan Kim <> | Subject | Re: [RFC] Tight check of pfn_valid on sparsemem |
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Hi, Dave.
On Tue, Jul 13, 2010 at 09:35:33AM -0700, Dave Hansen wrote: > On Wed, 2010-07-14 at 00:43 +0900, Minchan Kim wrote: > > 3 is not a big deal than 2 about memory usage. > > If the system use memory space fully(MAX_PHYSMEM_BITS 31), it just consumes > > 1024(128 * 8) byte. So now I think best solution is 2. > > > > Russell. What do you think about it? > > I'm not Russell, but I'll tell you what I think. :) >
No problem. :)
> Make the sections 16MB. You suggestion to add the start/end pfns
I hope so.
> _doubles_ the size of the structure, and its size overhead. We have > systems with a pretty tremendous amount of memory with 16MB sections.
Yes. it does in several GB server system.
> > If you _really_ can't make the section size smaller, and the vast > majority of the sections are fully populated, you could hack something > in. We could, for instance, have a global list that's mostly readonly > which tells you which sections need to be have their sizes closely > inspected. That would work OK if, for instance, you only needed to > check a couple of memory sections in the system. It'll start to suck if > you made the lists very long.
Thanks for advise. As I say, I hope Russell accept 16M section.
> > -- Dave >
-- Kind regards, Minchan Kim
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