Messages in this thread | | | Date | Sun, 14 Sep 2008 16:12:30 +0200 | From | Ingo Molnar <> | Subject | Re: [patch 1/2] x86: track memtype for RAM in page struct |
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* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> wrote:
> From: Suresh Siddha <suresh.b.siddha@intel.com> > Subject: [patch 1/2] x86: track memtype for RAM in page struct > > Track the memtype for RAM pages in page struct instead of using the > memtype list. This avoids the explosion in the number of entries in > memtype list (of the order of 20,000 with AGP) and makes the PAT > tracking simpler. We are using PG_arch_1 bit in page->flags.
this is in contradiction to this comment:
> /* > + * RED-PEN: TODO: Add PageReserved() check aswell here, > + * once we add SetPageReserved() to all the drivers using > + * set_memory_* or set_pages_*
if it's marked PG_arch_1, why is there any need for PageReserved?
> + * > + * This will help prevent accidentally freeing pages > + * before setting the attribute back to WB.
setting it PageReserved is a hack. We should set it PG_arch_1 and extend the page allocator to emit a kernel warning if a PG_arch_1 page is freed.
Ingo
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