Messages in this thread | | | Date | Fri, 16 Nov 2012 12:26:41 -0500 | From | Rik van Riel <> | Subject | Re: [PATCH 06/43] mm: numa: Make pte_numa() and pmd_numa() a generic implementation |
| |
On 11/16/2012 11:56 AM, Mel Gorman wrote:
>> b33467764d8a mm/migrate: Introduce migrate_misplaced_page() > > bolts onto the side of migration and introduces MIGRATE_FAULT which > should not have been necessary. Already complained about. > > The alternative uses the existing migrate_pages() function but has > different requirements for taking a reference to the page.
Indeed, NACK to b33467764d8a
Mel's tree implements this in a much cleaner way.
>> ca2ea0747a5b mm/mpol: Add MPOL_MF_LAZY > > We more or less share this except I backed out the userspace visible bits > in a separate patch because I didn't think it had been carefully reviewed > how an application should use it and if it was a good idea. Covered in an > earlier review.
Agreed, these bits should not be userspace visible, at least not for now.
>> cd203e33c39d mm/mpol: Add MPOL_MF_NOOP > > I have a patch that backs this out on the grounds that I don't think we > have adequately discussed if it was the correct userspace interface. I > know Peter put a lot of time into it so it's probably correct but > without man pages or spending time writing an example program that used > it, I played safe.
Ditto.
>> 6fe64360a759 mm: Only flush the TLB when clearing an accessible pte > > I missed this. Stupid stupid stupid! It would reduce the TLB flushes from > migration context.
However, Ingo's tree still incurs the double page fault for migrated pages. Both trees could use a little improvement in this area :)
>> e9df40bfeb25 x86/mm: Introduce pte_accessible() > > prot_none.
This one is x86 specific, and would work as well with Andrea's _PAGE_NUMA as it would with _PAGE_PROTNONE.
>> is a good foundation already with no WIP policy bits in it. >> >> Mel, could you please work on this basis, or point out the bits >> you don't agree with so I can fix it? >> > > My main hangup is the prot_none choice and I know it's something we have > butted heads on without progress. I feel it is a lot cleaner to have > the _PAGE_NUMA bit (even if it's PROT_NONE underneath) and the helpers > avoid function calls where possible.
I am pretty neutral on whether we use _PAGE_NUMA with _PAGE_PROTNONE underneath, or the slightly higher overhead actual prot_none stuff.
I can live with whichever of these Linus ends up merging.
-- All rights reversed
| |