Messages in this thread | | | Subject | Re: [patch 1] Xen core patch : ptep_establish_new | Date | Thu, 18 Nov 2004 10:29:29 +0000 | From | Keir Fraser <> |
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> > On Wed, Nov 17, 2004 at 11:46:50PM +0000, Ian Pratt wrote: > > > > > > This patch adds 'ptep_establish_new', in keeping with the > > > existing 'ptep_establish', but for use where a mapping is being > > > established where there was previously none present. This > > > function is useful (rather than just using set_pte) because > > > having the virtual address available enables a very important > > > optimisation for arch-xen. We introduce > > > HAVE_ARCH_PTEP_ESTABLISH_NEW and define a generic implementation > > > in asm-generic/pgtable.h, following the pattern of the existing > > > ptep_establish. > > > > What would be the problem of always passing the virtual address to > > ptep_establish? We already have a rather twisted maze of pte manipulation > > macros. > > ptep_establish already takes a virtual address. Perhaps you mean > 'set_pte'? That would work, but is a much bigger change that > would impact all architectures. I think introducing > ptep_establish_new is cleaner.
Also, we want to know which PTE updates are to a virtual address within the *current* address space. Just adding a VA to every set_pte use wouldn't tell us that (without yet another parameter ;-).
-- Keir - 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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