Messages in this thread | | | Date | Wed, 21 Mar 2007 16:46:33 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 1/3] add pfn_valid_within helper for sub-MAX_ORDER hole detection |
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On Thu, 22 Mar 2007 10:23:27 +1100 Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> Andy Whitcroft wrote: > > Generally we work under the assumption that memory the mem_map > > array is contigious and valid out to MAX_ORDER_NR_PAGES block > > of pages, ie. that if we have validated any page within this > > MAX_ORDER_NR_PAGES block we need not check any other. This is not > > true when CONFIG_HOLES_IN_ZONE is set and we must check each and > > every reference we make from a pfn. > > > > Add a pfn_valid_within() helper which should be used when scanning > > pages within a MAX_ORDER_NR_PAGES block when we have already > > checked the validility of the block normally with pfn_valid(). > > This can then be optimised away when we do not have holes within > > a MAX_ORDER_NR_PAGES block of pages. > > Nice cleanup. Horrible name ;) Calls read like "is the pfn valid > within pfn".
yeah
> I can't think of anything really good, but I think, say, > pfn_valid_within_block or pfn_valid_within_valid_block would be a > bit better. You still get a slight net savings in keystrokes!
Neither of those identifiers seem to really fit, and I can't think of anything suitable either. Oh well, at least pfn_valid_within() has a nice comment explaining what it does. - 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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