On 10/20/2012 01:29 AM, Mel Gorman wrote: > I'm travelling at the moment so apologies that I have not followed up on > this. My problem is still the same with the patch - it changes more > headers than is necessary and it is sparsemem specific. At minimum, try > the suggestion of > > if (!early_pfn_valid(pfn)) { > pfn = ALIGN(pfn + MAX_ORDER_NR_PAGES, MAX_ORDER_NR_PAGES) - 1; > continue; > } Sorry I didn't catch this until v2... Is that ALIGN() correct? If pfn=3, then it would expand to: (3+MAX_ORDER_NR_PAGES+MAX_ORDER_NR_PAGES-1) & ~(MAX_ORDER_NR_PAGES-1) You would end up skipping the current MAX_ORDER_NR_PAGES area, and then one _extra_ because ALIGN() aligns up, and you're adding MAX_ORDER_NR_PAGES too. It doesn't matter unless you run in to a !early_valid_pfn() in the middle of a MAX_ORDER area, I guess. I think this would work, plus be a bit smaller: pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES) - 1; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>