Messages in this thread Patch in this message | | | Date | Fri, 3 Mar 2006 12:04:08 +1100 | From | 'David Gibson' <> | Subject | hugepage: Fix hugepage logic in free_pgtables() harder |
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Sigh. Turns out the hugepage logic in free_pgtables() was doubly broken. The loop coalescing multiple normal page VMAs into one call to free_pgd_range() had an off by one error, which could mean it would coalesce one hugepage VMA into the same bundle (checking 'vma' not 'next' in the loop). I transferred this bug into the new is_vm_hugetlb_page() based version. Here's the fix.
This one didn't bite on powerpc previously for the same reason the is_hugepage_only_range() problem didn't: powerpc's hugetlb_free_pgd_range() is identical to free_pgd_range(). It didn't bite on ia64 because the hugepage region is distant enough from any other region that the separated PMD_SIZE distance test would always prevent coalescing the two together.
No libhugetlbfs testsuite regressions (ppc64, POWER5).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Index: working-2.6/mm/memory.c =================================================================== --- working-2.6.orig/mm/memory.c 2006-03-03 11:39:33.000000000 +1100 +++ working-2.6/mm/memory.c 2006-03-03 11:39:50.000000000 +1100 @@ -285,7 +285,7 @@ void free_pgtables(struct mmu_gather **t * Optimization: gather nearby vmas into one call down */ while (next && next->vm_start <= vma->vm_end + PMD_SIZE - && !is_vm_hugetlb_page(vma)) { + && !is_vm_hugetlb_page(next)) { vma = next; next = vma->vm_next; anon_vma_unlink(vma);
-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson - 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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