From: Mel Gorman Date: Mon, 16 Dec 2013 23:44:43 +0000 (+1100) Subject: mm: clear pmd_numa before invalidating X-Git-Tag: next-20131220~2^2~272 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=38eef1a41e54841a38cd0198e8a59a0ffa922093;p=karo-tx-linux.git mm: clear pmd_numa before invalidating On x86, PMD entries are similar to _PAGE_PROTNONE protection and are handled as NUMA hinting faults. The following two page table protection bits are what defines them _PAGE_NUMA:set _PAGE_PRESENT:clear A PMD is considered present if any of the _PAGE_PRESENT, _PAGE_PROTNONE, _PAGE_PSE or _PAGE_NUMA bits are set. If pmdp_invalidate encounters a pmd_numa, it clears the present bit leaving _PAGE_NUMA which will be considered not present by the CPU but present by pmd_present. The existing caller of pmdp_invalidate should handle it but it's an inconsistent state for a PMD. This patch keeps the state consistent when calling pmdp_invalidate. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Alex Thorlton Cc: Signed-off-by: Andrew Morton --- diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index cbb38545d9d6..e84cad27a801 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -191,6 +191,9 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { + pmd_t entry = *pmdp; + if (pmd_numa(entry)) + entry = pmd_mknonnuma(entry); set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(*pmdp)); flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); }