[PATCH -V9 10/20] powerpc: Update find_linux_pte_or_hugepte to handle transparent hugepages
From: Aneesh Kumar K.V <hidden>
Date: 2013-05-22 16:58:27
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: "Aneesh Kumar K.V" <redacted> Reviewed-by: David Gibson <redacted> Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/mm/hugetlbpage.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 2865077..4928204 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c@@ -936,30 +936,50 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift pg = pgdir + pgd_index(ea); - if (pgd_huge(*pg)) { + /* + * we should first check for none. That takes care of a + * a parallel hugetlb or THP pagefault moving none entries + * to respective types. + */ + if (pgd_none(*pg)) + return NULL; + else if (pgd_huge(*pg)) { ret_pte = (pte_t *) pg; goto out; } else if (is_hugepd(pg)) hpdp = (hugepd_t *)pg; - else if (!pgd_none(*pg)) { + else { pdshift = PUD_SHIFT; pu = pud_offset(pg, ea); - if (pud_huge(*pu)) { + if (pud_none(*pu)) + return NULL; + else if (pud_huge(*pu)) { ret_pte = (pte_t *) pu; goto out; } else if (is_hugepd(pu)) hpdp = (hugepd_t *)pu; - else if (!pud_none(*pu)) { + else { pdshift = PMD_SHIFT; pm = pmd_offset(pu, ea); + /* + * A hugepage collapse is captured by pmd_none, because + * it mark the pmd none and do a hpte invalidate. + * + * A hugepage split is captured by pmd_trans_splitting + * because we mark the pmd trans splitting and do a + * hpte invalidate + * + */ + if (pmd_none(*pm) || pmd_trans_splitting(*pm)) + return NULL; - if (pmd_huge(*pm)) { + if (pmd_huge(*pm) || pmd_large(*pm)) { ret_pte = (pte_t *) pm; goto out; } else if (is_hugepd(pm)) hpdp = (hugepd_t *)pm; - else if (!pmd_none(*pm)) + else return pte_offset_kernel(pm, ea); } }
--
1.8.1.2