With hugepages, we store the hpte valid information in the pte page whose address is stored in the second half of the PMD. Use a write barrier to make sure clearing pmd busy bit and updating hpte valid info are ordered properly.
Signed-off-by: Aneesh Kumar K.V <[email protected]> --- arch/powerpc/mm/hugepage-hash64.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c index 826893fcb3a7..11f9a37ca2c6 100644 --- a/arch/powerpc/mm/hugepage-hash64.c +++ b/arch/powerpc/mm/hugepage-hash64.c @@ -172,8 +172,11 @@ repeat: mark_hpte_slot_valid(hpte_slot_array, index, slot); } /* - * No need to use ldarx/stdcx here + * The hpte valid is stored in the pgtable whose address is in the + * second half of the PMD. Order this against clearing of the busy bit in + * huge pmd. */ + smp_wmb(); *pmdp = __pmd(new_pmd & ~_PAGE_BUSY); return 0; } -- 1.9.1 _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
