diff options
| author | Hugh Dickins <hughd@google.com> | 2016-01-10 03:54:59 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-01-12 03:03:53 +0300 |
| commit | 2f10f1a7884e97a68e52c4b6f7866e29cf3fe7e6 (patch) | |
| tree | cd886883448dc68d534d3127b3c5074efd472254 | |
| parent | 44734f23de2465c3c0d39e4a16df7735b23fd142 (diff) | |
| download | linux-2f10f1a7884e97a68e52c4b6f7866e29cf3fe7e6.tar.xz | |
powerpc/mm: fix _PAGE_SWP_SOFT_DIRTY breaking swapoff
Swapoff after swapping hangs on the G5, when CONFIG_CHECKPOINT_RESTORE=y
but CONFIG_MEM_SOFT_DIRTY is not set. That's because the non-zero
_PAGE_SWP_SOFT_DIRTY bit, added by CONFIG_HAVE_ARCH_SOFT_DIRTY=y, is not
discounted when CONFIG_MEM_SOFT_DIRTY is not set: so swap ptes cannot be
recognized.
(I suspect that the peculiar dependence of HAVE_ARCH_SOFT_DIRTY on
CHECKPOINT_RESTORE in arch/powerpc/Kconfig comes from an incomplete
attempt to solve this problem.)
It's true that the relationship between CONFIG_HAVE_ARCH_SOFT_DIRTY and
and CONFIG_MEM_SOFT_DIRTY is too confusing, and it's true that swapoff
should be made more robust; but nevertheless, fix up the powerpc ifdefs
as x86_64 and s390 (which met the same problem) have them, defining the
bits as 0 if CONFIG_MEM_SOFT_DIRTY is not set.
Fixes: 7207f43665b8 ("powerpc/mm: Add page soft dirty tracking")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/hash.h | 5 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable.h | 9 |
2 files changed, 11 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index 9e861b4378bd..2ff8b3df553d 100644 --- a/arch/powerpc/include/asm/book3s/64/hash.h +++ b/arch/powerpc/include/asm/book3s/64/hash.h @@ -33,7 +33,12 @@ #define _PAGE_F_GIX_SHIFT 12 #define _PAGE_F_SECOND 0x08000 /* Whether to use secondary hash or not */ #define _PAGE_SPECIAL 0x10000 /* software: special page */ + +#ifdef CONFIG_MEM_SOFT_DIRTY #define _PAGE_SOFT_DIRTY 0x20000 /* software: software dirty tracking */ +#else +#define _PAGE_SOFT_DIRTY 0x00000 +#endif /* * THP pages can't be special. So use the _PAGE_SPECIAL diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 8e040c42e931..b3a5badab69f 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -167,8 +167,13 @@ static inline void pgd_set(pgd_t *pgdp, unsigned long val) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) & ~_PAGE_PTE }) #define __swp_entry_to_pte(x) __pte((x).val | _PAGE_PTE) -#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY +#ifdef CONFIG_MEM_SOFT_DIRTY #define _PAGE_SWP_SOFT_DIRTY (1UL << (SWP_TYPE_BITS + _PAGE_BIT_SWAP_TYPE)) +#else +#define _PAGE_SWP_SOFT_DIRTY 0UL +#endif /* CONFIG_MEM_SOFT_DIRTY */ + +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY static inline pte_t pte_swp_mksoft_dirty(pte_t pte) { return __pte(pte_val(pte) | _PAGE_SWP_SOFT_DIRTY); @@ -181,8 +186,6 @@ static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) { return __pte(pte_val(pte) & ~_PAGE_SWP_SOFT_DIRTY); } -#else -#define _PAGE_SWP_SOFT_DIRTY 0 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ void pgtable_cache_add(unsigned shift, void (*ctor)(void *)); |