diff options
| author |   Mel Gorman <mgorman@suse.de> | 2014-06-04 16:06:30 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:53:55 -0700 |
| commit | c46a7c817e662a820373bb76b88d0ad67d6abe5d (patch) | |
| tree | 41a7d24c818c9cfe71f335f7fdae162896aa3b23 /include/linux/swapops.h | |
| parent | x86: require x86-64 for automatic NUMA balancing (diff) | |
| download | linux-dev-c46a7c817e662a820373bb76b88d0ad67d6abe5d.tar.xz linux-dev-c46a7c817e662a820373bb76b88d0ad67d6abe5d.zip | |
x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels
_PAGE_NUMA is currently an alias of _PROT_PROTNONE to trap NUMA hinting
faults on x86. Care is taken such that _PAGE_NUMA is used only in
situations where the VMA flags distinguish between NUMA hinting faults
and prot_none faults. This decision was x86-specific and conceptually
it is difficult requiring special casing to distinguish between PROTNONE
and NUMA ptes based on context.
Fundamentally, we only need the _PAGE_NUMA bit to tell the difference
between an entry that is really unmapped and a page that is protected
for NUMA hinting faults as if the PTE is not present then a fault will
be trapped.
Swap PTEs on x86-64 use the bits after _PAGE_GLOBAL for the offset.
This patch shrinks the maximum possible swap size and uses the bit to
uniquely distinguish between NUMA hinting ptes and swap ptes.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/swapops.h')
| -rw-r--r-- | include/linux/swapops.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/swapops.h b/include/linux/swapops.h index c0f75261a728..6adfb7bfbf44 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -54,7 +54,7 @@ static inline pgoff_t swp_offset(swp_entry_t entry) /* check whether a pte points to a swap entry */ static inline int is_swap_pte(pte_t pte) { - return !pte_none(pte) && !pte_present(pte) && !pte_file(pte); + return !pte_none(pte) && !pte_present_nonuma(pte) && !pte_file(pte); } #endif |