This currently uses optimised bit-hacks to avoid conditional branches
etc. For the purposes of the RFC, let's not get bogged down in those
details - temporarily just drop the bit hacking.
Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
---
include/linux/gfp.h | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 6bb1a5a7a4ae3392c1cd39cb79271e05512adbeb..23289aa54b6c38a71a908e5a6e034828a75a3b66 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -14,25 +14,20 @@ struct mempolicy;
/* Convert GFP flags to their corresponding migrate type */
#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
-#define GFP_MOVABLE_SHIFT 3
static inline int gfp_migratetype(const gfp_t gfp_flags)
{
VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
- BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
- BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
- BUILD_BUG_ON((___GFP_RECLAIMABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_RECLAIMABLE);
- BUILD_BUG_ON(((___GFP_MOVABLE | ___GFP_RECLAIMABLE) >>
- GFP_MOVABLE_SHIFT) != MIGRATE_HIGHATOMIC);
if (unlikely(page_group_by_mobility_disabled))
return MIGRATE_UNMOVABLE;
- /* Group based on mobility */
- return (__force unsigned long)(gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
+ switch (gfp_flags & GFP_MOVABLE_MASK) {
+ case __GFP_RECLAIMABLE: return MIGRATE_RECLAIMABLE;
+ case __GFP_MOVABLE: return MIGRATE_MOVABLE;
+ default: return MIGRATE_UNMOVABLE;
+ }
}
-#undef GFP_MOVABLE_MASK
-#undef GFP_MOVABLE_SHIFT
static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
{
--
2.49.0.rc1.451.g8f38331e32-goog
