__GFP_HIGH aliases to ALLOC_HIGH but the name does not really hint
what it means. As ALLOC_HIGH is internal to the allocator, rename
it to ALLOC_MIN_RESERVE to document that the min reserves can
be depleted.
Signed-off-by: Mel Gorman <[email protected]>
---
mm/internal.h | 4 +++-
mm/page_alloc.c | 8 ++++----
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index 6b7ef495b56d..d503e57a57a1 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -744,7 +744,9 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone,
#endif
#define ALLOC_HARDER 0x10 /* try to alloc harder */
-#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
+#define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50%
+ * of the min watermark.
+ */
#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
#ifdef CONFIG_ZONE_DMA32
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 218b28ee49ed..3b37909617bc 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3981,7 +3981,7 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
/* free_pages may go negative - that's OK */
free_pages -= __zone_watermark_unusable_free(z, order, alloc_flags);
- if (alloc_flags & ALLOC_HIGH)
+ if (alloc_flags & ALLOC_MIN_RESERVE)
min -= min / 2;
if (unlikely(alloc_harder)) {
@@ -4823,18 +4823,18 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
/*
- * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
+ * __GFP_HIGH is assumed to be the same as ALLOC_MIN_RESERVE
* and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
* to save two branches.
*/
- BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
+ BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_MIN_RESERVE);
BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM != (__force gfp_t) ALLOC_KSWAPD);
/*
* The caller may dip into page reserves a bit more if the caller
* cannot run direct reclaim, or if the caller has realtime scheduling
* policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
- * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
+ * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_MIN_RESERVE(__GFP_HIGH).
*/
alloc_flags |= (__force int)
(gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM));
--
2.35.3
On 11/29/22 16:16, Mel Gorman wrote:
> __GFP_HIGH aliases to ALLOC_HIGH but the name does not really hint
> what it means. As ALLOC_HIGH is internal to the allocator, rename
> it to ALLOC_MIN_RESERVE to document that the min reserves can
> be depleted.
>
> Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>