The patch titled
Subject: mm, page_alloc: skip ->watermark_boost for atomic order-0 allocations-fix
has been added to the -mm tree. Its filename is
mm-page_alloc-skip-watermark_boost-for-atomic-order-0-allocations-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-skip-watermark_boost-for-atomic-order-0-allocations-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-skip-watermark_boost-for-atomic-order-0-allocations-fix.patch
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------------------------------------------------------
From: Charan Teja Kalla <charante@xxxxxxxxxxxxxx>
Subject: mm, page_alloc: skip ->watermark_boost for atomic order-0 allocations-fix
fix suggested by Mel Gorman
Link: http://lkml.kernel.org/r/31556793-57b1-1c21-1a9d-22674d9bd938@xxxxxxxxxxxxxx
Signed-off-by: Charan Teja Reddy <charante@xxxxxxxxxxxxxx>
Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 36 ++++++++++++++++++++----------------
1 file changed, 20 insertions(+), 16 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-skip-watermark_boost-for-atomic-order-0-allocations-fix
+++ a/mm/page_alloc.c
@@ -3580,7 +3580,7 @@ bool zone_watermark_ok(struct zone *z, u
static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
unsigned long mark, int highest_zoneidx,
- unsigned int alloc_flags)
+ unsigned int alloc_flags, gfp_t gfp_mask)
{
long free_pages = zone_page_state(z, NR_FREE_PAGES);
long cma_pages = 0;
@@ -3602,8 +3602,23 @@ static inline bool zone_watermark_fast(s
mark + z->lowmem_reserve[highest_zoneidx])
return true;
- return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
- free_pages);
+ if (__zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
+ free_pages))
+ return true;
+ /*
+ * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
+ * when checking the min watermark. The min watermark is the
+ * point where boosting is ignored so that kswapd is woken up
+ * when below the low watermark.
+ */
+ if (unlikely(!order && (gfp_mask & __GFP_ATOMIC) && z->watermark_boost
+ && ((alloc_flags & ALLOC_WMARK_MASK) == WMARK_MIN))) {
+ mark = z->_watermark[WMARK_MIN];
+ return __zone_watermark_ok(z, order, mark, highest_zoneidx,
+ alloc_flags, free_pages);
+ }
+
+ return false;
}
bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
@@ -3746,20 +3761,9 @@ retry:
}
mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
- /*
- * Allow GFP_ATOMIC order-0 allocations to exclude the
- * zone->watermark_boost in their watermark calculations.
- * We rely on the ALLOC_ flags set for GFP_ATOMIC requests in
- * gfp_to_alloc_flags() for this. Reason not to use the
- * GFP_ATOMIC directly is that we want to fall back to slow path
- * thus wake up kswapd.
- */
- if (unlikely(!order && !(alloc_flags & ALLOC_WMARK_MASK) &&
- (alloc_flags & (ALLOC_HARDER | ALLOC_HIGH)))) {
- mark = zone->_watermark[WMARK_MIN];
- }
if (!zone_watermark_fast(zone, order, mark,
- ac->highest_zoneidx, alloc_flags)) {
+ ac->highest_zoneidx, alloc_flags,
+ gfp_mask)) {
int ret;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
_
Patches currently in -mm which might be from charante@xxxxxxxxxxxxxx are
mm-page_alloc-skip-waternark_boost-for-atomic-order-0-allocations.patch
mm-page_alloc-skip-watermark_boost-for-atomic-order-0-allocations-fix.patch
