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authorMichal Hocko <mhocko@suse.com>2018-01-31 16:17:10 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 17:18:37 -0800
commitd6cb41cc44c63492702281b1d329955ca767d399 (patch)
tree785e8c630913c6408b6a9e2d487aa06209ec0785 /mm/hugetlb.c
parenta4ef87684108e5fef38cf289ee360f9b87a53cfd (diff)
downloadop-kernel-dev-d6cb41cc44c63492702281b1d329955ca767d399.zip
op-kernel-dev-d6cb41cc44c63492702281b1d329955ca767d399.tar.gz
mm, hugetlb: remove hugepages_treat_as_movable sysctl
hugepages_treat_as_movable has been introduced by 396faf0303d2 ("Allow huge page allocations to use GFP_HIGH_MOVABLE") to allow hugetlb allocations from ZONE_MOVABLE even when hugetlb pages were not migrateable. The purpose of the movable zone was different at the time. It aimed at reducing memory fragmentation and hugetlb pages being long lived and large werre not contributing to the fragmentation so it was acceptable to use the zone back then. Things have changed though and the primary purpose of the zone became migratability guarantee. If we allow non migrateable hugetlb pages to be in ZONE_MOVABLE memory hotplug might fail to offline the memory. Remove the knob and only rely on hugepage_migration_supported to allow movable zones. Mel said: : Primarily it was aimed at allowing the hugetlb pool to safely shrink with : the ability to grow it again. The use case was for batched jobs, some of : which needed huge pages and others that did not but didn't want the memory : useless pinned in the huge pages pool. : : I suspect that more users rely on THP than hugetlbfs for flexible use of : huge pages with fallback options so I think that removing the option : should be ok. Link: http://lkml.kernel.org/r/20171003072619.8654-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Alexandru Moise <00moses.alexander00@gmail.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Alexandru Moise <00moses.alexander00@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
-rw-r--r--mm/hugetlb.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1e6a5ad..4137fb6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -36,8 +36,6 @@
#include <linux/userfaultfd_k.h>
#include "internal.h"
-int hugepages_treat_as_movable;
-
int hugetlb_max_hstate __read_mostly;
unsigned int default_hstate_idx;
struct hstate hstates[HUGE_MAX_HSTATE];
@@ -926,7 +924,7 @@ retry_cpuset:
/* Movability of hugepages depends on migration support. */
static inline gfp_t htlb_alloc_mask(struct hstate *h)
{
- if (hugepages_treat_as_movable || hugepage_migration_supported(h))
+ if (hugepage_migration_supported(h))
return GFP_HIGHUSER_MOVABLE;
else
return GFP_HIGHUSER;
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