]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
mm, hugetlb: remove hugepages_treat_as_movable sysctl
authorMichal Hocko <mhocko@suse.com>
Thu, 1 Feb 2018 00:17:10 +0000 (16:17 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 1 Feb 2018 01:18:37 +0000 (17:18 -0800)
commitd6cb41cc44c63492702281b1d329955ca767d399
tree785e8c630913c6408b6a9e2d487aa06209ec0785
parenta4ef87684108e5fef38cf289ee360f9b87a53cfd
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>
Documentation/sysctl/vm.txt
include/linux/hugetlb.h
kernel/sysctl.c
mm/hugetlb.c