diff options
| author |   Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2019-03-05 15:47:44 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-05 21:07:19 -0800 |
| commit | 9a4e9f3b2d7393d50256762c21e7466b4b6b1c9c (patch) | |
| tree | 9bd45af1767a3bbdc782bac767c18a189da9d7b9 /include/linux/mm.h | |
| parent | mm/cma: add PF flag to force non cma alloc (diff) | |
| download | linux-dev-9a4e9f3b2d7393d50256762c21e7466b4b6b1c9c.tar.xz linux-dev-9a4e9f3b2d7393d50256762c21e7466b4b6b1c9c.zip | |
mm: update get_user_pages_longterm to migrate pages allocated from CMA region
This patch updates get_user_pages_longterm to migrate pages allocated
out of CMA region. This makes sure that we don't keep non-movable pages
(due to page reference count) in the CMA area.
This will be used by ppc64 in a later patch to avoid pinning pages in
the CMA region. ppc64 uses CMA region for allocation of the hardware
page table (hash page table) and not able to migrate pages out of CMA
region results in page table allocation failures.
One case where we hit this easy is when a guest using a VFIO passthrough
device. VFIO locks all the guest's memory and if the guest memory is
backed by CMA region, it becomes unmovable resulting in fragmenting the
CMA and possibly preventing other guests from allocation a large enough
hash page table.
NOTE: We allocate the new page without using __GFP_THISNODE
Link: http://lkml.kernel.org/r/20190114095438.32470-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 80bb6408fe73..20ec56f8e2bb 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1536,7 +1536,8 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, int *locked); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); -#ifdef CONFIG_FS_DAX + +#if defined(CONFIG_FS_DAX) || defined(CONFIG_CMA) long get_user_pages_longterm(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas); |