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| author | Dan Williams <dan.j.williams@intel.com> | 2015-08-09 15:29:06 -0400 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2015-08-27 19:40:58 -0400 |
| commit | 033fbae988fcb67e5077203512181890848b8e90 (patch) | |
| tree | d0b9e418ab4f1df15435c098edf5ad687b426b3f /arch/tile/mm | |
| parent | 012dcef3f058385268630c0003e9b7f8dcafbeb4 (diff) | |
| download | linux-033fbae988fcb67e5077203512181890848b8e90.tar.bz2 | |
mm: ZONE_DEVICE for "device memory"
While pmem is usable as a block device or via DAX mappings to userspace
there are several usage scenarios that can not target pmem due to its
lack of struct page coverage. In preparation for "hot plugging" pmem
into the vmemmap add ZONE_DEVICE as a new zone to tag these pages
separately from the ones that are subject to standard page allocations.
Importantly "device memory" can be removed at will by userspace
unbinding the driver of the device.
Having a separate zone prevents allocation and otherwise marks these
pages that are distinct from typical uniform memory. Device memory has
different lifetime and performance characteristics than RAM. However,
since we have run out of ZONES_SHIFT bits this functionality currently
depends on sacrificing ZONE_DMA.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Jerome Glisse <j.glisse@gmail.com>
[hch: various simplifications in the arch interface]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'arch/tile/mm')
| -rw-r--r-- | arch/tile/mm/init.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c index 5bd252e3fdc5..d4e1fc41d06d 100644 --- a/arch/tile/mm/init.c +++ b/arch/tile/mm/init.c @@ -863,7 +863,7 @@ void __init mem_init(void) * memory to the highmem for now. */ #ifndef CONFIG_NEED_MULTIPLE_NODES -int arch_add_memory(u64 start, u64 size) +int arch_add_memory(u64 start, u64 size, bool for_device) { struct pglist_data *pgdata = &contig_page_data; struct zone *zone = pgdata->node_zones + MAX_NR_ZONES-1; |