path: root/arch/s390
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authorDan Williams <dan.j.williams@intel.com>2015-08-09 15:29:06 -0400
committerDan Williams <dan.j.williams@intel.com>2015-08-27 19:40:58 -0400
commit033fbae988fcb67e5077203512181890848b8e90 (patch)
treed0b9e418ab4f1df15435c098edf5ad687b426b3f /arch/s390
parent012dcef3f058385268630c0003e9b7f8dcafbeb4 (diff)
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/s390')
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 76e873748b56..48ee78be88ba 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -168,7 +168,7 @@ void __init free_initrd_mem(unsigned long start, unsigned long end)
-int arch_add_memory(int nid, u64 start, u64 size)
+int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
unsigned long start_pfn = PFN_DOWN(start);