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authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2023-07-25 00:37:57 +0530
committerAndrew Morton <akpm@linux-foundation.org>2023-08-18 10:12:55 -0700
commitf2b79c0d79683d552369bb9a7282c1f0226fc566 (patch)
tree51b5c1a2e4f1612e59b2b82654c35d8e45bc172c /Documentation/mm
parent368a0590d954a659b16ab945328ada0cc10f93a0 (diff)
powerpc/book3s64/radix: add support for vmemmap optimization for radix
With 2M PMD-level mapping, we require 32 struct pages and a single vmemmap page can contain 1024 struct pages (PAGE_SIZE/sizeof(struct page)). Hence with 64K page size, we don't use vmemmap deduplication for PMD-level mapping. [aneesh.kumar@linux.ibm.com: ppc64: don't include radix headers if CONFIG_PPC_RADIX_MMU=n] Link: https://lkml.kernel.org/r/87zg3jw8km.fsf@linux.ibm.com Link: https://lkml.kernel.org/r/20230724190759.483013-12-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation/mm')
-rw-r--r--Documentation/mm/vmemmap_dedup.rst1
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/mm/vmemmap_dedup.rst b/Documentation/mm/vmemmap_dedup.rst
index a4b12ff906c4..c573e08b5043 100644
--- a/Documentation/mm/vmemmap_dedup.rst
+++ b/Documentation/mm/vmemmap_dedup.rst
@@ -210,6 +210,7 @@ the device (altmap).
The following page sizes are supported in DAX: PAGE_SIZE (4K on x86_64),
PMD_SIZE (2M on x86_64) and PUD_SIZE (1G on x86_64).
+For powerpc equivalent details see Documentation/powerpc/vmemmap_dedup.rst
The differences with HugeTLB are relatively minor.