summaryrefslogtreecommitdiff
path: root/mm/sparse.c
diff options
context:
space:
mode:
authorMuchun Song <songmuchun@bytedance.com>2022-06-17 21:56:49 +0800
committerakpm <akpm@linux-foundation.org>2022-07-03 18:08:49 -0700
commited7802dd48f7a507213cbb95bb4c6f1fe134eb5d (patch)
tree51bcf8b6bb3b8b52190cb11c9cafc6d494c30578 /mm/sparse.c
parentceff9d3354e95ca17e12ad869acea5407cc467f9 (diff)
mm: memory_hotplug: enumerate all supported section flags
Patch series "make hugetlb_optimize_vmemmap compatible with memmap_on_memory", v3. This series makes hugetlb_optimize_vmemmap compatible with memmap_on_memory. This patch (of 2): We are almost running out of section flags, only one bit is available in the worst case (powerpc with 256k pages). However, there are still some free bits (in ->section_mem_map) on other architectures (e.g. x86_64 has 10 bits available, arm64 has 8 bits available with worst case of 64K pages). We have hard coded those numbers in code, it is inconvenient to use those bits on other architectures except powerpc. So transfer those section flags to enumeration to make it easy to add new section flags in the future. Also, move SECTION_TAINT_ZONE_DEVICE into the scope of CONFIG_ZONE_DEVICE to save a bit on non-zone-device case. [songmuchun@bytedance.com: replace enum with defines per David] Link: https://lkml.kernel.org/r/20220620110616.12056-2-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-1-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-2-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/sparse.c')
-rw-r--r--mm/sparse.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/sparse.c b/mm/sparse.c
index cb3bfae64036..e5a8a3a0edd7 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -281,7 +281,7 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p
{
unsigned long coded_mem_map =
(unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
- BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT));
+ BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT);
BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
return coded_mem_map;
}