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author | Usama Arif <usama.arif@bytedance.com> | 2023-09-13 13:53:58 +0300 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-04 20:32:30 +0300 |
commit | a9e34ea1f62c1e359ed197ec01d056c25edb2b61 (patch) | |
tree | b898f33e80ba1a93bc198e0f2a3bc1ca072d5ecd /mm/hugetlb_vmemmap.c | |
parent | 863803a7948c8e33e6a7b002017747ca83ecfd63 (diff) | |
download | linux-a9e34ea1f62c1e359ed197ec01d056c25edb2b61.tar.xz |
mm: hugetlb_vmemmap: use nid of the head page to reallocate it
Patch series "mm: hugetlb: Skip initialization of gigantic tail struct
pages if freed by HVO", v5.
This series moves the boot time initialization of tail struct pages of a
gigantic page to later on in the boot. Only the
HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page) - 1 tail struct pages
are initialized at the start. If HVO is successful, then no more tail
struct pages need to be initialized. For a 1G hugepage, this series avoid
initialization of 262144 - 63 = 262081 struct pages per hugepage.
When tested on a 512G system (allocating 500 1G hugepages), the kexec-boot
times with DEFERRED_STRUCT_PAGE_INIT enabled are:
- with patches, HVO enabled: 1.32 seconds
- with patches, HVO disabled: 2.15 seconds
- without patches, HVO enabled: 3.90 seconds
- without patches, HVO disabled: 3.58 seconds
This represents an approximately 70% reduction in boot time and will
significantly reduce server downtime when using a large number of gigantic
pages.
This patch (of 4):
If tail page prep and initialization is skipped, then the "start" page
will not contain the correct nid. Use the nid from first vmemap page.
Link: https://lkml.kernel.org/r/20230913105401.519709-1-usama.arif@bytedance.com
Link: https://lkml.kernel.org/r/20230913105401.519709-2-usama.arif@bytedance.com
Signed-off-by: Usama Arif <usama.arif@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb_vmemmap.c')
-rw-r--r-- | mm/hugetlb_vmemmap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 0bde38626d25..ad650c7b07ec 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -319,7 +319,7 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end, .reuse_addr = reuse, .vmemmap_pages = &vmemmap_pages, }; - int nid = page_to_nid((struct page *)start); + int nid = page_to_nid((struct page *)reuse); gfp_t gfp_mask = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; /* |