diff options
| author | Usama Arif <usama.arif@bytedance.com> | 2023-09-13 11:54:01 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-04 10:32:30 -0700 |
| commit | fde1c4ecf91640e5a95ec36b71ec2e8ec379ce40 (patch) | |
| tree | ebbd7d77db3e2926ae632857ff6ee132e87c11da /mm/hugetlb_vmemmap.c | |
| parent | 77e6c43e137c130138c3fbadc847351a83c4befe (diff) | |
mm: hugetlb: skip initialization of gigantic tail struct pages if freed by HVO
The new boot flow when it comes to initialization of gigantic pages is as
follows:
- At boot time, for a gigantic page during __alloc_bootmem_hugepage, the
region after the first struct page is marked as noinit.
- This results in only the first struct page to be initialized in
reserve_bootmem_region. As the tail struct pages are not initialized at
this point, there can be a significant saving in boot time if HVO
succeeds later on.
- Later on in the boot, the head page is prepped and the first
HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page) - 1 tail struct pages
are initialized.
- HVO is attempted. If it is not successful, then the rest of the tail
struct pages are initialized. If it is successful, no more tail struct
pages need to be initialized saving significant boot time.
The WARN_ON for increased ref count in gather_bootmem_prealloc was changed
to a VM_BUG_ON. This is OK as there should be no speculative references
this early in boot process. The VM_BUG_ON's are there just in case such
code is introduced.
[akpm@linux-foundation.org: make it nicer for 80 cols]
Link: https://lkml.kernel.org/r/20230913105401.519709-5-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 ad650c7b07ec..76682d1d79a7 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -588,7 +588,7 @@ static int __init hugetlb_vmemmap_init(void) const struct hstate *h; /* HUGETLB_VMEMMAP_RESERVE_SIZE should cover all used struct pages */ - BUILD_BUG_ON(__NR_USED_SUBPAGE * sizeof(struct page) > HUGETLB_VMEMMAP_RESERVE_SIZE); + BUILD_BUG_ON(__NR_USED_SUBPAGE > HUGETLB_VMEMMAP_RESERVE_PAGES); for_each_hstate(h) { if (hugetlb_vmemmap_optimizable(h)) { |