| Message ID | 20210204035043.36609-3-songmuchun@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Free some vmemmap pages of HugeTLB page | expand |
Hi: On 2021/2/4 11:50, Muchun Song wrote: > The option HUGETLB_PAGE_FREE_VMEMMAP allows for the freeing of > some vmemmap pages associated with pre-allocated HugeTLB pages. > For example, on X86_64 6 vmemmap pages of size 4KB each can be > saved for each 2MB HugeTLB page. 4094 vmemmap pages of size 4KB > each can be saved for each 1GB HugeTLB page. > > When a HugeTLB page is allocated or freed, the vmemmap array > representing the range associated with the page will need to be > remapped. When a page is allocated, vmemmap pages are freed > after remapping. When a page is freed, previously discarded > vmemmap pages must be allocated before remapping. > > The config option is introduced early so that supporting code > can be written to depend on the option. The initial version of > the code only provides support for x86-64. > > Like other code which frees vmemmap, this config option depends on > HAVE_BOOTMEM_INFO_NODE. The routine register_page_bootmem_info() is > used to register bootmem info. Therefore, make sure > register_page_bootmem_info is enabled if HUGETLB_PAGE_FREE_VMEMMAP > is defined. > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > Reviewed-by: Oscar Salvador <osalvador@suse.de> > Acked-by: Mike Kravetz <mike.kravetz@oracle.com> LGTM. Thanks. Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> > --- > arch/x86/mm/init_64.c | 2 +- > fs/Kconfig | 6 ++++++ > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 0a45f062826e..0435bee2e172 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1225,7 +1225,7 @@ static struct kcore_list kcore_vsyscall; > > static void __init register_page_bootmem_info(void) > { > -#ifdef CONFIG_NUMA > +#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP) > int i; > > for_each_online_node(i) > diff --git a/fs/Kconfig b/fs/Kconfig > index 97e7b77c9309..de87f234f1e9 100644 > --- a/fs/Kconfig > +++ b/fs/Kconfig > @@ -237,6 +237,12 @@ config HUGETLBFS > config HUGETLB_PAGE > def_bool HUGETLBFS > > +config HUGETLB_PAGE_FREE_VMEMMAP > + def_bool HUGETLB_PAGE > + depends on X86_64 > + depends on SPARSEMEM_VMEMMAP > + depends on HAVE_BOOTMEM_INFO_NODE > + > config MEMFD_CREATE > def_bool TMPFS || HUGETLBFS > >
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 0a45f062826e..0435bee2e172 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1225,7 +1225,7 @@ static struct kcore_list kcore_vsyscall; static void __init register_page_bootmem_info(void) { -#ifdef CONFIG_NUMA +#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP) int i; for_each_online_node(i) diff --git a/fs/Kconfig b/fs/Kconfig index 97e7b77c9309..de87f234f1e9 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -237,6 +237,12 @@ config HUGETLBFS config HUGETLB_PAGE def_bool HUGETLBFS +config HUGETLB_PAGE_FREE_VMEMMAP + def_bool HUGETLB_PAGE + depends on X86_64 + depends on SPARSEMEM_VMEMMAP + depends on HAVE_BOOTMEM_INFO_NODE + config MEMFD_CREATE def_bool TMPFS || HUGETLBFS