| Message ID | 20201113105952.11638-4-songmuchun@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Free some vmemmap pages of hugetlb page | expand |
On 11/13/20 2:59 AM, Muchun Song wrote: > The purpose of introducing HUGETLB_PAGE_FREE_VMEMMAP is to configure > whether to enable the feature of freeing unused vmemmap associated > with HugeTLB pages. Now only support x86. > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > --- > arch/x86/mm/init_64.c | 2 +- > fs/Kconfig | 14 ++++++++++++++ > 2 files changed, 15 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 976e8b9033c4..67e1bc99574f 100644 > --- a/fs/Kconfig > +++ b/fs/Kconfig > @@ -245,6 +245,20 @@ config HUGETLBFS > config HUGETLB_PAGE > def_bool HUGETLBFS > > +config HUGETLB_PAGE_FREE_VMEMMAP > + def_bool HUGETLB_PAGE > + depends on X86 > + depends on SPARSEMEM_VMEMMAP > + depends on HAVE_BOOTMEM_INFO_NODE > + help > + When using SPARSEMEM_VMEMMAP, the system can save up some memory Should that read, When using HUGETLB_PAGE_FREE_VMEMMAP, ... as the help message is for this config option.
On Thu, Nov 19, 2020 at 6:39 AM Mike Kravetz <mike.kravetz@oracle.com> wrote: > > On 11/13/20 2:59 AM, Muchun Song wrote: > > The purpose of introducing HUGETLB_PAGE_FREE_VMEMMAP is to configure > > whether to enable the feature of freeing unused vmemmap associated > > with HugeTLB pages. Now only support x86. > > > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > > --- > > arch/x86/mm/init_64.c | 2 +- > > fs/Kconfig | 14 ++++++++++++++ > > 2 files changed, 15 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 976e8b9033c4..67e1bc99574f 100644 > > --- a/fs/Kconfig > > +++ b/fs/Kconfig > > @@ -245,6 +245,20 @@ config HUGETLBFS > > config HUGETLB_PAGE > > def_bool HUGETLBFS > > > > +config HUGETLB_PAGE_FREE_VMEMMAP > > + def_bool HUGETLB_PAGE > > + depends on X86 > > + depends on SPARSEMEM_VMEMMAP > > + depends on HAVE_BOOTMEM_INFO_NODE > > + help > > + When using SPARSEMEM_VMEMMAP, the system can save up some memory > > Should that read, > > When using HUGETLB_PAGE_FREE_VMEMMAP, ... > > as the help message is for this config option. Got it. Thanks > > -- > Mike Kravetz
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 976e8b9033c4..67e1bc99574f 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -245,6 +245,20 @@ config HUGETLBFS config HUGETLB_PAGE def_bool HUGETLBFS +config HUGETLB_PAGE_FREE_VMEMMAP + def_bool HUGETLB_PAGE + depends on X86 + depends on SPARSEMEM_VMEMMAP + depends on HAVE_BOOTMEM_INFO_NODE + help + When using SPARSEMEM_VMEMMAP, the system can save up some memory + from pre-allocated HugeTLB pages when they are not used. 6 pages + per 2MB HugeTLB page and 4094 per 1GB HugeTLB page. + + When the pages are going to be used or freed up, the vmemmap array + representing that range needs to be remapped again and the pages + we discarded earlier need to be rellocated again. + config MEMFD_CREATE def_bool TMPFS || HUGETLBFS
The purpose of introducing HUGETLB_PAGE_FREE_VMEMMAP is to configure whether to enable the feature of freeing unused vmemmap associated with HugeTLB pages. Now only support x86. Signed-off-by: Muchun Song <songmuchun@bytedance.com> --- arch/x86/mm/init_64.c | 2 +- fs/Kconfig | 14 ++++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-)