| Message ID | 20201213154534.54826-9-songmuchun@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Free some vmemmap pages of HugeTLB page | expand |
On Sun, Dec 13, 2020 at 11:45:31PM +0800, Muchun Song wrote: > Add a kernel parameter hugetlb_free_vmemmap to disable the feature of > freeing unused vmemmap pages associated with each hugetlb page on boot. I guess this should read "to enable the feature"? AFAICS, it is disabled by default. > Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> > --- > Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ > Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ > arch/x86/mm/init_64.c | 8 ++++++-- > include/linux/hugetlb.h | 19 +++++++++++++++++++ > mm/hugetlb_vmemmap.c | 16 ++++++++++++++++ > 5 files changed, 53 insertions(+), 2 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 3ae25630a223..9e6854f21d55 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1551,6 +1551,15 @@ > Documentation/admin-guide/mm/hugetlbpage.rst. > Format: size[KMG] > > + hugetlb_free_vmemmap= > + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, > + this controls freeing unused vmemmap pages associated > + with each HugeTLB page. > + Format: { on | off (default) } > + > + on: enable the feature > + off: disable the feature > + > hung_task_panic= > [KNL] Should the hung task detector generate panics. > Format: 0 | 1 > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst > index f7b1c7462991..3a23c2377acc 100644 > --- a/Documentation/admin-guide/mm/hugetlbpage.rst > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst > @@ -145,6 +145,9 @@ default_hugepagesz > > will all result in 256 2M huge pages being allocated. Valid default > huge page size is architecture dependent. > +hugetlb_free_vmemmap > + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing > + unused vmemmap pages associated with each HugeTLB page. > > When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` > indicates the current number of pre-allocated huge pages of the default size. > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 0435bee2e172..1bce5f20e6ca 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -34,6 +34,7 @@ > #include <linux/gfp.h> > #include <linux/kcore.h> > #include <linux/bootmem_info.h> > +#include <linux/hugetlb.h> > > #include <asm/processor.h> > #include <asm/bios_ebda.h> > @@ -1557,7 +1558,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > { > int err; > > - if (end - start < PAGES_PER_SECTION * sizeof(struct page)) > + if (is_hugetlb_free_vmemmap_enabled() || > + end - start < PAGES_PER_SECTION * sizeof(struct page)) > err = vmemmap_populate_basepages(start, end, node, NULL); > else if (boot_cpu_has(X86_FEATURE_PSE)) > err = vmemmap_populate_hugepages(start, end, node, altmap); > @@ -1585,6 +1587,8 @@ void register_page_bootmem_memmap(unsigned long section_nr, > pmd_t *pmd; > unsigned int nr_pmd_pages; > struct page *page; > + bool base_mapping = !boot_cpu_has(X86_FEATURE_PSE) || > + is_hugetlb_free_vmemmap_enabled(); > > for (; addr < end; addr = next) { > pte_t *pte = NULL; > @@ -1610,7 +1614,7 @@ void register_page_bootmem_memmap(unsigned long section_nr, > } > get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); > > - if (!boot_cpu_has(X86_FEATURE_PSE)) { > + if (base_mapping) { > next = (addr + PAGE_SIZE) & PAGE_MASK; > pmd = pmd_offset(pud, addr); > if (pmd_none(*pmd)) > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index ebca2ef02212..7f47f0eeca3b 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -770,6 +770,20 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, > } > #endif > > +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP > +extern bool hugetlb_free_vmemmap_enabled; > + > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > +{ > + return hugetlb_free_vmemmap_enabled; > +} > +#else > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > +{ > + return false; > +} > +#endif > + > #else /* CONFIG_HUGETLB_PAGE */ > struct hstate {}; > > @@ -923,6 +937,11 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr > pte_t *ptep, pte_t pte, unsigned long sz) > { > } > + > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > +{ > + return false; > +} > #endif /* CONFIG_HUGETLB_PAGE */ > > static inline spinlock_t *huge_pte_lock(struct hstate *h, > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > index 02201c2e3dfa..64ad929cac61 100644 > --- a/mm/hugetlb_vmemmap.c > +++ b/mm/hugetlb_vmemmap.c > @@ -180,6 +180,22 @@ > #define RESERVE_VMEMMAP_NR 2U > #define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) > > +bool hugetlb_free_vmemmap_enabled; > + > +static int __init early_hugetlb_free_vmemmap_param(char *buf) > +{ > + if (!buf) > + return -EINVAL; > + > + if (!strcmp(buf, "on")) > + hugetlb_free_vmemmap_enabled = true; > + else if (strcmp(buf, "off")) > + return -EINVAL; > + > + return 0; > +} > +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); > + > static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) > { > return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT; > -- > 2.11.0 >
On Wed, Dec 16, 2020 at 10:40 PM Oscar Salvador <osalvador@suse.de> wrote: > > On Sun, Dec 13, 2020 at 11:45:31PM +0800, Muchun Song wrote: > > Add a kernel parameter hugetlb_free_vmemmap to disable the feature of > > freeing unused vmemmap pages associated with each hugetlb page on boot. > I guess this should read "to enable the feature"? > AFAICS, it is disabled by default. > > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > > Reviewed-by: Oscar Salvador <osalvador@suse.de> Thanks Oscar. > > > --- > > Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ > > Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ > > arch/x86/mm/init_64.c | 8 ++++++-- > > include/linux/hugetlb.h | 19 +++++++++++++++++++ > > mm/hugetlb_vmemmap.c | 16 ++++++++++++++++ > > 5 files changed, 53 insertions(+), 2 deletions(-) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > index 3ae25630a223..9e6854f21d55 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -1551,6 +1551,15 @@ > > Documentation/admin-guide/mm/hugetlbpage.rst. > > Format: size[KMG] > > > > + hugetlb_free_vmemmap= > > + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, > > + this controls freeing unused vmemmap pages associated > > + with each HugeTLB page. > > + Format: { on | off (default) } > > + > > + on: enable the feature > > + off: disable the feature > > + > > hung_task_panic= > > [KNL] Should the hung task detector generate panics. > > Format: 0 | 1 > > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst > > index f7b1c7462991..3a23c2377acc 100644 > > --- a/Documentation/admin-guide/mm/hugetlbpage.rst > > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst > > @@ -145,6 +145,9 @@ default_hugepagesz > > > > will all result in 256 2M huge pages being allocated. Valid default > > huge page size is architecture dependent. > > +hugetlb_free_vmemmap > > + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing > > + unused vmemmap pages associated with each HugeTLB page. > > > > When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` > > indicates the current number of pre-allocated huge pages of the default size. > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > > index 0435bee2e172..1bce5f20e6ca 100644 > > --- a/arch/x86/mm/init_64.c > > +++ b/arch/x86/mm/init_64.c > > @@ -34,6 +34,7 @@ > > #include <linux/gfp.h> > > #include <linux/kcore.h> > > #include <linux/bootmem_info.h> > > +#include <linux/hugetlb.h> > > > > #include <asm/processor.h> > > #include <asm/bios_ebda.h> > > @@ -1557,7 +1558,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > > { > > int err; > > > > - if (end - start < PAGES_PER_SECTION * sizeof(struct page)) > > + if (is_hugetlb_free_vmemmap_enabled() || > > + end - start < PAGES_PER_SECTION * sizeof(struct page)) > > err = vmemmap_populate_basepages(start, end, node, NULL); > > else if (boot_cpu_has(X86_FEATURE_PSE)) > > err = vmemmap_populate_hugepages(start, end, node, altmap); > > @@ -1585,6 +1587,8 @@ void register_page_bootmem_memmap(unsigned long section_nr, > > pmd_t *pmd; > > unsigned int nr_pmd_pages; > > struct page *page; > > + bool base_mapping = !boot_cpu_has(X86_FEATURE_PSE) || > > + is_hugetlb_free_vmemmap_enabled(); > > > > for (; addr < end; addr = next) { > > pte_t *pte = NULL; > > @@ -1610,7 +1614,7 @@ void register_page_bootmem_memmap(unsigned long section_nr, > > } > > get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); > > > > - if (!boot_cpu_has(X86_FEATURE_PSE)) { > > + if (base_mapping) { > > next = (addr + PAGE_SIZE) & PAGE_MASK; > > pmd = pmd_offset(pud, addr); > > if (pmd_none(*pmd)) > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > > index ebca2ef02212..7f47f0eeca3b 100644 > > --- a/include/linux/hugetlb.h > > +++ b/include/linux/hugetlb.h > > @@ -770,6 +770,20 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, > > } > > #endif > > > > +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP > > +extern bool hugetlb_free_vmemmap_enabled; > > + > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > +{ > > + return hugetlb_free_vmemmap_enabled; > > +} > > +#else > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > +{ > > + return false; > > +} > > +#endif > > + > > #else /* CONFIG_HUGETLB_PAGE */ > > struct hstate {}; > > > > @@ -923,6 +937,11 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr > > pte_t *ptep, pte_t pte, unsigned long sz) > > { > > } > > + > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > +{ > > + return false; > > +} > > #endif /* CONFIG_HUGETLB_PAGE */ > > > > static inline spinlock_t *huge_pte_lock(struct hstate *h, > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > > index 02201c2e3dfa..64ad929cac61 100644 > > --- a/mm/hugetlb_vmemmap.c > > +++ b/mm/hugetlb_vmemmap.c > > @@ -180,6 +180,22 @@ > > #define RESERVE_VMEMMAP_NR 2U > > #define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) > > > > +bool hugetlb_free_vmemmap_enabled; > > + > > +static int __init early_hugetlb_free_vmemmap_param(char *buf) > > +{ > > + if (!buf) > > + return -EINVAL; > > + > > + if (!strcmp(buf, "on")) > > + hugetlb_free_vmemmap_enabled = true; > > + else if (strcmp(buf, "off")) > > + return -EINVAL; > > + > > + return 0; > > +} > > +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); > > + > > static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) > > { > > return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT; > > -- > > 2.11.0 > > > > -- > Oscar Salvador > SUSE L3
On Thu, Dec 17, 2020 at 12:04:11AM +0800, Muchun Song wrote: > On Wed, Dec 16, 2020 at 10:40 PM Oscar Salvador <osalvador@suse.de> wrote: > > > > On Sun, Dec 13, 2020 at 11:45:31PM +0800, Muchun Song wrote: > > > Add a kernel parameter hugetlb_free_vmemmap to disable the feature of > > > freeing unused vmemmap pages associated with each hugetlb page on boot. > > I guess this should read "to enable the feature"? > > AFAICS, it is disabled by default. It still would be great to have an answer for that. Thanks > > > Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ > > > Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ > > > arch/x86/mm/init_64.c | 8 ++++++-- > > > include/linux/hugetlb.h | 19 +++++++++++++++++++ > > > mm/hugetlb_vmemmap.c | 16 ++++++++++++++++ > > > 5 files changed, 53 insertions(+), 2 deletions(-) > > > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > > index 3ae25630a223..9e6854f21d55 100644 > > > --- a/Documentation/admin-guide/kernel-parameters.txt > > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > > @@ -1551,6 +1551,15 @@ > > > Documentation/admin-guide/mm/hugetlbpage.rst. > > > Format: size[KMG] > > > > > > + hugetlb_free_vmemmap= > > > + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, > > > + this controls freeing unused vmemmap pages associated > > > + with each HugeTLB page. > > > + Format: { on | off (default) } > > > + > > > + on: enable the feature > > > + off: disable the feature > > > + > > > hung_task_panic= > > > [KNL] Should the hung task detector generate panics. > > > Format: 0 | 1 > > > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst > > > index f7b1c7462991..3a23c2377acc 100644 > > > --- a/Documentation/admin-guide/mm/hugetlbpage.rst > > > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst > > > @@ -145,6 +145,9 @@ default_hugepagesz > > > > > > will all result in 256 2M huge pages being allocated. Valid default > > > huge page size is architecture dependent. > > > +hugetlb_free_vmemmap > > > + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing > > > + unused vmemmap pages associated with each HugeTLB page. > > > > > > When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` > > > indicates the current number of pre-allocated huge pages of the default size. > > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > > > index 0435bee2e172..1bce5f20e6ca 100644 > > > --- a/arch/x86/mm/init_64.c > > > +++ b/arch/x86/mm/init_64.c > > > @@ -34,6 +34,7 @@ > > > #include <linux/gfp.h> > > > #include <linux/kcore.h> > > > #include <linux/bootmem_info.h> > > > +#include <linux/hugetlb.h> > > > > > > #include <asm/processor.h> > > > #include <asm/bios_ebda.h> > > > @@ -1557,7 +1558,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > > > { > > > int err; > > > > > > - if (end - start < PAGES_PER_SECTION * sizeof(struct page)) > > > + if (is_hugetlb_free_vmemmap_enabled() || > > > + end - start < PAGES_PER_SECTION * sizeof(struct page)) > > > err = vmemmap_populate_basepages(start, end, node, NULL); > > > else if (boot_cpu_has(X86_FEATURE_PSE)) > > > err = vmemmap_populate_hugepages(start, end, node, altmap); > > > @@ -1585,6 +1587,8 @@ void register_page_bootmem_memmap(unsigned long section_nr, > > > pmd_t *pmd; > > > unsigned int nr_pmd_pages; > > > struct page *page; > > > + bool base_mapping = !boot_cpu_has(X86_FEATURE_PSE) || > > > + is_hugetlb_free_vmemmap_enabled(); > > > > > > for (; addr < end; addr = next) { > > > pte_t *pte = NULL; > > > @@ -1610,7 +1614,7 @@ void register_page_bootmem_memmap(unsigned long section_nr, > > > } > > > get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); > > > > > > - if (!boot_cpu_has(X86_FEATURE_PSE)) { > > > + if (base_mapping) { > > > next = (addr + PAGE_SIZE) & PAGE_MASK; > > > pmd = pmd_offset(pud, addr); > > > if (pmd_none(*pmd)) > > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > > > index ebca2ef02212..7f47f0eeca3b 100644 > > > --- a/include/linux/hugetlb.h > > > +++ b/include/linux/hugetlb.h > > > @@ -770,6 +770,20 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, > > > } > > > #endif > > > > > > +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP > > > +extern bool hugetlb_free_vmemmap_enabled; > > > + > > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > > +{ > > > + return hugetlb_free_vmemmap_enabled; > > > +} > > > +#else > > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > > +{ > > > + return false; > > > +} > > > +#endif > > > + > > > #else /* CONFIG_HUGETLB_PAGE */ > > > struct hstate {}; > > > > > > @@ -923,6 +937,11 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr > > > pte_t *ptep, pte_t pte, unsigned long sz) > > > { > > > } > > > + > > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > > +{ > > > + return false; > > > +} > > > #endif /* CONFIG_HUGETLB_PAGE */ > > > > > > static inline spinlock_t *huge_pte_lock(struct hstate *h, > > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > > > index 02201c2e3dfa..64ad929cac61 100644 > > > --- a/mm/hugetlb_vmemmap.c > > > +++ b/mm/hugetlb_vmemmap.c > > > @@ -180,6 +180,22 @@ > > > #define RESERVE_VMEMMAP_NR 2U > > > #define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) > > > > > > +bool hugetlb_free_vmemmap_enabled; > > > + > > > +static int __init early_hugetlb_free_vmemmap_param(char *buf) > > > +{ > > > + if (!buf) > > > + return -EINVAL; > > > + > > > + if (!strcmp(buf, "on")) > > > + hugetlb_free_vmemmap_enabled = true; > > > + else if (strcmp(buf, "off")) > > > + return -EINVAL; > > > + > > > + return 0; > > > +} > > > +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); > > > + > > > static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) > > > { > > > return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT; > > > -- > > > 2.11.0 > > > > > > > -- > > Oscar Salvador > > SUSE L3 > > > > -- > Yours, > Muchun
On Thu, Dec 17, 2020 at 6:10 AM Oscar Salvador <osalvador@suse.de> wrote: > > On Thu, Dec 17, 2020 at 12:04:11AM +0800, Muchun Song wrote: > > On Wed, Dec 16, 2020 at 10:40 PM Oscar Salvador <osalvador@suse.de> wrote: > > > > > > On Sun, Dec 13, 2020 at 11:45:31PM +0800, Muchun Song wrote: > > > > Add a kernel parameter hugetlb_free_vmemmap to disable the feature of > > > > freeing unused vmemmap pages associated with each hugetlb page on boot. > > > I guess this should read "to enable the feature"? > > > AFAICS, it is disabled by default. Hi Oscar, Yeah, you are right. It is disabled by default. I forget to update the commit log. Thanks a lot for pointing this out. > > It still would be great to have an answer for that. > > Thanks > > > > > > Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ > > > > Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ > > > > arch/x86/mm/init_64.c | 8 ++++++-- > > > > include/linux/hugetlb.h | 19 +++++++++++++++++++ > > > > mm/hugetlb_vmemmap.c | 16 ++++++++++++++++ > > > > 5 files changed, 53 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > > > index 3ae25630a223..9e6854f21d55 100644 > > > > --- a/Documentation/admin-guide/kernel-parameters.txt > > > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > > > @@ -1551,6 +1551,15 @@ > > > > Documentation/admin-guide/mm/hugetlbpage.rst. > > > > Format: size[KMG] > > > > > > > > + hugetlb_free_vmemmap= > > > > + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, > > > > + this controls freeing unused vmemmap pages associated > > > > + with each HugeTLB page. > > > > + Format: { on | off (default) } > > > > + > > > > + on: enable the feature > > > > + off: disable the feature > > > > + > > > > hung_task_panic= > > > > [KNL] Should the hung task detector generate panics. > > > > Format: 0 | 1 > > > > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst > > > > index f7b1c7462991..3a23c2377acc 100644 > > > > --- a/Documentation/admin-guide/mm/hugetlbpage.rst > > > > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst > > > > @@ -145,6 +145,9 @@ default_hugepagesz > > > > > > > > will all result in 256 2M huge pages being allocated. Valid default > > > > huge page size is architecture dependent. > > > > +hugetlb_free_vmemmap > > > > + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing > > > > + unused vmemmap pages associated with each HugeTLB page. > > > > > > > > When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` > > > > indicates the current number of pre-allocated huge pages of the default size. > > > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > > > > index 0435bee2e172..1bce5f20e6ca 100644 > > > > --- a/arch/x86/mm/init_64.c > > > > +++ b/arch/x86/mm/init_64.c > > > > @@ -34,6 +34,7 @@ > > > > #include <linux/gfp.h> > > > > #include <linux/kcore.h> > > > > #include <linux/bootmem_info.h> > > > > +#include <linux/hugetlb.h> > > > > > > > > #include <asm/processor.h> > > > > #include <asm/bios_ebda.h> > > > > @@ -1557,7 +1558,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > > > > { > > > > int err; > > > > > > > > - if (end - start < PAGES_PER_SECTION * sizeof(struct page)) > > > > + if (is_hugetlb_free_vmemmap_enabled() || > > > > + end - start < PAGES_PER_SECTION * sizeof(struct page)) > > > > err = vmemmap_populate_basepages(start, end, node, NULL); > > > > else if (boot_cpu_has(X86_FEATURE_PSE)) > > > > err = vmemmap_populate_hugepages(start, end, node, altmap); > > > > @@ -1585,6 +1587,8 @@ void register_page_bootmem_memmap(unsigned long section_nr, > > > > pmd_t *pmd; > > > > unsigned int nr_pmd_pages; > > > > struct page *page; > > > > + bool base_mapping = !boot_cpu_has(X86_FEATURE_PSE) || > > > > + is_hugetlb_free_vmemmap_enabled(); > > > > > > > > for (; addr < end; addr = next) { > > > > pte_t *pte = NULL; > > > > @@ -1610,7 +1614,7 @@ void register_page_bootmem_memmap(unsigned long section_nr, > > > > } > > > > get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); > > > > > > > > - if (!boot_cpu_has(X86_FEATURE_PSE)) { > > > > + if (base_mapping) { > > > > next = (addr + PAGE_SIZE) & PAGE_MASK; > > > > pmd = pmd_offset(pud, addr); > > > > if (pmd_none(*pmd)) > > > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > > > > index ebca2ef02212..7f47f0eeca3b 100644 > > > > --- a/include/linux/hugetlb.h > > > > +++ b/include/linux/hugetlb.h > > > > @@ -770,6 +770,20 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, > > > > } > > > > #endif > > > > > > > > +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP > > > > +extern bool hugetlb_free_vmemmap_enabled; > > > > + > > > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > > > +{ > > > > + return hugetlb_free_vmemmap_enabled; > > > > +} > > > > +#else > > > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > > > +{ > > > > + return false; > > > > +} > > > > +#endif > > > > + > > > > #else /* CONFIG_HUGETLB_PAGE */ > > > > struct hstate {}; > > > > > > > > @@ -923,6 +937,11 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr > > > > pte_t *ptep, pte_t pte, unsigned long sz) > > > > { > > > > } > > > > + > > > > +static inline bool is_hugetlb_free_vmemmap_enabled(void) > > > > +{ > > > > + return false; > > > > +} > > > > #endif /* CONFIG_HUGETLB_PAGE */ > > > > > > > > static inline spinlock_t *huge_pte_lock(struct hstate *h, > > > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > > > > index 02201c2e3dfa..64ad929cac61 100644 > > > > --- a/mm/hugetlb_vmemmap.c > > > > +++ b/mm/hugetlb_vmemmap.c > > > > @@ -180,6 +180,22 @@ > > > > #define RESERVE_VMEMMAP_NR 2U > > > > #define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) > > > > > > > > +bool hugetlb_free_vmemmap_enabled; > > > > + > > > > +static int __init early_hugetlb_free_vmemmap_param(char *buf) > > > > +{ > > > > + if (!buf) > > > > + return -EINVAL; > > > > + > > > > + if (!strcmp(buf, "on")) > > > > + hugetlb_free_vmemmap_enabled = true; > > > > + else if (strcmp(buf, "off")) > > > > + return -EINVAL; > > > > + > > > > + return 0; > > > > +} > > > > +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); > > > > + > > > > static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) > > > > { > > > > return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT; > > > > -- > > > > 2.11.0 > > > > > > > > > > -- > > > Oscar Salvador > > > SUSE L3 > > > > > > > > -- > > Yours, > > Muchun > > -- > Oscar Salvador > SUSE L3
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3ae25630a223..9e6854f21d55 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1551,6 +1551,15 @@ Documentation/admin-guide/mm/hugetlbpage.rst. Format: size[KMG] + hugetlb_free_vmemmap= + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, + this controls freeing unused vmemmap pages associated + with each HugeTLB page. + Format: { on | off (default) } + + on: enable the feature + off: disable the feature + hung_task_panic= [KNL] Should the hung task detector generate panics. Format: 0 | 1 diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst index f7b1c7462991..3a23c2377acc 100644 --- a/Documentation/admin-guide/mm/hugetlbpage.rst +++ b/Documentation/admin-guide/mm/hugetlbpage.rst @@ -145,6 +145,9 @@ default_hugepagesz will all result in 256 2M huge pages being allocated. Valid default huge page size is architecture dependent. +hugetlb_free_vmemmap + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing + unused vmemmap pages associated with each HugeTLB page. When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` indicates the current number of pre-allocated huge pages of the default size. diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 0435bee2e172..1bce5f20e6ca 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -34,6 +34,7 @@ #include <linux/gfp.h> #include <linux/kcore.h> #include <linux/bootmem_info.h> +#include <linux/hugetlb.h> #include <asm/processor.h> #include <asm/bios_ebda.h> @@ -1557,7 +1558,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, { int err; - if (end - start < PAGES_PER_SECTION * sizeof(struct page)) + if (is_hugetlb_free_vmemmap_enabled() || + end - start < PAGES_PER_SECTION * sizeof(struct page)) err = vmemmap_populate_basepages(start, end, node, NULL); else if (boot_cpu_has(X86_FEATURE_PSE)) err = vmemmap_populate_hugepages(start, end, node, altmap); @@ -1585,6 +1587,8 @@ void register_page_bootmem_memmap(unsigned long section_nr, pmd_t *pmd; unsigned int nr_pmd_pages; struct page *page; + bool base_mapping = !boot_cpu_has(X86_FEATURE_PSE) || + is_hugetlb_free_vmemmap_enabled(); for (; addr < end; addr = next) { pte_t *pte = NULL; @@ -1610,7 +1614,7 @@ void register_page_bootmem_memmap(unsigned long section_nr, } get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); - if (!boot_cpu_has(X86_FEATURE_PSE)) { + if (base_mapping) { next = (addr + PAGE_SIZE) & PAGE_MASK; pmd = pmd_offset(pud, addr); if (pmd_none(*pmd)) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index ebca2ef02212..7f47f0eeca3b 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -770,6 +770,20 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, } #endif +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP +extern bool hugetlb_free_vmemmap_enabled; + +static inline bool is_hugetlb_free_vmemmap_enabled(void) +{ + return hugetlb_free_vmemmap_enabled; +} +#else +static inline bool is_hugetlb_free_vmemmap_enabled(void) +{ + return false; +} +#endif + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; @@ -923,6 +937,11 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr pte_t *ptep, pte_t pte, unsigned long sz) { } + +static inline bool is_hugetlb_free_vmemmap_enabled(void) +{ + return false; +} #endif /* CONFIG_HUGETLB_PAGE */ static inline spinlock_t *huge_pte_lock(struct hstate *h, diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 02201c2e3dfa..64ad929cac61 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -180,6 +180,22 @@ #define RESERVE_VMEMMAP_NR 2U #define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) +bool hugetlb_free_vmemmap_enabled; + +static int __init early_hugetlb_free_vmemmap_param(char *buf) +{ + if (!buf) + return -EINVAL; + + if (!strcmp(buf, "on")) + hugetlb_free_vmemmap_enabled = true; + else if (strcmp(buf, "off")) + return -EINVAL; + + return 0; +} +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); + static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) { return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT;
Add a kernel parameter hugetlb_free_vmemmap to disable the feature of freeing unused vmemmap pages associated with each hugetlb page on boot. Signed-off-by: Muchun Song <songmuchun@bytedance.com> --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ arch/x86/mm/init_64.c | 8 ++++++-- include/linux/hugetlb.h | 19 +++++++++++++++++++ mm/hugetlb_vmemmap.c | 16 ++++++++++++++++ 5 files changed, 53 insertions(+), 2 deletions(-)