Now that batching of hugetlb vmemmap optimization processing is possible,
batch the freeing of vmemmap pages. When freeing vmemmap pages for a
hugetlb page, we add them to a list that is freed after the entire batch
has been processed.
This enhances the ability to return contiguous ranges of memory to the
low level allocators.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
---
mm/hugetlb_vmemmap.c | 56 ++++++++++++++++++++++++++++++++------------
1 file changed, 41 insertions(+), 15 deletions(-)
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index d5e6b6c76dce..e390170c0887 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -305,11 +305,14 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
* @end: end address of the vmemmap virtual address range that we want to
* remap.
* @reuse: reuse address.
+ * @bulk_pages: list to deposit vmemmap pages to be freed in bulk operations
+ * or NULL in non-bulk case;
*
* Return: %0 on success, negative error code otherwise.
*/
static int vmemmap_remap_free(unsigned long start, unsigned long end,
- unsigned long reuse)
+ unsigned long reuse,
+ struct list_head *bulk_pages)
{
int ret;
LIST_HEAD(vmemmap_pages);
@@ -372,7 +375,14 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end,
}
mmap_read_unlock(&init_mm);
- free_vmemmap_page_list(&vmemmap_pages);
+ /*
+ * if performing bulk operation, do not free pages here.
+ * rather add them to the bulk list
+ */
+ if (!bulk_pages)
+ free_vmemmap_page_list(&vmemmap_pages);
+ else
+ list_splice(&vmemmap_pages, bulk_pages);
return ret;
}
@@ -546,17 +556,9 @@ static bool vmemmap_should_optimize(const struct hstate *h, const struct page *h
return true;
}
-/**
- * hugetlb_vmemmap_optimize - optimize @head page's vmemmap pages.
- * @h: struct hstate.
- * @head: the head page whose vmemmap pages will be optimized.
- *
- * This function only tries to optimize @head's vmemmap pages and does not
- * guarantee that the optimization will succeed after it returns. The caller
- * can use HPageVmemmapOptimized(@head) to detect if @head's vmemmap pages
- * have been optimized.
- */
-void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
+static void __hugetlb_vmemmap_optimize(const struct hstate *h,
+ struct page *head,
+ struct list_head *bulk_pages)
{
unsigned long vmemmap_start = (unsigned long)head, vmemmap_end;
unsigned long vmemmap_reuse;
@@ -575,18 +577,42 @@ void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
* to the page which @vmemmap_reuse is mapped to, then free the pages
* which the range [@vmemmap_start, @vmemmap_end] is mapped to.
*/
- if (vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse))
+ if (vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse, bulk_pages))
static_branch_dec(&hugetlb_optimize_vmemmap_key);
else
SetHPageVmemmapOptimized(head);
}
+/**
+ * hugetlb_vmemmap_optimize - optimize @head page's vmemmap pages.
+ * @h: struct hstate.
+ * @head: the head page whose vmemmap pages will be optimized.
+ *
+ * This function only tries to optimize @head's vmemmap pages and does not
+ * guarantee that the optimization will succeed after it returns. The caller
+ * can use HPageVmemmapOptimized(@head) to detect if @head's vmemmap pages
+ * have been optimized.
+ */
+void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
+{
+ __hugetlb_vmemmap_optimize(h, head, NULL);
+}
+
+void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
+ struct list_head *bulk_pages)
+{
+ __hugetlb_vmemmap_optimize(h, head, bulk_pages);
+}
+
void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list)
{
struct folio *folio;
+ LIST_HEAD(vmemmap_pages);
list_for_each_entry(folio, folio_list, lru)
- hugetlb_vmemmap_optimize(h, &folio->page);
+ hugetlb_vmemmap_optimize_bulk(h, &folio->page, &vmemmap_pages);
+
+ free_vmemmap_page_list(&vmemmap_pages);
}
static struct ctl_table hugetlb_vmemmap_sysctls[] = {
--
2.41.0
On 2023/8/26 03:04, Mike Kravetz wrote:
> Now that batching of hugetlb vmemmap optimization processing is possible,
> batch the freeing of vmemmap pages. When freeing vmemmap pages for a
> hugetlb page, we add them to a list that is freed after the entire batch
> has been processed.
>
> This enhances the ability to return contiguous ranges of memory to the
> low level allocators.
>
> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
> ---
> mm/hugetlb_vmemmap.c | 56 ++++++++++++++++++++++++++++++++------------
> 1 file changed, 41 insertions(+), 15 deletions(-)
>
> diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
> index d5e6b6c76dce..e390170c0887 100644
> --- a/mm/hugetlb_vmemmap.c
> +++ b/mm/hugetlb_vmemmap.c
> @@ -305,11 +305,14 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
> * @end: end address of the vmemmap virtual address range that we want to
> * remap.
> * @reuse: reuse address.
> + * @bulk_pages: list to deposit vmemmap pages to be freed in bulk operations
> + * or NULL in non-bulk case;
I'd like to rename bulk_pages to vmemmap_pages. Always add the vmemmap
pages to this list and let the caller (hugetlb_vmemmap_optimize and
hugetlb_vmemmap_optimize_folios) to help us to free them. It will be
clear to me.
> *
> * Return: %0 on success, negative error code otherwise.
> */
> static int vmemmap_remap_free(unsigned long start, unsigned long end,
> - unsigned long reuse)
> + unsigned long reuse,
> + struct list_head *bulk_pages)
> {
> int ret;
> LIST_HEAD(vmemmap_pages);
> @@ -372,7 +375,14 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end,
> }
> mmap_read_unlock(&init_mm);
>
> - free_vmemmap_page_list(&vmemmap_pages);
> + /*
> + * if performing bulk operation, do not free pages here.
> + * rather add them to the bulk list
> + */
> + if (!bulk_pages)
> + free_vmemmap_page_list(&vmemmap_pages);
> + else
> + list_splice(&vmemmap_pages, bulk_pages);
Here, always add vmemmap_pages to the list.
>
> return ret;
> }
> @@ -546,17 +556,9 @@ static bool vmemmap_should_optimize(const struct hstate *h, const struct page *h
> return true;
> }
>
> -/**
> - * hugetlb_vmemmap_optimize - optimize @head page's vmemmap pages.
> - * @h: struct hstate.
> - * @head: the head page whose vmemmap pages will be optimized.
> - *
> - * This function only tries to optimize @head's vmemmap pages and does not
> - * guarantee that the optimization will succeed after it returns. The caller
> - * can use HPageVmemmapOptimized(@head) to detect if @head's vmemmap pages
> - * have been optimized.
> - */
> -void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
> +static void __hugetlb_vmemmap_optimize(const struct hstate *h,
> + struct page *head,
> + struct list_head *bulk_pages)
Also struct list_head *vmemmap_pages.
> {
> unsigned long vmemmap_start = (unsigned long)head, vmemmap_end;
> unsigned long vmemmap_reuse;
> @@ -575,18 +577,42 @@ void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
> * to the page which @vmemmap_reuse is mapped to, then free the pages
> * which the range [@vmemmap_start, @vmemmap_end] is mapped to.
> */
> - if (vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse))
> + if (vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse, bulk_pages))
> static_branch_dec(&hugetlb_optimize_vmemmap_key);
> else
> SetHPageVmemmapOptimized(head);
> }
>
> +/**
> + * hugetlb_vmemmap_optimize - optimize @head page's vmemmap pages.
> + * @h: struct hstate.
> + * @head: the head page whose vmemmap pages will be optimized.
> + *
> + * This function only tries to optimize @head's vmemmap pages and does not
> + * guarantee that the optimization will succeed after it returns. The caller
> + * can use HPageVmemmapOptimized(@head) to detect if @head's vmemmap pages
> + * have been optimized.
> + */
> +void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
> +{
> + __hugetlb_vmemmap_optimize(h, head, NULL);
Use free_vmemmap_page_list to free vmemmap pages here.
> +}
> +
> +void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
> + struct list_head *bulk_pages)
> +{
> + __hugetlb_vmemmap_optimize(h, head, bulk_pages);
> +}
> +
> void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list)
> {
> struct folio *folio;
> + LIST_HEAD(vmemmap_pages);
>
> list_for_each_entry(folio, folio_list, lru)
> - hugetlb_vmemmap_optimize(h, &folio->page);
> + hugetlb_vmemmap_optimize_bulk(h, &folio->page, &vmemmap_pages);
Directly use __hugetlb_vmemmap_optimize and delete
hugetlb_vmemmap_optimize_bulk.
In the future, we could rename hugetlb_vmemmap_optimize to
hugetlb_vmemmap_optimize_folio,
then, both function names are more consistent. E.g.
1) hugetlb_vmemmap_optimize_folio(): used to free one folio's vmemmap
pages.
2) hugetlb_vmemmap_optimize_folios(): used to free multiple folio's
vmemmap pages.
Thanks.
> +
> + free_vmemmap_page_list(&vmemmap_pages);
> }
>
> static struct ctl_table hugetlb_vmemmap_sysctls[] = {
On 08/30/23 15:20, Muchun Song wrote:
>
>
> On 2023/8/26 03:04, Mike Kravetz wrote:
> > Now that batching of hugetlb vmemmap optimization processing is possible,
> > batch the freeing of vmemmap pages. When freeing vmemmap pages for a
> > hugetlb page, we add them to a list that is freed after the entire batch
> > has been processed.
> >
> > This enhances the ability to return contiguous ranges of memory to the
> > low level allocators.
> >
> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
> > ---
> > mm/hugetlb_vmemmap.c | 56 ++++++++++++++++++++++++++++++++------------
> > 1 file changed, 41 insertions(+), 15 deletions(-)
> >
> > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
> > index d5e6b6c76dce..e390170c0887 100644
> > --- a/mm/hugetlb_vmemmap.c
> > +++ b/mm/hugetlb_vmemmap.c
> > @@ -305,11 +305,14 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
> > * @end: end address of the vmemmap virtual address range that we want to
> > * remap.
> > * @reuse: reuse address.
> > + * @bulk_pages: list to deposit vmemmap pages to be freed in bulk operations
> > + * or NULL in non-bulk case;
>
> I'd like to rename bulk_pages to vmemmap_pages. Always add the vmemmap
> pages to this list and let the caller (hugetlb_vmemmap_optimize and
> hugetlb_vmemmap_optimize_folios) to help us to free them. It will be
> clear to me.
Makes sense.
I will update all these in next version based on your suggestions.
Thank you,
--
Mike Kravetz
>
> > *
> > * Return: %0 on success, negative error code otherwise.
> > */
> > static int vmemmap_remap_free(unsigned long start, unsigned long end,
> > - unsigned long reuse)
> > + unsigned long reuse,
> > + struct list_head *bulk_pages)
> > {
> > int ret;
> > LIST_HEAD(vmemmap_pages);
> > @@ -372,7 +375,14 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end,
> > }
> > mmap_read_unlock(&init_mm);
> > - free_vmemmap_page_list(&vmemmap_pages);
> > + /*
> > + * if performing bulk operation, do not free pages here.
> > + * rather add them to the bulk list
> > + */
> > + if (!bulk_pages)
> > + free_vmemmap_page_list(&vmemmap_pages);
> > + else
> > + list_splice(&vmemmap_pages, bulk_pages);
>
> Here, always add vmemmap_pages to the list.
>
> > return ret;
> > }
> > @@ -546,17 +556,9 @@ static bool vmemmap_should_optimize(const struct hstate *h, const struct page *h
> > return true;
> > }
> > -/**
> > - * hugetlb_vmemmap_optimize - optimize @head page's vmemmap pages.
> > - * @h: struct hstate.
> > - * @head: the head page whose vmemmap pages will be optimized.
> > - *
> > - * This function only tries to optimize @head's vmemmap pages and does not
> > - * guarantee that the optimization will succeed after it returns. The caller
> > - * can use HPageVmemmapOptimized(@head) to detect if @head's vmemmap pages
> > - * have been optimized.
> > - */
> > -void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
> > +static void __hugetlb_vmemmap_optimize(const struct hstate *h,
> > + struct page *head,
> > + struct list_head *bulk_pages)
>
> Also struct list_head *vmemmap_pages.
>
> > {
> > unsigned long vmemmap_start = (unsigned long)head, vmemmap_end;
> > unsigned long vmemmap_reuse;
> > @@ -575,18 +577,42 @@ void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
> > * to the page which @vmemmap_reuse is mapped to, then free the pages
> > * which the range [@vmemmap_start, @vmemmap_end] is mapped to.
> > */
> > - if (vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse))
> > + if (vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse, bulk_pages))
> > static_branch_dec(&hugetlb_optimize_vmemmap_key);
> > else
> > SetHPageVmemmapOptimized(head);
> > }
> > +/**
> > + * hugetlb_vmemmap_optimize - optimize @head page's vmemmap pages.
> > + * @h: struct hstate.
> > + * @head: the head page whose vmemmap pages will be optimized.
> > + *
> > + * This function only tries to optimize @head's vmemmap pages and does not
> > + * guarantee that the optimization will succeed after it returns. The caller
> > + * can use HPageVmemmapOptimized(@head) to detect if @head's vmemmap pages
> > + * have been optimized.
> > + */
> > +void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
> > +{
> > + __hugetlb_vmemmap_optimize(h, head, NULL);
>
> Use free_vmemmap_page_list to free vmemmap pages here.
>
> > +}
> > +
> > +void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
> > + struct list_head *bulk_pages)
> > +{
> > + __hugetlb_vmemmap_optimize(h, head, bulk_pages);
> > +}
> > +
> > void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list)
> > {
> > struct folio *folio;
> > + LIST_HEAD(vmemmap_pages);
> > list_for_each_entry(folio, folio_list, lru)
> > - hugetlb_vmemmap_optimize(h, &folio->page);
> > + hugetlb_vmemmap_optimize_bulk(h, &folio->page, &vmemmap_pages);
>
> Directly use __hugetlb_vmemmap_optimize and delete
> hugetlb_vmemmap_optimize_bulk.
> In the future, we could rename hugetlb_vmemmap_optimize to
> hugetlb_vmemmap_optimize_folio,
> then, both function names are more consistent. E.g.
>
> 1) hugetlb_vmemmap_optimize_folio(): used to free one folio's vmemmap
> pages.
> 2) hugetlb_vmemmap_optimize_folios(): used to free multiple folio's
> vmemmap pages.
>
> Thanks.
>
> > +
> > + free_vmemmap_page_list(&vmemmap_pages);
> > }
> > static struct ctl_table hugetlb_vmemmap_sysctls[] = {
>
Hi Mike,
kernel test robot noticed the following build warnings:
[auto build test WARNING on next-20230825]
[cannot apply to akpm-mm/mm-everything v6.5-rc7 v6.5-rc6 v6.5-rc5 linus/master v6.5-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Mike-Kravetz/hugetlb-clear-flags-in-tail-pages-that-will-be-freed-individually/20230826-030805
base: next-20230825
patch link: https://lore.kernel.org/r/20230825190436.55045-9-mike.kravetz%40oracle.com
patch subject: [PATCH 08/12] hugetlb: batch freeing of vmemmap pages
config: s390-randconfig-001-20230826 (https://download.01.org/0day-ci/archive/20230826/202308261129.hdlNvI3X-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce: (https://download.01.org/0day-ci/archive/20230826/202308261129.hdlNvI3X-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308261129.hdlNvI3X-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> mm/hugetlb_vmemmap.c:601:6: warning: no previous prototype for function 'hugetlb_vmemmap_optimize_bulk' [-Wmissing-prototypes]
601 | void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
| ^
mm/hugetlb_vmemmap.c:601:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
601 | void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
| ^
| static
1 warning generated.
vim +/hugetlb_vmemmap_optimize_bulk +601 mm/hugetlb_vmemmap.c
600
> 601 void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
602 struct list_head *bulk_pages)
603 {
604 __hugetlb_vmemmap_optimize(h, head, bulk_pages);
605 }
606
--
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