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authorMike Kravetz <mike.kravetz@oracle.com>2023-10-19 05:31:07 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-10-26 02:47:07 +0300
commit91f386bf0772c1976622bd0b119b78094603c3d0 (patch)
tree53e926ca6df835b33892c24184e2de5f2df836dd /mm/hugetlb_vmemmap.c
parentcfb8c75099dbf152db1b075eead5029c5a30ce51 (diff)
downloadlinux-91f386bf0772c1976622bd0b119b78094603c3d0.tar.xz
hugetlb: batch freeing of vmemmap pages
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. Link: https://lkml.kernel.org/r/20231019023113.345257-6-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <21cnbao@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Konrad Dybcio <konradybcio@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Usama Arif <usama.arif@bytedance.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb_vmemmap.c')
-rw-r--r--mm/hugetlb_vmemmap.c82
1 files changed, 56 insertions, 26 deletions
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 77f44b81ff01..4ac521e596db 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -251,7 +251,7 @@ static void vmemmap_remap_pte(pte_t *pte, unsigned long addr,
}
entry = mk_pte(walk->reuse_page, pgprot);
- list_add_tail(&page->lru, walk->vmemmap_pages);
+ list_add(&page->lru, walk->vmemmap_pages);
set_pte_at(&init_mm, addr, pte, entry);
}
@@ -306,18 +306,20 @@ 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.
+ * @vmemmap_pages: list to deposit vmemmap pages to be freed. It is callers
+ * responsibility to free pages.
*
* 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 *vmemmap_pages)
{
int ret;
- LIST_HEAD(vmemmap_pages);
struct vmemmap_remap_walk walk = {
.remap_pte = vmemmap_remap_pte,
.reuse_addr = reuse,
- .vmemmap_pages = &vmemmap_pages,
+ .vmemmap_pages = vmemmap_pages,
};
int nid = page_to_nid((struct page *)reuse);
gfp_t gfp_mask = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
@@ -334,7 +336,7 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end,
if (walk.reuse_page) {
copy_page(page_to_virt(walk.reuse_page),
(void *)walk.reuse_addr);
- list_add(&walk.reuse_page->lru, &vmemmap_pages);
+ list_add(&walk.reuse_page->lru, vmemmap_pages);
}
/*
@@ -365,15 +367,13 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end,
walk = (struct vmemmap_remap_walk) {
.remap_pte = vmemmap_restore_pte,
.reuse_addr = reuse,
- .vmemmap_pages = &vmemmap_pages,
+ .vmemmap_pages = vmemmap_pages,
};
vmemmap_remap_range(reuse, end, &walk);
}
mmap_read_unlock(&init_mm);
- free_vmemmap_page_list(&vmemmap_pages);
-
return ret;
}
@@ -389,7 +389,7 @@ static int alloc_vmemmap_page_list(unsigned long start, unsigned long end,
page = alloc_pages_node(nid, gfp_mask, 0);
if (!page)
goto out;
- list_add_tail(&page->lru, list);
+ list_add(&page->lru, list);
}
return 0;
@@ -577,24 +577,17 @@ 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 int __hugetlb_vmemmap_optimize(const struct hstate *h,
+ struct page *head,
+ struct list_head *vmemmap_pages)
{
+ int ret = 0;
unsigned long vmemmap_start = (unsigned long)head, vmemmap_end;
unsigned long vmemmap_reuse;
VM_WARN_ON_ONCE(!PageHuge(head));
if (!vmemmap_should_optimize(h, head))
- return;
+ return ret;
static_branch_inc(&hugetlb_optimize_vmemmap_key);
@@ -604,21 +597,58 @@ void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head)
/*
* Remap the vmemmap virtual address range [@vmemmap_start, @vmemmap_end)
- * to the page which @vmemmap_reuse is mapped to, then free the pages
- * which the range [@vmemmap_start, @vmemmap_end] is mapped to.
+ * to the page which @vmemmap_reuse is mapped to. Add pages previously
+ * mapping the range to vmemmap_pages list so that they can be freed by
+ * the caller.
*/
- if (vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse))
+ ret = vmemmap_remap_free(vmemmap_start, vmemmap_end, vmemmap_reuse, vmemmap_pages);
+ if (ret)
static_branch_dec(&hugetlb_optimize_vmemmap_key);
else
SetHPageVmemmapOptimized(head);
+
+ return ret;
+}
+
+/**
+ * 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)
+{
+ LIST_HEAD(vmemmap_pages);
+
+ __hugetlb_vmemmap_optimize(h, head, &vmemmap_pages);
+ free_vmemmap_page_list(&vmemmap_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) {
+ int ret = __hugetlb_vmemmap_optimize(h, &folio->page,
+ &vmemmap_pages);
+
+ /*
+ * Pages to be freed may have been accumulated. If we
+ * encounter an ENOMEM, free what we have and try again.
+ */
+ if (ret == -ENOMEM && !list_empty(&vmemmap_pages)) {
+ free_vmemmap_page_list(&vmemmap_pages);
+ INIT_LIST_HEAD(&vmemmap_pages);
+ __hugetlb_vmemmap_optimize(h, &folio->page, &vmemmap_pages);
+ }
+ }
- list_for_each_entry(folio, folio_list, lru)
- hugetlb_vmemmap_optimize(h, &folio->page);
+ free_vmemmap_page_list(&vmemmap_pages);
}
static struct ctl_table hugetlb_vmemmap_sysctls[] = {