From: Muchun Song <songmuchun@bytedance.com>
To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com,
dave.hansen@linux.intel.com, luto@kernel.org,
peterz@infradead.org, viro@zeniv.linux.org.uk,
akpm@linux-foundation.org, paulmck@kernel.org,
mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com,
rdunlap@infradead.org, oneukum@suse.com,
anshuman.khandual@arm.com, jroedel@suse.de,
almasrymina@google.com, rientjes@google.com, willy@infradead.org,
osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com,
david@redhat.com, naoya.horiguchi@nec.com,
joao.m.martins@oracle.com
Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org,
Muchun Song <songmuchun@bytedance.com>,
Miaohe Lin <linmiaohe@huawei.com>
Subject: [PATCH v15 6/8] mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate
Date: Mon, 8 Feb 2021 16:50:11 +0800 [thread overview]
Message-ID: <20210208085013.89436-7-songmuchun@bytedance.com> (raw)
In-Reply-To: <20210208085013.89436-1-songmuchun@bytedance.com>
All the infrastructure is ready, so we introduce nr_free_vmemmap_pages
field in the hstate to indicate how many vmemmap pages associated with
a HugeTLB page that can be freed to buddy allocator. And initialize it
in the hugetlb_vmemmap_init(). This patch is actual enablement of the
feature.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
---
include/linux/hugetlb.h | 3 +++
mm/hugetlb.c | 1 +
mm/hugetlb_vmemmap.c | 30 ++++++++++++++++++++++++++----
mm/hugetlb_vmemmap.h | 5 +++++
4 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index ad249e56ac49..775aea53669a 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -560,6 +560,9 @@ struct hstate {
unsigned int nr_huge_pages_node[MAX_NUMNODES];
unsigned int free_huge_pages_node[MAX_NUMNODES];
unsigned int surplus_huge_pages_node[MAX_NUMNODES];
+#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+ unsigned int nr_free_vmemmap_pages;
+#endif
#ifdef CONFIG_CGROUP_HUGETLB
/* cgroup control files */
struct cftype cgroup_files_dfl[7];
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 69dcbaa2e6db..89b500075d1f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3220,6 +3220,7 @@ void __init hugetlb_add_hstate(unsigned int order)
h->next_nid_to_free = first_memory_node;
snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
huge_page_size(h)/1024);
+ hugetlb_vmemmap_init(h);
parsed_hstate = h;
}
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 2fa6fff9f5dd..ac29753fb297 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -208,13 +208,10 @@ early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param);
/*
* How many vmemmap pages associated with a HugeTLB page that can be freed
* to the buddy allocator.
- *
- * Todo: Returns zero for now, which means the feature is disabled. We will
- * enable it once all the infrastructure is there.
*/
static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h)
{
- return 0;
+ return h->nr_free_vmemmap_pages;
}
static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h)
@@ -269,3 +266,28 @@ void free_huge_page_vmemmap(struct hstate *h, struct page *head)
*/
vmemmap_remap_free(vmemmap_addr, vmemmap_end, vmemmap_reuse);
}
+
+void __init hugetlb_vmemmap_init(struct hstate *h)
+{
+ unsigned int nr_pages = pages_per_huge_page(h);
+ unsigned int vmemmap_pages;
+
+ if (!hugetlb_free_vmemmap_enabled)
+ return;
+
+ vmemmap_pages = (nr_pages * sizeof(struct page)) >> PAGE_SHIFT;
+ /*
+ * The head page and the first tail page are not to be freed to buddy
+ * allocator, the other pages will map to the first tail page, so they
+ * can be freed.
+ *
+ * Could RESERVE_VMEMMAP_NR be greater than @vmemmap_pages? It is true
+ * on some architectures (e.g. aarch64). See Documentation/arm64/
+ * hugetlbpage.rst for more details.
+ */
+ if (likely(vmemmap_pages > RESERVE_VMEMMAP_NR))
+ h->nr_free_vmemmap_pages = vmemmap_pages - RESERVE_VMEMMAP_NR;
+
+ pr_info("can free %d vmemmap pages for %s\n", h->nr_free_vmemmap_pages,
+ h->name);
+}
diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h
index e5547d53b9f5..9bc35d328ddf 100644
--- a/mm/hugetlb_vmemmap.h
+++ b/mm/hugetlb_vmemmap.h
@@ -13,6 +13,7 @@
#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
int alloc_huge_page_vmemmap(struct hstate *h, struct page *head);
void free_huge_page_vmemmap(struct hstate *h, struct page *head);
+void hugetlb_vmemmap_init(struct hstate *h);
#else
static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head)
{
@@ -22,5 +23,9 @@ static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head)
static inline void free_huge_page_vmemmap(struct hstate *h, struct page *head)
{
}
+
+static inline void hugetlb_vmemmap_init(struct hstate *h)
+{
+}
#endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */
#endif /* _LINUX_HUGETLB_VMEMMAP_H */
--
2.11.0
next prev parent reply other threads:[~2021-02-08 8:53 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 8:50 [PATCH v15 0/8] Free some vmemmap pages of HugeTLB page Muchun Song
2021-02-08 8:50 ` [PATCH v15 1/8] mm: memory_hotplug: factor out bootmem core functions to bootmem_info.c Muchun Song
2021-02-08 8:50 ` [PATCH v15 2/8] mm: hugetlb: introduce a new config HUGETLB_PAGE_FREE_VMEMMAP Muchun Song
2021-02-08 8:50 ` [PATCH v15 3/8] mm: hugetlb: free the vmemmap pages associated with each HugeTLB page Muchun Song
2021-02-08 8:50 ` [PATCH v15 4/8] mm: hugetlb: alloc " Muchun Song
2021-02-11 18:05 ` Mike Kravetz
2021-02-12 14:15 ` David Hildenbrand
2021-02-12 15:32 ` Michal Hocko
2021-02-15 10:05 ` [External] " Muchun Song
2021-02-15 10:33 ` Michal Hocko
2021-02-15 11:51 ` Muchun Song
2021-02-15 12:00 ` Muchun Song
2021-02-15 12:18 ` Michal Hocko
2021-02-15 12:44 ` Muchun Song
2021-02-15 13:19 ` Michal Hocko
2021-02-15 15:36 ` Muchun Song
2021-02-15 16:27 ` Michal Hocko
2021-02-15 17:48 ` Muchun Song
2021-02-15 18:19 ` Muchun Song
2021-02-15 19:39 ` Michal Hocko
2021-02-16 4:34 ` Muchun Song
2021-02-16 8:15 ` Michal Hocko
2021-02-16 8:20 ` David Hildenbrand
2021-02-16 9:03 ` Muchun Song
2021-02-15 19:02 ` Michal Hocko
2021-02-16 8:13 ` David Hildenbrand
2021-02-16 8:21 ` Michal Hocko
2021-02-16 19:44 ` Mike Kravetz
2021-02-17 8:13 ` Michal Hocko
2021-02-18 1:00 ` Mike Kravetz
2021-02-18 3:20 ` Muchun Song
2021-02-18 8:21 ` Michal Hocko
2021-02-15 12:24 ` Michal Hocko
2021-02-08 8:50 ` [PATCH v15 5/8] mm: hugetlb: add a kernel parameter hugetlb_free_vmemmap Muchun Song
2021-02-08 8:50 ` Muchun Song [this message]
2021-02-08 8:50 ` [PATCH v15 7/8] mm: hugetlb: gather discrete indexes of tail page Muchun Song
2021-02-08 8:50 ` [PATCH v15 8/8] mm: hugetlb: optimize the code with the help of the compiler Muchun Song
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