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
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>
Subject: [PATCH v6 15/16] mm/hugetlb: Gather discrete indexes of tail page
Date: Tue, 24 Nov 2020 17:52:58 +0800 [thread overview]
Message-ID: <20201124095259.58755-16-songmuchun@bytedance.com> (raw)
In-Reply-To: <20201124095259.58755-1-songmuchun@bytedance.com>
For hugetlb page, there are more metadata to save in the struct
page. But the head struct page cannot meet our needs, so we have
to abuse other tail struct page to store the metadata. In order
to avoid conflicts caused by subsequent use of more tail struct
pages, we can gather these discrete indexes of tail struct page
In this case, it will be easier to add a new tail page index later.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
include/linux/hugetlb.h | 13 +++++++++++++
include/linux/hugetlb_cgroup.h | 15 +++++++++------
mm/hugetlb.c | 12 ++++++------
mm/hugetlb_vmemmap.h | 4 ++--
4 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index eed3dd3bd626..8a615ae2d233 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -28,6 +28,19 @@ typedef struct { unsigned long pd; } hugepd_t;
#include <linux/shm.h>
#include <asm/tlbflush.h>
+enum {
+ SUBPAGE_INDEX_ACTIVE = 1, /* reuse page flags of PG_private */
+ SUBPAGE_INDEX_TEMPORARY, /* reuse page->mapping */
+#ifdef CONFIG_CGROUP_HUGETLB
+ SUBPAGE_INDEX_CGROUP = SUBPAGE_INDEX_TEMPORARY,/* reuse page->private */
+ SUBPAGE_INDEX_CGROUP_RSVD, /* reuse page->private */
+#endif
+#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+ SUBPAGE_INDEX_HWPOISON, /* reuse page->private */
+#endif
+ NR_USED_SUBPAGE,
+};
+
struct hugepage_subpool {
spinlock_t lock;
long count;
diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index 2ad6e92f124a..3d3c1c49efe4 100644
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -24,8 +24,9 @@ struct file_region;
/*
* Minimum page order trackable by hugetlb cgroup.
* At least 4 pages are necessary for all the tracking information.
- * The second tail page (hpage[2]) is the fault usage cgroup.
- * The third tail page (hpage[3]) is the reservation usage cgroup.
+ * The second tail page (hpage[SUBPAGE_INDEX_CGROUP]) is the fault
+ * usage cgroup. The third tail page (hpage[SUBPAGE_INDEX_CGROUP_RSVD])
+ * is the reservation usage cgroup.
*/
#define HUGETLB_CGROUP_MIN_ORDER 2
@@ -66,9 +67,9 @@ __hugetlb_cgroup_from_page(struct page *page, bool rsvd)
if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
return NULL;
if (rsvd)
- return (struct hugetlb_cgroup *)page[3].private;
+ return (void *)page_private(page + SUBPAGE_INDEX_CGROUP_RSVD);
else
- return (struct hugetlb_cgroup *)page[2].private;
+ return (void *)page_private(page + SUBPAGE_INDEX_CGROUP);
}
static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
@@ -90,9 +91,11 @@ static inline int __set_hugetlb_cgroup(struct page *page,
if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
return -1;
if (rsvd)
- page[3].private = (unsigned long)h_cg;
+ set_page_private(page + SUBPAGE_INDEX_CGROUP_RSVD,
+ (unsigned long)h_cg);
else
- page[2].private = (unsigned long)h_cg;
+ set_page_private(page + SUBPAGE_INDEX_CGROUP,
+ (unsigned long)h_cg);
return 0;
}
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 15e2c1dd32ea..7700da372716 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1429,20 +1429,20 @@ struct hstate *size_to_hstate(unsigned long size)
bool page_huge_active(struct page *page)
{
VM_BUG_ON_PAGE(!PageHuge(page), page);
- return PageHead(page) && PagePrivate(&page[1]);
+ return PageHead(page) && PagePrivate(&page[SUBPAGE_INDEX_ACTIVE]);
}
/* never called for tail page */
static void set_page_huge_active(struct page *page)
{
VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
- SetPagePrivate(&page[1]);
+ SetPagePrivate(&page[SUBPAGE_INDEX_ACTIVE]);
}
static void clear_page_huge_active(struct page *page)
{
VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
- ClearPagePrivate(&page[1]);
+ ClearPagePrivate(&page[SUBPAGE_INDEX_ACTIVE]);
}
/*
@@ -1454,17 +1454,17 @@ static inline bool PageHugeTemporary(struct page *page)
if (!PageHuge(page))
return false;
- return (unsigned long)page[2].mapping == -1U;
+ return (unsigned long)page[SUBPAGE_INDEX_TEMPORARY].mapping == -1U;
}
static inline void SetPageHugeTemporary(struct page *page)
{
- page[2].mapping = (void *)-1U;
+ page[SUBPAGE_INDEX_TEMPORARY].mapping = (void *)-1U;
}
static inline void ClearPageHugeTemporary(struct page *page)
{
- page[2].mapping = NULL;
+ page[SUBPAGE_INDEX_TEMPORARY].mapping = NULL;
}
static void __free_huge_page(struct page *page)
diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h
index 4bb35d87ae10..54c2ca0e0dbe 100644
--- a/mm/hugetlb_vmemmap.h
+++ b/mm/hugetlb_vmemmap.h
@@ -20,7 +20,7 @@ static inline void subpage_hwpoison_deliver(struct page *head)
struct page *page = head;
if (PageHWPoison(head))
- page = head + page_private(head + 4);
+ page = head + page_private(head + SUBPAGE_INDEX_HWPOISON);
/*
* Move PageHWPoison flag from head page to the raw error page,
@@ -35,7 +35,7 @@ static inline void subpage_hwpoison_deliver(struct page *head)
static inline void set_subpage_hwpoison(struct page *head, struct page *page)
{
if (PageHWPoison(head))
- set_page_private(head + 4, page - head);
+ set_page_private(head + SUBPAGE_INDEX_HWPOISON, page - head);
}
static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h)
--
2.11.0
next prev parent reply other threads:[~2020-11-24 9:59 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-24 9:52 [PATCH v6 00/16] Free some vmemmap pages of hugetlb page Muchun Song
2020-11-24 9:52 ` [PATCH v6 01/16] mm/memory_hotplug: Move bootmem info registration API to bootmem_info.c Muchun Song
2021-06-10 12:15 ` chengkaitao
2020-11-24 9:52 ` [PATCH v6 02/16] mm/memory_hotplug: Move {get,put}_page_bootmem() " Muchun Song
2020-11-24 9:52 ` [PATCH v6 03/16] mm/hugetlb: Introduce a new config HUGETLB_PAGE_FREE_VMEMMAP Muchun Song
2020-11-24 9:52 ` [PATCH v6 04/16] mm/hugetlb: Introduce nr_free_vmemmap_pages in the struct hstate Muchun Song
2020-11-24 9:52 ` [PATCH v6 05/16] mm/bootmem_info: Introduce {free,prepare}_vmemmap_page() Muchun Song
2020-11-24 9:52 ` [PATCH v6 06/16] mm/hugetlb: Disable freeing vmemmap if struct page size is not power of two Muchun Song
2020-11-24 9:52 ` [PATCH v6 07/16] x86/mm/64: Disable PMD page mapping of vmemmap Muchun Song
2020-11-24 10:24 ` Oscar Salvador
2020-11-24 10:31 ` Song Bao Hua (Barry Song)
2020-11-24 11:13 ` [External] " Muchun Song
2020-11-24 9:52 ` [PATCH v6 08/16] mm/hugetlb: Free the vmemmap pages associated with each hugetlb page Muchun Song
2020-11-24 9:52 ` [PATCH v6 09/16] mm/hugetlb: Defer freeing of HugeTLB pages Muchun Song
2020-11-24 11:51 ` Michal Hocko
2020-11-24 12:45 ` [External] " Muchun Song
2020-11-24 13:14 ` Michal Hocko
2020-11-24 9:52 ` [PATCH v6 10/16] mm/hugetlb: Allocate the vmemmap pages associated with each hugetlb page Muchun Song
2020-11-24 9:52 ` [PATCH v6 11/16] mm/hugetlb: Introduce remap_huge_page_pmd_vmemmap helper Muchun Song
2020-11-24 9:52 ` [PATCH v6 12/16] mm/hugetlb: Set the PageHWPoison to the raw error page Muchun Song
2020-11-24 9:52 ` [PATCH v6 13/16] mm/hugetlb: Flush work when dissolving hugetlb page Muchun Song
2020-11-24 9:52 ` [PATCH v6 14/16] mm/hugetlb: Add a kernel parameter hugetlb_free_vmemmap Muchun Song
2020-11-24 10:53 ` Song Bao Hua (Barry Song)
2020-11-24 11:07 ` [External] " Muchun Song
2020-11-24 9:52 ` Muchun Song [this message]
2020-11-24 9:52 ` [PATCH v6 16/16] mm/hugetlb: Add BUILD_BUG_ON to catch invalid usage of tail struct page Muchun Song
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