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 v5 17/21] mm/hugetlb: Add a kernel parameter hugetlb_free_vmemmap
Date: Fri, 20 Nov 2020 14:43:21 +0800 [thread overview]
Message-ID: <20201120064325.34492-18-songmuchun@bytedance.com> (raw)
In-Reply-To: <20201120064325.34492-1-songmuchun@bytedance.com>
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 +++
mm/hugetlb_vmemmap.c | 21 +++++++++++++++++++++
3 files changed, 33 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 5debfe238027..ccf07293cb63 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 (default) | off }
+
+ 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..7d6129ee97dd 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 disables freeing
+ unused vmemmap pages associated 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/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 3629165d8158..c958699d1393 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -144,6 +144,22 @@ static inline bool vmemmap_pmd_huge(pmd_t *pmd)
}
#endif
+static bool hugetlb_free_vmemmap_disabled __initdata;
+
+static int __init early_hugetlb_free_vmemmap_param(char *buf)
+{
+ if (!buf)
+ return -EINVAL;
+
+ if (!strcmp(buf, "off"))
+ hugetlb_free_vmemmap_disabled = true;
+ else if (strcmp(buf, "on"))
+ return -EINVAL;
+
+ return 0;
+}
+early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param);
+
static inline unsigned int vmemmap_pages_per_hpage(struct hstate *h)
{
return free_vmemmap_pages_per_hpage(h) + RESERVE_VMEMMAP_NR;
@@ -541,6 +557,11 @@ void __init hugetlb_vmemmap_init(struct hstate *h)
unsigned int order = huge_page_order(h);
unsigned int vmemmap_pages;
+ if (hugetlb_free_vmemmap_disabled) {
+ pr_info("disable free vmemmap pages for %s\n", h->name);
+ return;
+ }
+
vmemmap_pages = ((1 << order) * sizeof(struct page)) >> PAGE_SHIFT;
/*
* The head page and the first tail page are not to be freed to buddy
--
2.11.0
next prev parent reply other threads:[~2020-11-20 6:49 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 6:43 [PATCH v5 00/21] Free some vmemmap pages of hugetlb page Muchun Song
2020-11-20 6:43 ` [PATCH v5 01/21] mm/memory_hotplug: Move bootmem info registration API to bootmem_info.c Muchun Song
2020-11-20 6:43 ` [PATCH v5 02/21] mm/memory_hotplug: Move {get,put}_page_bootmem() " Muchun Song
2020-11-20 6:43 ` [PATCH v5 03/21] mm/hugetlb: Introduce a new config HUGETLB_PAGE_FREE_VMEMMAP Muchun Song
2020-11-20 7:49 ` Michal Hocko
2020-11-20 8:35 ` [External] " Muchun Song
2020-11-20 8:47 ` Michal Hocko
2020-11-20 8:53 ` Muchun Song
2020-11-20 6:43 ` [PATCH v5 04/21] mm/hugetlb: Introduce nr_free_vmemmap_pages in the struct hstate Muchun Song
2020-11-20 6:43 ` [PATCH v5 05/21] mm/hugetlb: Introduce pgtable allocation/freeing helpers Muchun Song
2020-11-20 6:43 ` [PATCH v5 06/21] mm/bootmem_info: Introduce {free,prepare}_vmemmap_page() Muchun Song
2020-11-20 6:43 ` [PATCH v5 07/21] mm/bootmem_info: Combine bootmem info and type into page->freelist Muchun Song
2020-11-20 6:43 ` [PATCH v5 08/21] mm/hugetlb: Initialize page table lock for vmemmap Muchun Song
2020-11-20 6:43 ` [PATCH v5 09/21] mm/hugetlb: Free the vmemmap pages associated with each hugetlb page Muchun Song
2020-11-20 6:43 ` [PATCH v5 10/21] mm/hugetlb: Defer freeing of hugetlb pages Muchun Song
2020-11-20 6:43 ` [PATCH v5 11/21] mm/hugetlb: Allocate the vmemmap pages associated with each hugetlb page Muchun Song
2020-11-20 8:11 ` Michal Hocko
2020-11-20 8:51 ` [External] " Muchun Song
2020-11-20 9:28 ` Michal Hocko
2020-11-20 9:37 ` Muchun Song
2020-11-20 11:10 ` Michal Hocko
2020-11-20 11:56 ` Muchun Song
2020-11-20 6:43 ` [PATCH v5 12/21] mm/hugetlb: Introduce remap_huge_page_pmd_vmemmap helper Muchun Song
2020-11-20 6:43 ` [PATCH v5 13/21] mm/hugetlb: Use PG_slab to indicate split pmd Muchun Song
2020-11-20 8:16 ` Michal Hocko
2020-11-20 9:30 ` [External] " Muchun Song
2020-11-23 7:48 ` Michal Hocko
2020-11-23 8:01 ` Muchun Song
2020-11-20 6:43 ` [PATCH v5 14/21] mm/hugetlb: Support freeing vmemmap pages of gigantic page Muchun Song
2020-11-20 6:43 ` [PATCH v5 15/21] mm/hugetlb: Set the PageHWPoison to the raw error page Muchun Song
2020-11-20 8:19 ` Michal Hocko
2020-11-20 10:32 ` [External] " Muchun Song
2020-11-20 6:43 ` [PATCH v5 16/21] mm/hugetlb: Flush work when dissolving hugetlb page Muchun Song
2020-11-20 8:20 ` Michal Hocko
2020-11-20 6:43 ` Muchun Song [this message]
2020-11-20 8:22 ` [PATCH v5 17/21] mm/hugetlb: Add a kernel parameter hugetlb_free_vmemmap Michal Hocko
2020-11-20 10:39 ` [External] " Muchun Song
2020-11-20 6:43 ` [PATCH v5 18/21] mm/hugetlb: Merge pte to huge pmd only for gigantic page Muchun Song
2020-11-20 8:23 ` Michal Hocko
2020-11-20 10:41 ` [External] " Muchun Song
2020-11-20 6:43 ` [PATCH v5 19/21] mm/hugetlb: Gather discrete indexes of tail page Muchun Song
2020-11-20 6:43 ` [PATCH v5 20/21] mm/hugetlb: Add BUILD_BUG_ON to catch invalid usage of tail struct page Muchun Song
2020-11-20 6:43 ` [PATCH v5 21/21] mm/hugetlb: Disable freeing vmemmap if struct page size is not power of two Muchun Song
2020-11-20 8:25 ` Michal Hocko
2020-11-20 9:15 ` David Hildenbrand
2020-11-22 13:30 ` Mike Rapoport
2020-11-22 19:00 ` Matthew Wilcox
2020-11-23 3:14 ` [External] " Muchun Song
2020-11-20 9:16 ` David Hildenbrand
2020-11-20 10:42 ` [External] " Muchun Song
2020-11-20 8:42 ` [PATCH v5 00/21] Free some vmemmap pages of hugetlb page Michal Hocko
2020-11-20 9:27 ` David Hildenbrand
2020-11-20 9:39 ` Michal Hocko
2020-11-20 9:43 ` David Hildenbrand
2020-11-20 17:45 ` Mike Kravetz
2020-11-20 18:00 ` David Hildenbrand
2020-11-22 7:29 ` [External] " Muchun Song
2020-11-23 7:38 ` Michal Hocko
2020-11-23 21:52 ` Mike Kravetz
2020-11-23 22:01 ` Matthew Wilcox
2020-11-20 12:40 ` [External] " Muchun Song
2020-11-20 13:11 ` Michal Hocko
2020-11-20 15:44 ` Muchun Song
2020-11-23 7:40 ` Michal Hocko
2020-11-23 8:53 ` Muchun Song
2020-11-23 9:43 ` Michal Hocko
2020-11-23 10:36 ` Muchun Song
2020-11-23 10:42 ` Michal Hocko
2020-11-23 11:16 ` Muchun Song
2020-11-23 11:32 ` Michal Hocko
2020-11-23 12:07 ` Muchun Song
2020-11-23 12:18 ` Michal Hocko
2020-11-23 12:40 ` Muchun Song
2020-11-23 12:48 ` Michal Hocko
2020-11-23 12:45 ` Matthew Wilcox
2020-11-23 13:05 ` Muchun Song
2020-11-23 13:13 ` Michal Hocko
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