The patch titled
Subject: mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON
has been added to the -mm tree. Its filename is
mm-hugetlb-introduce-config_hugetlb_page_free_vmemmap_default_on.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-introduce-config_hugetlb_page_free_vmemmap_default_on.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-introduce-config_hugetlb_page_free_vmemmap_default_on.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
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there every 3-4 working days
------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON
When using HUGETLB_PAGE_FREE_VMEMMAP, the freeing unused vmemmap pages
associated with each HugeTLB page is default off. Now the vmemmap is PMD
mapped. So there is no side effect when this feature is enabled with no
HugeTLB pages in the system. Someone may want to enable this feature in
the compiler time instead of using boot command line. So add a config to
make it default on when someone do not want to enable it via command line.
Link: https://lkml.kernel.org/r/20210616094915.34432-4-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Chen Huang <chenhuang5@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 3 +++
fs/Kconfig | 10 ++++++++++
mm/hugetlb_vmemmap.c | 6 ++++--
3 files changed, 17 insertions(+), 2 deletions(-)
--- a/Documentation/admin-guide/kernel-parameters.txt~mm-hugetlb-introduce-config_hugetlb_page_free_vmemmap_default_on
+++ a/Documentation/admin-guide/kernel-parameters.txt
@@ -1577,6 +1577,9 @@
on: enable the feature
off: disable the feature
+ Built with CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON=y,
+ the default is on.
+
This is not compatible with memory_hotplug.memmap_on_memory.
If both parameters are enabled, hugetlb_free_vmemmap takes
precedence over memory_hotplug.memmap_on_memory.
--- a/fs/Kconfig~mm-hugetlb-introduce-config_hugetlb_page_free_vmemmap_default_on
+++ a/fs/Kconfig
@@ -245,6 +245,16 @@ config HUGETLB_PAGE_FREE_VMEMMAP
depends on X86_64
depends on SPARSEMEM_VMEMMAP
+config HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON
+ bool "Default freeing vmemmap pages of HugeTLB to on"
+ default n
+ depends on HUGETLB_PAGE_FREE_VMEMMAP
+ help
+ When using HUGETLB_PAGE_FREE_VMEMMAP, the freeing unused vmemmap
+ pages associated with each HugeTLB page is default off. Say Y here
+ to enable freeing vmemmap pages of HugeTLB by default. It can then
+ be disabled on the command line via hugetlb_free_vmemmap=off.
+
config MEMFD_CREATE
def_bool TMPFS || HUGETLBFS
--- a/mm/hugetlb_vmemmap.c~mm-hugetlb-introduce-config_hugetlb_page_free_vmemmap_default_on
+++ a/mm/hugetlb_vmemmap.c
@@ -182,7 +182,7 @@
#define RESERVE_VMEMMAP_NR 2U
#define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT)
-bool hugetlb_free_vmemmap_enabled;
+bool hugetlb_free_vmemmap_enabled = IS_ENABLED(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON);
static int __init early_hugetlb_free_vmemmap_param(char *buf)
{
@@ -197,7 +197,9 @@ static int __init early_hugetlb_free_vme
if (!strcmp(buf, "on"))
hugetlb_free_vmemmap_enabled = true;
- else if (strcmp(buf, "off"))
+ else if (!strcmp(buf, "off"))
+ hugetlb_free_vmemmap_enabled = false;
+ else
return -EINVAL;
return 0;
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-memcontrol-fix-root_mem_cgroup-charging.patch
mm-memcontrol-fix-page-charging-in-page-replacement.patch
mm-memcontrol-bail-out-early-when-mm-in-get_mem_cgroup_from_mm.patch
mm-memcontrol-remove-the-pgdata-parameter-of-mem_cgroup_page_lruvec.patch
mm-memcontrol-simplify-lruvec_holds_page_lru_lock.patch
mm-memcontrol-rename-lruvec_holds_page_lru_lock-to-page_matches_lruvec.patch
mm-memcontrol-simplify-the-logic-of-objcg-pinning-memcg.patch
mm-memcontrol-move-obj_cgroup_uncharge_pages-out-of-css_set_lock.patch
mm-vmscan-remove-noinline_for_stack.patch
mm-memory_hotplug-factor-out-bootmem-core-functions-to-bootmem_infoc.patch
mm-hugetlb-introduce-a-new-config-hugetlb_page_free_vmemmap.patch
mm-hugetlb-gather-discrete-indexes-of-tail-page.patch
mm-hugetlb-free-the-vmemmap-pages-associated-with-each-hugetlb-page.patch
mm-hugetlb-defer-freeing-of-hugetlb-pages.patch
mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page.patch
mm-hugetlb-add-a-kernel-parameter-hugetlb_free_vmemmap.patch
mm-memory_hotplug-disable-memmap_on_memory-when-hugetlb_free_vmemmap-enabled.patch
mm-hugetlb-introduce-nr_free_vmemmap_pages-in-the-struct-hstate.patch
mm-sparsemem-split-the-huge-pmd-mapping-of-vmemmap-pages.patch
mm-sparsemem-use-huge-pmd-mapping-for-vmemmap-pages.patch
mm-hugetlb-introduce-config_hugetlb_page_free_vmemmap_default_on.patch
mm-migrate-fix-missing-update-page_private-to-hugetlb_page_subpool.patch
mm-migrate-fix-missing-update-page_private-to-hugetlb_page_subpool-v2.patch
