Hi,
Please see comments below.
On 9/15/20 5:59 AM, Muchun Song wrote:
> 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@xxxxxxxxxxxxx>
> ---
> .../admin-guide/kernel-parameters.txt | 9 ++++++++
> Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++
> mm/hugetlb.c | 23 +++++++++++++++++++
> 3 files changed, 35 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 5debfe238027..69d18ef6f66b 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 disables freeing unused vmemmap pages associated
this controls
> + each HugeTLB page.
with each HugeTLB page.
> + Format: { on (default) | off }
> +
> + on: enable the feature
> + off: dosable the feature
disable
> +
> 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.
insert blank line here.
> +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.
--
~Randy
