On Mon, Jun 13, 2022 at 05:39:59PM +0200, David Hildenbrand wrote: > On 13.06.22 08:35, Muchun Song wrote: > > It it inconvenient to mention the feature of optimizing vmemmap pages associated > > with HugeTLB pages when communicating with others since there is no specific or > > abbreviated name for it when it is first introduced. Let us give it a name HVO > > (HugeTLB Vmemmap Optimization) from now. > > > > This commit also updates the document about "hugetlb_free_vmemmap" by the way > > discussed in thread [1]. > > > > Link: https://lore.kernel.org/all/21aae898-d54d-cc4b-a11f-1bb7fddcfffa@xxxxxxxxxx/ [1] > > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > > --- > > Documentation/admin-guide/kernel-parameters.txt | 7 ++++--- > > Documentation/admin-guide/mm/hugetlbpage.rst | 3 +-- > > Documentation/admin-guide/sysctl/vm.rst | 3 +-- > > fs/Kconfig | 13 ++++++------- > > mm/hugetlb_vmemmap.c | 8 ++++---- > > mm/hugetlb_vmemmap.h | 4 ++-- > > 6 files changed, 18 insertions(+), 20 deletions(-) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > index 391b43fee93e..7539553b3fb0 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -1725,12 +1725,13 @@ > > hugetlb_free_vmemmap= > > [KNL] Reguires CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > > enabled. > > + Control if HugeTLB Vmemmap Optimization (HVO) is enabled. > > Allows heavy hugetlb users to free up some more > > memory (7 * PAGE_SIZE for each 2MB hugetlb page). > > - Format: { [oO][Nn]/Y/y/1 | [oO][Ff]/N/n/0 (default) } > > + Format: { on | off (default) } > > > > - [oO][Nn]/Y/y/1: enable the feature > > - [oO][Ff]/N/n/0: disable the feature > > + on: enable HVO > > + off: disable HVO > > > > Built with CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON=y, > > the default is on. > > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst > > index a90330d0a837..64e0d5c512e7 100644 > > --- a/Documentation/admin-guide/mm/hugetlbpage.rst > > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst > > @@ -164,8 +164,7 @@ 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_OPTIMIZE_VMEMMAP is set, this enables optimizing > > - unused vmemmap pages associated with each HugeTLB page. > > + When CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP is set, this enables HVO. > > Heh, it would be convenient to call this > > CONFIG_HUGETLB_PAGE_VMEMMAP_OPTIMIZATION (HVO) then. > Thanks for pointing it out. I would take Mike's suggestion. I would change to: When CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP is set this enables HugeTLB Vmemmap Optimization (HVO). Thanks.
