On 31.03.22 08:56, Muchun Song wrote: > The feature of minimizing overhead of struct page associated with each > HugeTLB page is implemented on x86_64, however, the infrastructure of > this feature is already there, we could easily enable it for other > architectures. Introduce ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP for other > architectures to be easily enabled. Just select this config if they > want to enable this feature. > > Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > --- > arch/x86/Kconfig | 1 + > fs/Kconfig | 10 +++++++++- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 9f5bd41bf660..e69d42528542 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -119,6 +119,7 @@ config X86 > select ARCH_WANTS_DYNAMIC_TASK_STRUCT > select ARCH_WANTS_NO_INSTR > select ARCH_WANT_HUGE_PMD_SHARE > + select ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP if X86_64 > select ARCH_WANT_LD_ORPHAN_WARN > select ARCH_WANTS_THP_SWAP if X86_64 > select ARCH_HAS_PARANOID_L1D_FLUSH > diff --git a/fs/Kconfig b/fs/Kconfig > index 6c7dc1387beb..f6db2af33738 100644 > --- a/fs/Kconfig > +++ b/fs/Kconfig > @@ -245,9 +245,17 @@ config HUGETLBFS > config HUGETLB_PAGE > def_bool HUGETLBFS > > +# > +# Select this config option from the architecture Kconfig, if it is preferred > +# to enable the feature of minimizing overhead of struct page associated with > +# each HugeTLB page. > +# > +config ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP > + bool > + > config HUGETLB_PAGE_FREE_VMEMMAP > def_bool HUGETLB_PAGE > - depends on X86_64 > + depends on ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP > depends on SPARSEMEM_VMEMMAP > > config HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON I think something like "HUGETLB_OPTIMIZE_VMEMMAP" might be more expressive, but that would imply renaming the existing config knob. Apart from that LGTM. -- Thanks, David / dhildenb
