On 10/04/2023 18:27, Jane Chu wrote: > > On 4/8/2023 3:19 AM, Aneesh Kumar K.V wrote: >> Jane Chu <jane.chu@xxxxxxxxxx> writes: >> >>> On 4/7/2023 5:23 AM, Aneesh Kumar K.V wrote: >>>> diff --git a/mm/Kconfig b/mm/Kconfig >>>> index ff7b209dec05..99f87c1be1e8 100644 >>>> --- a/mm/Kconfig >>>> +++ b/mm/Kconfig >>>> @@ -461,6 +461,9 @@ config SPARSEMEM_VMEMMAP >>>> pfn_to_page and page_to_pfn operations. This is the most >>>> efficient option when sufficient kernel resources are available. >>>> +config ARCH_WANT_OPTIMIZE_VMEMMAP >>>> + bool >>>> + >>> >>> Could this devdax specific config switch be added to drivers/dax/Kconfig >>> ? also, how about adding 'DAX' to the config switch name? >> >> I would say we want to make it more generic. ie, both hugetlb and devdax >> can now derive the feature support via ARCH_WANT_OPTIMIZE_VMEMAP > > The two config switches have different purposes, it's better to keep them > separate. For example, recent hugetlb high granularity mapping (HGM) project > requires to users to make a choice between HGM and hugetlb vmemmap > optimization(at least for now), while one can keep devdax compound page support > enabled. > Is it done by kconfig? If it helps: * there's a static key hugetlb can use to tell if this is enabled or not like how page_fixed_fake_head() uses it: if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key)) ... * there's a hugetlb page bit for that vmemmap optimized pages with HpageOptimized(page). * there is a separate hugetlb CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP which is not the same as the ARCH kconfig. But perhaps there's some relevance in the ARCH_HUGETLB specific to HGMv2 that I am unaware. >> >> commit aafb4790ea0250c8d2450e9d23a4be80c663d2ec >> Author: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> >> Date: Sat Apr 8 15:41:48 2023 +0530 >> >> mm/hugetlb: Remove ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP >> We can depend on the more generic ARCH_WACH_OPTIMIZE_VMEMAP >> which is now used to enable both hugetlb and devddax vmemmap optimization. >> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index d3f5945f0aff..77d9713dcd9c 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -100,7 +100,6 @@ config ARM64 >> select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT >> select ARCH_WANT_FRAME_POINTERS >> select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && >> !ARM64_VA_BITS_36) >> - select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP >> select ARCH_WANT_LD_ORPHAN_WARN >> select ARCH_WANTS_NO_INSTR >> select ARCH_WANT_OPTIMIZE_VMEMMAP >> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig >> index ce5802066d0e..9cb00f962de1 100644 >> --- a/arch/loongarch/Kconfig >> +++ b/arch/loongarch/Kconfig >> @@ -53,7 +53,6 @@ config LOONGARCH >> select ARCH_USE_QUEUED_RWLOCKS >> select ARCH_USE_QUEUED_SPINLOCKS >> select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT >> - select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP >> select ARCH_WANT_LD_ORPHAN_WARN >> select ARCH_WANTS_NO_INSTR >> select ARCH_WANT_OPTIMIZE_VMEMMAP >> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig >> index abffccd937b2..df2cd510480a 100644 >> --- a/arch/s390/Kconfig >> +++ b/arch/s390/Kconfig >> @@ -126,7 +126,6 @@ config S390 >> select ARCH_WANTS_NO_INSTR >> select ARCH_WANT_DEFAULT_BPF_JIT >> select ARCH_WANT_IPC_PARSE_VERSION >> - select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP >> select ARCH_WANT_OPTIMIZE_VMEMMAP >> select BUILDTIME_TABLE_SORT >> select CLONE_BACKWARDS2 >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index e8d66d834b4f..5269131cc248 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -125,7 +125,6 @@ config X86 >> select ARCH_WANTS_NO_INSTR >> select ARCH_WANT_GENERAL_HUGETLB >> select ARCH_WANT_HUGE_PMD_SHARE >> - select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP if X86_64 >> select ARCH_WANT_LD_ORPHAN_WARN >> select ARCH_WANT_OPTIMIZE_VMEMMAP if X86_64 >> select ARCH_WANTS_THP_SWAP if X86_64 >> diff --git a/fs/Kconfig b/fs/Kconfig >> index e99830c65033..cc07a0cd3172 100644 >> --- a/fs/Kconfig >> +++ b/fs/Kconfig >> @@ -250,16 +250,9 @@ 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 HugeTLB Vmemmap Optimization (HVO). >> -# >> -config ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP >> - bool >> - >> config HUGETLB_PAGE_OPTIMIZE_VMEMMAP >> def_bool HUGETLB_PAGE >> - depends on ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP >> + depends on ARCH_WANT_OPTIMIZE_VMEMMAP >> depends on SPARSEMEM_VMEMMAP >> config HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON >> diff --git a/mm/Kconfig b/mm/Kconfig >> index 99f87c1be1e8..09ac60894763 100644 >> --- a/mm/Kconfig >> +++ b/mm/Kconfig >> @@ -460,7 +460,10 @@ config SPARSEMEM_VMEMMAP >> SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise >> pfn_to_page and page_to_pfn operations. This is the most >> efficient option when sufficient kernel resources are available. >> - >> +# >> +# Select this config option from the architecture Kconfig, if it is preferred >> +# to enable the feature of HugeTLB/dev_dax vmemmap optimization. >> +# >> config ARCH_WANT_OPTIMIZE_VMEMMAP >> bool >> > > thanks, > -jane
