| Message ID | 20240809160909.1023470-2-peterx@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: Support huge pfnmaps | expand |
On 09.08.24 18:08, Peter Xu wrote: > This patch introduces the option to introduce special pte bit into > pmd/puds. Archs can start to define pmd_special / pud_special when > supported by selecting the new option. Per-arch support will be added > later. > > Before that, create fallbacks for these helpers so that they are always > available. > > Signed-off-by: Peter Xu <peterx@redhat.com> > --- > include/linux/mm.h | 24 ++++++++++++++++++++++++ > mm/Kconfig | 13 +++++++++++++ > 2 files changed, 37 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 43b40334e9b2..90ca84200800 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2644,6 +2644,30 @@ static inline pte_t pte_mkspecial(pte_t pte) > } > #endif > > +#ifndef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP > +static inline bool pmd_special(pmd_t pmd) > +{ > + return false; > +} > + > +static inline pmd_t pmd_mkspecial(pmd_t pmd) > +{ > + return pmd; > +} > +#endif /* CONFIG_ARCH_SUPPORTS_PMD_PFNMAP */ > + > +#ifndef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP > +static inline bool pud_special(pud_t pud) > +{ > + return false; > +} > + > +static inline pud_t pud_mkspecial(pud_t pud) > +{ > + return pud; > +} > +#endif /* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */ > + > #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP > static inline int pte_devmap(pte_t pte) > { > diff --git a/mm/Kconfig b/mm/Kconfig > index 3936fe4d26d9..3db0eebb53e2 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -881,6 +881,19 @@ endif # TRANSPARENT_HUGEPAGE > config PGTABLE_HAS_HUGE_LEAVES > def_bool TRANSPARENT_HUGEPAGE || HUGETLB_PAGE > > +# TODO: Allow to be enabled without THP > +config ARCH_SUPPORTS_HUGE_PFNMAP > + def_bool n > + depends on TRANSPARENT_HUGEPAGE > + > +config ARCH_SUPPORTS_PMD_PFNMAP > + def_bool y > + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE > + > +config ARCH_SUPPORTS_PUD_PFNMAP > + def_bool y > + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD > + > # > # UP and nommu archs use km based percpu allocator > # As noted in reply to other patches, I think you have to take care of vm_normal_page_pmd() [if not done in another patch I am missing] and likely you want to introduce vm_normal_page_pud().
On Fri, Aug 09, 2024 at 06:34:15PM +0200, David Hildenbrand wrote: > On 09.08.24 18:08, Peter Xu wrote: > > This patch introduces the option to introduce special pte bit into > > pmd/puds. Archs can start to define pmd_special / pud_special when > > supported by selecting the new option. Per-arch support will be added > > later. > > > > Before that, create fallbacks for these helpers so that they are always > > available. > > > > Signed-off-by: Peter Xu <peterx@redhat.com> > > --- > > include/linux/mm.h | 24 ++++++++++++++++++++++++ > > mm/Kconfig | 13 +++++++++++++ > > 2 files changed, 37 insertions(+) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index 43b40334e9b2..90ca84200800 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -2644,6 +2644,30 @@ static inline pte_t pte_mkspecial(pte_t pte) > > } > > #endif > > +#ifndef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP > > +static inline bool pmd_special(pmd_t pmd) > > +{ > > + return false; > > +} > > + > > +static inline pmd_t pmd_mkspecial(pmd_t pmd) > > +{ > > + return pmd; > > +} > > +#endif /* CONFIG_ARCH_SUPPORTS_PMD_PFNMAP */ > > + > > +#ifndef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP > > +static inline bool pud_special(pud_t pud) > > +{ > > + return false; > > +} > > + > > +static inline pud_t pud_mkspecial(pud_t pud) > > +{ > > + return pud; > > +} > > +#endif /* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */ > > + > > #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP > > static inline int pte_devmap(pte_t pte) > > { > > diff --git a/mm/Kconfig b/mm/Kconfig > > index 3936fe4d26d9..3db0eebb53e2 100644 > > --- a/mm/Kconfig > > +++ b/mm/Kconfig > > @@ -881,6 +881,19 @@ endif # TRANSPARENT_HUGEPAGE > > config PGTABLE_HAS_HUGE_LEAVES > > def_bool TRANSPARENT_HUGEPAGE || HUGETLB_PAGE > > +# TODO: Allow to be enabled without THP > > +config ARCH_SUPPORTS_HUGE_PFNMAP > > + def_bool n > > + depends on TRANSPARENT_HUGEPAGE > > + > > +config ARCH_SUPPORTS_PMD_PFNMAP > > + def_bool y > > + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE > > + > > +config ARCH_SUPPORTS_PUD_PFNMAP > > + def_bool y > > + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD > > + > > # > > # UP and nommu archs use km based percpu allocator > > # > > As noted in reply to other patches, I think you have to take care of > vm_normal_page_pmd() [if not done in another patch I am missing] and likely > you want to introduce vm_normal_page_pud(). So far this patch may not have direct involvement with vm_normal_page_pud() yet? Anyway, let's keep the discussion there, then we'll know how to move on. Thanks,
On 09.08.24 19:16, Peter Xu wrote: > On Fri, Aug 09, 2024 at 06:34:15PM +0200, David Hildenbrand wrote: >> On 09.08.24 18:08, Peter Xu wrote: >>> This patch introduces the option to introduce special pte bit into >>> pmd/puds. Archs can start to define pmd_special / pud_special when >>> supported by selecting the new option. Per-arch support will be added >>> later. >>> >>> Before that, create fallbacks for these helpers so that they are always >>> available. >>> >>> Signed-off-by: Peter Xu <peterx@redhat.com> >>> --- >>> include/linux/mm.h | 24 ++++++++++++++++++++++++ >>> mm/Kconfig | 13 +++++++++++++ >>> 2 files changed, 37 insertions(+) >>> >>> diff --git a/include/linux/mm.h b/include/linux/mm.h >>> index 43b40334e9b2..90ca84200800 100644 >>> --- a/include/linux/mm.h >>> +++ b/include/linux/mm.h >>> @@ -2644,6 +2644,30 @@ static inline pte_t pte_mkspecial(pte_t pte) >>> } >>> #endif >>> +#ifndef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP >>> +static inline bool pmd_special(pmd_t pmd) >>> +{ >>> + return false; >>> +} >>> + >>> +static inline pmd_t pmd_mkspecial(pmd_t pmd) >>> +{ >>> + return pmd; >>> +} >>> +#endif /* CONFIG_ARCH_SUPPORTS_PMD_PFNMAP */ >>> + >>> +#ifndef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP >>> +static inline bool pud_special(pud_t pud) >>> +{ >>> + return false; >>> +} >>> + >>> +static inline pud_t pud_mkspecial(pud_t pud) >>> +{ >>> + return pud; >>> +} >>> +#endif /* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */ >>> + >>> #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP >>> static inline int pte_devmap(pte_t pte) >>> { >>> diff --git a/mm/Kconfig b/mm/Kconfig >>> index 3936fe4d26d9..3db0eebb53e2 100644 >>> --- a/mm/Kconfig >>> +++ b/mm/Kconfig >>> @@ -881,6 +881,19 @@ endif # TRANSPARENT_HUGEPAGE >>> config PGTABLE_HAS_HUGE_LEAVES >>> def_bool TRANSPARENT_HUGEPAGE || HUGETLB_PAGE >>> +# TODO: Allow to be enabled without THP >>> +config ARCH_SUPPORTS_HUGE_PFNMAP >>> + def_bool n >>> + depends on TRANSPARENT_HUGEPAGE >>> + >>> +config ARCH_SUPPORTS_PMD_PFNMAP >>> + def_bool y >>> + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE >>> + >>> +config ARCH_SUPPORTS_PUD_PFNMAP >>> + def_bool y >>> + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD >>> + >>> # >>> # UP and nommu archs use km based percpu allocator >>> # >> >> As noted in reply to other patches, I think you have to take care of >> vm_normal_page_pmd() [if not done in another patch I am missing] and likely >> you want to introduce vm_normal_page_pud(). > > So far this patch may not have direct involvement with vm_normal_page_pud() > yet? Anyway, let's keep the discussion there, then we'll know how to move > on. vm_normal_page_pud() might make sense as of today already, primarily to wrap the pud_devmap() stuff (maybe that is gone soon, who knows). Anyhow, I can send a patch to add that as well.
diff --git a/include/linux/mm.h b/include/linux/mm.h index 43b40334e9b2..90ca84200800 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2644,6 +2644,30 @@ static inline pte_t pte_mkspecial(pte_t pte) } #endif +#ifndef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP +static inline bool pmd_special(pmd_t pmd) +{ + return false; +} + +static inline pmd_t pmd_mkspecial(pmd_t pmd) +{ + return pmd; +} +#endif /* CONFIG_ARCH_SUPPORTS_PMD_PFNMAP */ + +#ifndef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP +static inline bool pud_special(pud_t pud) +{ + return false; +} + +static inline pud_t pud_mkspecial(pud_t pud) +{ + return pud; +} +#endif /* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */ + #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP static inline int pte_devmap(pte_t pte) { diff --git a/mm/Kconfig b/mm/Kconfig index 3936fe4d26d9..3db0eebb53e2 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -881,6 +881,19 @@ endif # TRANSPARENT_HUGEPAGE config PGTABLE_HAS_HUGE_LEAVES def_bool TRANSPARENT_HUGEPAGE || HUGETLB_PAGE +# TODO: Allow to be enabled without THP +config ARCH_SUPPORTS_HUGE_PFNMAP + def_bool n + depends on TRANSPARENT_HUGEPAGE + +config ARCH_SUPPORTS_PMD_PFNMAP + def_bool y + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE + +config ARCH_SUPPORTS_PUD_PFNMAP + def_bool y + depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD + # # UP and nommu archs use km based percpu allocator #
This patch introduces the option to introduce special pte bit into pmd/puds. Archs can start to define pmd_special / pud_special when supported by selecting the new option. Per-arch support will be added later. Before that, create fallbacks for these helpers so that they are always available. Signed-off-by: Peter Xu <peterx@redhat.com> --- include/linux/mm.h | 24 ++++++++++++++++++++++++ mm/Kconfig | 13 +++++++++++++ 2 files changed, 37 insertions(+)