| Message ID | 1539621759-5967-2-git-send-email-schwidefsky@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | pgtable bytes mis-accounting v2 | expand |
On Mon, Oct 15, 2018 at 06:42:37PM +0200, Martin Schwidefsky wrote: > Add three architecture overrideable function to test if the > p4d, pud, or pmd layer of a page table is folded or not. > > Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> > --- > include/linux/mm.h | 40 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 0416a7204be3..d1029972541c 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h Shouldn't it be somewhere in asm-generic/pgtable*? > @@ -105,6 +105,46 @@ extern int mmap_rnd_compat_bits __read_mostly; > #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page))) > #endif > > +/* > + * On some architectures it depends on the mm if the p4d/pud or pmd > + * layer of the page table hierarchy is folded or not. > + */ > +#ifndef mm_p4d_folded > +#define mm_p4d_folded(mm) mm_p4d_folded(mm) Do we need to define it in generic header? > +static inline bool mm_p4d_folded(struct mm_struct *mm) > +{ > +#ifdef __PAGETABLE_P4D_FOLDED > + return 1; > +#else > + return 0; > +#endif Maybe return __is_defined(__PAGETABLE_P4D_FOLDED); ?
On Wed, 31 Oct 2018 12:02:55 +0300 "Kirill A. Shutemov" <kirill@shutemov.name> wrote: > On Mon, Oct 15, 2018 at 06:42:37PM +0200, Martin Schwidefsky wrote: > > Add three architecture overrideable function to test if the > > p4d, pud, or pmd layer of a page table is folded or not. > > > > Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> > > --- > > include/linux/mm.h | 40 ++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 40 insertions(+) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index 0416a7204be3..d1029972541c 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > Shouldn't it be somewhere in asm-generic/pgtable*? If you prefer the definitions in asm-generic that is fine with me. I'll give it a try to see if it still compiles. > > @@ -105,6 +105,46 @@ extern int mmap_rnd_compat_bits __read_mostly; > > #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page))) > > #endif > > > > +/* > > + * On some architectures it depends on the mm if the p4d/pud or pmd > > + * layer of the page table hierarchy is folded or not. > > + */ > > +#ifndef mm_p4d_folded > > +#define mm_p4d_folded(mm) mm_p4d_folded(mm) > > Do we need to define it in generic header? That is true, it should work without the #define in the generic header. > > +static inline bool mm_p4d_folded(struct mm_struct *mm) > > +{ > > +#ifdef __PAGETABLE_P4D_FOLDED > > + return 1; > > +#else > > + return 0; > > +#endif > > Maybe > return __is_defined(__PAGETABLE_P4D_FOLDED); > > ? I have tried that, doesn't work. The reason is that the __PAGETABLE_xxx_FOLDED defines to not have a value. #define __PAGETABLE_P4D_FOLDED #define __PAGETABLE_PMD_FOLDED #define __PAGETABLE_PUD_FOLDED While the definition of CONFIG_xxx symbols looks like this #define CONFIG_xxx 1 The __is_defined needs the value for the __take_second_arg trick.
On Wed, Oct 31, 2018 at 10:35:36AM +0100, Martin Schwidefsky wrote: > > Maybe > > return __is_defined(__PAGETABLE_P4D_FOLDED); > > > > ? > > I have tried that, doesn't work. The reason is that the > __PAGETABLE_xxx_FOLDED defines to not have a value. > > #define __PAGETABLE_P4D_FOLDED > #define __PAGETABLE_PMD_FOLDED > #define __PAGETABLE_PUD_FOLDED > > While the definition of CONFIG_xxx symbols looks like this > > #define CONFIG_xxx 1 > > The __is_defined needs the value for the __take_second_arg trick. I guess this is easily fixable :)
diff --git a/include/linux/mm.h b/include/linux/mm.h index 0416a7204be3..d1029972541c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -105,6 +105,46 @@ extern int mmap_rnd_compat_bits __read_mostly; #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page))) #endif +/* + * On some architectures it depends on the mm if the p4d/pud or pmd + * layer of the page table hierarchy is folded or not. + */ +#ifndef mm_p4d_folded +#define mm_p4d_folded(mm) mm_p4d_folded(mm) +static inline bool mm_p4d_folded(struct mm_struct *mm) +{ +#ifdef __PAGETABLE_P4D_FOLDED + return 1; +#else + return 0; +#endif +} +#endif + +#ifndef mm_pud_folded +#define mm_pud_folded(mm) mm_pud_folded(mm) +static inline bool mm_pud_folded(struct mm_struct *mm) +{ +#ifdef __PAGETABLE_PUD_FOLDED + return 1; +#else + return 0; +#endif +} +#endif + +#ifndef mm_pmd_folded +#define mm_pmd_folded(mm) mm_pmd_folded(mm) +static inline bool mm_pmd_folded(struct mm_struct *mm) +{ +#ifdef __PAGETABLE_PMD_FOLDED + return 1; +#else + return 0; +#endif +} +#endif + /* * Default maximum number of active map areas, this limits the number of vmas * per mm struct. Users can overwrite this number by sysctl but there is a
Add three architecture overrideable function to test if the p4d, pud, or pmd layer of a page table is folded or not. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> --- include/linux/mm.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)