Re: [PATCH 12/15] powerpc/nohash/64: switch to generic version of pte allocation
On Thu, May 02, 2019 at 06:56:07PM +0200, Christophe Leroy wrote:
>
>
> Le 02/05/2019 à 17:28, Mike Rapoport a écrit :
> >The 64-bit book-E powerpc implements pte_alloc_one(),
> >pte_alloc_one_kernel(), pte_free_kernel() and pte_free() the same way as
> >the generic version.
>
> Will soon be converted to the same as the 3 other PPC subarches, see
> https://patchwork.ozlabs.org/patch/1091590/
Thanks for the heads up. I'll drop this from the next re-spin.
> Christophe
>
> >
> >Switch it to the generic version that does exactly the same thing.
> >
> >Signed-off-by: Mike Rapoport
> >---
> > arch/powerpc/include/asm/nohash/64/pgalloc.h | 35
> > ++--
> > 1 file changed, 2 insertions(+), 33 deletions(-)
> >
> >diff --git a/arch/powerpc/include/asm/nohash/64/pgalloc.h
> >b/arch/powerpc/include/asm/nohash/64/pgalloc.h
> >index 66d086f..bfb53a0 100644
> >--- a/arch/powerpc/include/asm/nohash/64/pgalloc.h
> >+++ b/arch/powerpc/include/asm/nohash/64/pgalloc.h
> >@@ -11,6 +11,8 @@
> > #include
> > #include
> >+#include /* for pte_{alloc,free}_one */
> >+
> > struct vmemmap_backing {
> > struct vmemmap_backing *list;
> > unsigned long phys;
> >@@ -92,39 +94,6 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t
> >*pmd)
> > kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), pmd);
> > }
> >-
> >-static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> >-{
> >-return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
> >-}
> >-
> >-static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
> >-{
> >-struct page *page;
> >-pte_t *pte;
> >-
> >-pte = (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT);
> >-if (!pte)
> >-return NULL;
> >-page = virt_to_page(pte);
> >-if (!pgtable_page_ctor(page)) {
> >-__free_page(page);
> >-return NULL;
> >-}
> >-return page;
> >-}
> >-
> >-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> >-{
> >-free_page((unsigned long)pte);
> >-}
> >-
> >-static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
> >-{
> >-pgtable_page_dtor(ptepage);
> >-__free_page(ptepage);
> >-}
> >-
> > static inline void pgtable_free(void *table, int shift)
> > {
> > if (!shift) {
> >
>
--
Sincerely yours,
Mike.
Re: [PATCH 04/15] arm64: switch to generic version of pte allocation
On Fri, May 03, 2019 at 11:05:09AM +0100, Mark Rutland wrote:
> Hi,
>
> On Thu, May 02, 2019 at 06:28:31PM +0300, Mike Rapoport wrote:
> > The PTE allocations in arm64 are identical to the generic ones modulo the
> > GFP flags.
> >
> > Using the generic pte_alloc_one() functions ensures that the user page
> > tables are allocated with __GFP_ACCOUNT set.
> >
> > The arm64 definition of PGALLOC_GFP is removed and replaced with
> > GFP_PGTABLE_USER for p[gum]d_alloc_one() and for KVM memory cache.
> >
> > The mappings created with create_pgd_mapping() are now using
> > GFP_PGTABLE_KERNEL.
> >
> > The conversion to the generic version of pte_free_kernel() removes the NULL
> > check for pte.
> >
> > The pte_free() version on arm64 is identical to the generic one and
> > can be simply dropped.
> >
> > Signed-off-by: Mike Rapoport
> > ---
> > arch/arm64/include/asm/pgalloc.h | 43
> >
> > arch/arm64/mm/mmu.c | 2 +-
> > arch/arm64/mm/pgd.c | 4 ++--
> > virt/kvm/arm/mmu.c | 2 +-
> > 4 files changed, 8 insertions(+), 43 deletions(-)
>
> [...]
>
> > diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c
> > index 289f911..2ef1a53 100644
> > --- a/arch/arm64/mm/pgd.c
> > +++ b/arch/arm64/mm/pgd.c
> > @@ -31,9 +31,9 @@ static struct kmem_cache *pgd_cache __ro_after_init;
> > pgd_t *pgd_alloc(struct mm_struct *mm)
> > {
> > if (PGD_SIZE == PAGE_SIZE)
> > - return (pgd_t *)__get_free_page(PGALLOC_GFP);
> > + return (pgd_t *)__get_free_page(GFP_PGTABLE_USER);
> > else
> > - return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
> > + return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_USER);
> > }
>
> In efi_virtmap_init() we use pgd_alloc() to allocate a pgd for EFI
> runtime services, which we map with a special kernel page table.
>
> I'm not sure if accounting that is problematic, as it's allocated in a
> kernel thread off the back of an early_initcall.
The accounting bypasses kernel threads so there should be no problem.
> Just to check, Is that sound, or do we need a pgd_alloc_kernel()?
>
> Thanks,
> Mark.
>
--
Sincerely yours,
Mike.
Re: [PATCH 08/15] mips: switch to generic version of pte allocation
On Thu, May 02, 2019 at 07:09:47PM +, Paul Burton wrote: > Hi Mike, > > On Thu, May 02, 2019 at 06:28:35PM +0300, Mike Rapoport wrote: > > MIPS allocates kernel PTE pages with > > > > __get_free_pages(GFP_KERNEL | __GFP_ZERO, PTE_ORDER) > > > > and user PTE pages with > > > > alloc_pages(GFP_KERNEL | __GFP_ZERO, PTE_ORDER) > > That bit isn't quite true - we don't use __GFP_ZERO in pte_alloc_one() & > instead call clear_highpage() on the allocated page. Not that I have a > problem with using __GFP_ZERO - it seems like the more optimal choice. > It just might be worth mentioning the change & expected equivalent > behavior. You are right, I'll fix the changelog. > Otherwise: > > Acked-by: Paul Burton Thanks. > Thanks, > Paul > -- Sincerely yours, Mike.
Re: [PATCH 01/15] asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]
On Thu, May 02, 2019 at 07:03:11PM +, Paul Burton wrote:
> Hi Mike,
>
> On Thu, May 02, 2019 at 06:28:28PM +0300, Mike Rapoport wrote:
> > +/**
> > + * pte_free_kernel - free PTE-level user page table page
> > + * @mm: the mm_struct of the current context
> > + * @pte_page: the `struct page` representing the page table
> > + */
> > +static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
> > +{
> > + pgtable_page_dtor(pte_page);
> > + __free_page(pte_page);
> > +}
>
> Nit: the comment names the wrong function (s/pte_free_kernel/pte_free/).
Argh, evil copy-paste :)
Thanks!
> Thanks,
> Paul
>
--
Sincerely yours,
Mike.
