From: Rui Teng <rui.teng@linux.vnet.ibm.com>
To: Anshuman Khandual <khandual@linux.vnet.ibm.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Cc: hughd@google.com, kirill@shutemov.name,
n-horiguchi@ah.jp.nec.com, akpm@linux-foundation.org,
mgorman@techsingularity.net, aneesh.kumar@linux.vnet.ibm.com,
mpe@ellerman.id.au
Subject: Re: [RFC 6/9] powerpc/hugetlb: Enable ARCH_WANT_GENERAL_HUGETLB for BOOK3S 64K
Date: Mon, 21 Mar 2016 17:55:26 +0800 [thread overview]
Message-ID: <56EFC50E.6090901@linux.vnet.ibm.com> (raw)
In-Reply-To: <1457525450-4262-6-git-send-email-khandual@linux.vnet.ibm.com>
On 3/9/16 8:10 PM, Anshuman Khandual wrote:
> This enables ARCH_WANT_GENERAL_HUGETLB for BOOK3S 64K in Kconfig.
> It also implements a new function 'pte_huge' which is required by
> function 'huge_pte_alloc' from generic VM. Existing BOOK3S 64K
> specific functions 'huge_pte_alloc' and 'huge_pte_offset' (which
> are no longer required) are removed with this change.
>
> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> ---
> arch/powerpc/Kconfig | 4 ++
> arch/powerpc/include/asm/book3s/64/hash-64k.h | 8 ++++
> arch/powerpc/mm/hugetlbpage.c | 60 ---------------------------
> 3 files changed, 12 insertions(+), 60 deletions(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 9faa18c..c6920bb 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -33,6 +33,10 @@ config HAVE_SETUP_PER_CPU_AREA
> config NEED_PER_CPU_EMBED_FIRST_CHUNK
> def_bool PPC64
>
> +config ARCH_WANT_GENERAL_HUGETLB
> + depends on PPC_64K_PAGES && PPC_BOOK3S_64
> + def_bool y
> +
On the source code, the PowerPC specified huge_pte_alloc() function will
not be defined if the configure logic is "!PPC_4K_PAGES &&
PPC_BOOK3S_64", but on the Kconfig file the general huge_pte_alloc()
function will only be defined if the logic is "PPC_64K_PAGES &&
PPC_BOOK3S_64".
It works if PPC_4K_PAGES and PPC_64K_PAGES always against each other,
but I also find PPC_16K_PAGES and PPC_256K_PAGES on the same Kconfig
file. What happens if we configure PPC_16K_PAGES instead of PPC_4K_PAGES?
> config NR_IRQS
> int "Number of virtual interrupt numbers"
> range 32 32768
> diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
> index 849bbec..5e9b9b9 100644
> --- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
> +++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
> @@ -143,6 +143,14 @@ extern bool __rpte_sub_valid(real_pte_t rpte, unsigned long index);
> * Defined in such a way that we can optimize away code block at build time
> * if CONFIG_HUGETLB_PAGE=n.
> */
> +static inline int pte_huge(pte_t pte)
> +{
> + /*
> + * leaf pte for huge page
> + */
> + return !!(pte_val(pte) & _PAGE_PTE);
> +}
> +
> static inline int pmd_huge(pmd_t pmd)
> {
> /*
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index f834a74..f6e4712 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -59,42 +59,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
> /* Only called for hugetlbfs pages, hence can ignore THP */
> return __find_linux_pte_or_hugepte(mm->pgd, addr, NULL, NULL);
> }
> -#else
> -pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
> -{
> - pgd_t pgd, *pgdp;
> - pud_t pud, *pudp;
> - pmd_t pmd, *pmdp;
> -
> - pgdp = mm->pgd + pgd_index(addr);
> - pgd = READ_ONCE(*pgdp);
> -
> - if (pgd_none(pgd))
> - return NULL;
> -
> - if (pgd_huge(pgd))
> - return (pte_t *)pgdp;
> -
> - pudp = pud_offset(&pgd, addr);
> - pud = READ_ONCE(*pudp);
> - if (pud_none(pud))
> - return NULL;
> -
> - if (pud_huge(pud))
> - return (pte_t *)pudp;
>
> - pmdp = pmd_offset(&pud, addr);
> - pmd = READ_ONCE(*pmdp);
> - if (pmd_none(pmd))
> - return NULL;
> -
> - if (pmd_huge(pmd))
> - return (pte_t *)pmdp;
> - return NULL;
> -}
> -#endif /* !defined(CONFIG_PPC_64K_PAGES) || !defined(CONFIG_PPC_BOOK3S_64) */
> -
> -#if !defined(CONFIG_PPC_64K_PAGES) || !defined(CONFIG_PPC_BOOK3S_64)
> static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
> unsigned long address, unsigned pdshift, unsigned pshift)
> {
> @@ -211,31 +176,6 @@ hugepd_search:
>
> return hugepte_offset(*hpdp, addr, pdshift);
> }
> -
> -#else
> -pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
> -{
> - pgd_t *pg;
> - pud_t *pu;
> - pmd_t *pm;
> - unsigned pshift = __ffs(sz);
> -
> - addr &= ~(sz-1);
> - pg = pgd_offset(mm, addr);
> -
> - if (pshift == PGDIR_SHIFT) /* 16GB Huge Page */
> - return (pte_t *)pg;
> -
> - pu = pud_alloc(mm, pg, addr); /* NA, skipped */
> - if (pshift == PUD_SHIFT)
> - return (pte_t *)pu;
> -
> - pm = pmd_alloc(mm, pu, addr); /* 16MB Huge Page */
> - if (pshift == PMD_SHIFT)
> - return (pte_t *)pm;
> -
> - return NULL;
> -}
> #endif
> #else
>
Why these code need to be added on patch 4/9 but removed on 6/9?
next prev parent reply other threads:[~2016-03-21 9:55 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-09 12:10 [RFC 1/9] mm/hugetlb: Make GENERAL_HUGETLB functions PGD implementation aware Anshuman Khandual
2016-03-09 12:10 ` [RFC 2/9] mm/hugetlb: Add follow_huge_pgd function Anshuman Khandual
2016-03-11 3:02 ` Anshuman Khandual
2016-03-09 12:10 ` [RFC 3/9] mm/gup: Make follow_page_mask function PGD implementation aware Anshuman Khandual
2016-03-11 3:03 ` Anshuman Khandual
2016-03-09 12:10 ` [RFC 4/9] powerpc/mm: Split huge_pte_alloc function for BOOK3S 64K Anshuman Khandual
2016-03-09 19:55 ` Aneesh Kumar K.V
2016-03-10 5:33 ` Anshuman Khandual
2016-03-09 12:10 ` [RFC 5/9] powerpc/mm: Split huge_pte_offset " Anshuman Khandual
2016-03-09 22:57 ` Dave Hansen
2016-03-10 3:37 ` Anshuman Khandual
2016-03-09 12:10 ` [RFC 6/9] powerpc/hugetlb: Enable ARCH_WANT_GENERAL_HUGETLB " Anshuman Khandual
2016-03-09 19:58 ` Aneesh Kumar K.V
2016-03-10 5:12 ` Anshuman Khandual
2016-03-21 9:55 ` Rui Teng [this message]
2016-03-09 12:10 ` [RFC 7/9] powerpc/hugetlb: Change follow_huge_* routines " Anshuman Khandual
2016-03-09 12:10 ` [RFC 8/9] powerpc/mm: Enable HugeTLB page migration Anshuman Khandual
2016-03-09 12:10 ` [RFC 9/9] selfttest/powerpc: Add memory page migration tests Anshuman Khandual
2016-03-09 20:01 ` Aneesh Kumar K.V
2016-03-10 5:05 ` Anshuman Khandual
2016-03-11 3:01 ` [RFC 1/9] mm/hugetlb: Make GENERAL_HUGETLB functions PGD implementation aware Anshuman Khandual
2016-03-14 20:29 ` Andrew Morton
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