From: Balbir Singh <bsingharora@gmail.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, dave.hansen@intel.com,
aneesh.kumar@linux.vnet.ibm.com, mpe@ellerman.id.au
Subject: Re: [PATCH 05/10] powerpc/hugetlb: Split the function 'huge_pte_alloc'
Date: Mon, 11 Apr 2016 23:51:20 +1000 [thread overview]
Message-ID: <570BABD8.5080703@gmail.com> (raw)
In-Reply-To: <1460007464-26726-6-git-send-email-khandual@linux.vnet.ibm.com>
On 07/04/16 15:37, Anshuman Khandual wrote:
> Currently the function 'huge_pte_alloc' has got two versions, one for the
> BOOK3S server and the other one for the BOOK3E embedded platforms. This
> change splits only the BOOK3S server version into two parts, one for the
> ARCH_WANT_GENERAL_HUGETLB config implementation and the other one for
> everything else. This change is one of the prerequisites towards enabling
> ARCH_WANT_GENERAL_HUGETLB config option on POWER platform.
>
> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> ---
> arch/powerpc/mm/hugetlbpage.c | 67 +++++++++++++++++++++++++++----------------
> 1 file changed, 43 insertions(+), 24 deletions(-)
>
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index d991b9e..e453918 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -59,6 +59,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
> return __find_linux_pte_or_hugepte(mm->pgd, addr, NULL, NULL);
> }
>
> +#ifndef CONFIG_ARCH_WANT_GENERAL_HUGETLB
> static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
> unsigned long address, unsigned pdshift, unsigned pshift)
> {
> @@ -116,6 +117,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
> spin_unlock(&mm->page_table_lock);
> return 0;
> }
> +#endif /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */
>
> /*
> * These macros define how to determine which level of the page table holds
> @@ -130,6 +132,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
> #endif
>
> #ifdef CONFIG_PPC_BOOK3S_64
> +#ifndef CONFIG_ARCH_WANT_GENERAL_HUGETLB
> /*
> * At this point we do the placement change only for BOOK3S 64. This would
> * possibly work on other subarchs.
> @@ -145,32 +148,23 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
>
> addr &= ~(sz-1);
> pg = pgd_offset(mm, addr);
> -
> - if (pshift == PGDIR_SHIFT)
> - /* 16GB huge page */
> - return (pte_t *) pg;
> - else if (pshift > PUD_SHIFT)
> - /*
> - * We need to use hugepd table
> - */
> + if (pshift > PUD_SHIFT) {
> hpdp = (hugepd_t *)pg;
> - else {
> - pdshift = PUD_SHIFT;
> - pu = pud_alloc(mm, pg, addr);
> - if (pshift == PUD_SHIFT)
> - return (pte_t *)pu;
> - else if (pshift > PMD_SHIFT)
> - hpdp = (hugepd_t *)pu;
> - else {
> - pdshift = PMD_SHIFT;
> - pm = pmd_alloc(mm, pu, addr);
> - if (pshift == PMD_SHIFT)
> - /* 16MB hugepage */
> - return (pte_t *)pm;
> - else
> - hpdp = (hugepd_t *)pm;
> - }
> + goto hugepd_search;
> }
> +
> + pdshift = PUD_SHIFT;
> + pu = pud_alloc(mm, pg, addr);
> + if (pshift > PMD_SHIFT) {
> + hpdp = (hugepd_t *)pu;
> + goto hugepd_search;
> + }
> +
> + pdshift = PMD_SHIFT;
> + pm = pmd_alloc(mm, pu, addr);
> + hpdp = (hugepd_t *)pm;
> +
> +hugepd_search:
> if (!hpdp)
> return NULL;
>
> @@ -182,6 +176,31 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
> return hugepte_offset(*hpdp, addr, pdshift);
> }
>
> +#else /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
> +pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
This is confusing, aren't we using the one from mm/hugetlb.c?
> +{
> + pgd_t *pg;
> + pud_t *pu;
> + pmd_t *pm;
> + unsigned pshift = __ffs(sz);
> +
> + addr &= ~(sz-1);
Am I reading this right? Shouldn't this be addr &= ~(1 << pshift - 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 /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */
> #else
>
> pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
>
next prev parent reply other threads:[~2016-04-11 13:51 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-07 5:37 [PATCH 00/10] Enable HugeTLB page migration on POWER Anshuman Khandual
2016-04-07 5:37 ` [PATCH 01/10] mm/mmap: Replace SHM_HUGE_MASK with MAP_HUGE_MASK inside mmap_pgoff Anshuman Khandual
2016-04-07 8:28 ` Balbir Singh
2016-04-13 7:54 ` Michal Hocko
2016-04-07 5:37 ` [PATCH 02/10] mm/hugetlb: Add PGD based implementation awareness Anshuman Khandual
2016-04-07 9:04 ` Balbir Singh
2016-04-11 5:25 ` Anshuman Khandual
2016-04-11 6:10 ` Anshuman Khandual
2016-04-07 5:37 ` [PATCH 03/10] mm/hugetlb: Protect follow_huge_(pud|pgd) functions from race Anshuman Khandual
2016-04-07 9:16 ` kbuild test robot
2016-04-18 8:44 ` Anshuman Khandual
2016-04-07 9:26 ` Balbir Singh
2016-04-11 5:39 ` Anshuman Khandual
2016-04-11 12:46 ` Balbir Singh
2016-04-07 9:34 ` kbuild test robot
2016-04-11 6:04 ` Anshuman Khandual
2016-04-18 8:42 ` Anshuman Khandual
2016-04-07 5:37 ` [PATCH 04/10] powerpc/hugetlb: Add ABI defines for MAP_HUGE_16MB and MAP_HUGE_16GB Anshuman Khandual
2016-04-07 5:37 ` [PATCH 05/10] powerpc/hugetlb: Split the function 'huge_pte_alloc' Anshuman Khandual
2016-04-11 13:51 ` Balbir Singh [this message]
2016-04-13 11:08 ` Anshuman Khandual
2016-04-07 5:37 ` [PATCH 06/10] powerpc/hugetlb: Split the function 'huge_pte_offset' Anshuman Khandual
2016-04-07 5:37 ` [PATCH 07/10] powerpc/hugetlb: Prepare arch functions for ARCH_WANT_GENERAL_HUGETLB Anshuman Khandual
2016-04-07 5:37 ` [PATCH 08/10] powerpc/hugetlb: Selectively enable ARCH_WANT_GENERAL_HUGETLB Anshuman Khandual
2016-04-07 5:37 ` [PATCH 09/10] powerpc/hugetlb: Selectively enable ARCH_ENABLE_HUGEPAGE_MIGRATION Anshuman Khandual
2016-04-07 5:37 ` [PATCH 10/10] selfttest/powerpc: Add memory page migration tests Anshuman Khandual
2016-04-18 8:52 ` [PATCH 00/10] Enable HugeTLB page migration on POWER Anshuman Khandual
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=570BABD8.5080703@gmail.com \
--to=bsingharora@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=dave.hansen@intel.com \
--cc=hughd@google.com \
--cc=khandual@linux.vnet.ibm.com \
--cc=kirill@shutemov.name \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mgorman@techsingularity.net \
--cc=mpe@ellerman.id.au \
--cc=n-horiguchi@ah.jp.nec.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).