Re: [PATCH 4/6] x86/kasan: Prepare clear_pgds() to switch to <asm-generic/pgtable-nop4d.h>

From	"Kirill A. Shutemov" <kirill@shutemov.name>
Newsgroups	linux.kernel
Subject	Re: [PATCH 4/6] x86/kasan: Prepare clear_pgds() to switch to <asm-generic/pgtable-nop4d.h>
Date	2017-03-24 10:10 +0100
Message-ID	<totom-7Is-11@gated-at.bofh.it> (permalink)
References	<tm5gu-2nQ-21@gated-at.bofh.it> <tm62S-2ZV-21@gated-at.bofh.it> <tnJ2a-7gq-11@gated-at.bofh.it> <tnJ2a-7gq-9@gated-at.bofh.it>
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On Wed, Mar 22, 2017 at 08:31:36AM +0100, Ingo Molnar wrote:
> * Andrey Ryabinin <aryabinin@virtuozzo.com> wrote:
> > On 03/17/2017 09:55 PM, Kirill A. Shutemov wrote:
> > > With folded p4d, pgd_clear() is nop. Change clear_pgds() to use
> > > p4d_clear() instead.
> > > 
> > 
> > You could probably just use set_pgd(pgd_offset_k(start), __pgd(0)); instead of pgd_clear()
> > as we already do in arm64.
> > It's basically pgd_clear() except it's not a nop wih p4d folded.
> 
> Makes sense. Kirill, if you agree, mind spinning a v2 patch?

I can re-spin, if you want. But honestly, I don't think such constructs
help readability.

-- 
 Kirill A. Shutemov

Thread

[PATCH 0/6] x86: 5-level paging enabling for v4.12, Part 2 "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-17 20:00 +0100
  [PATCH 6/6] x86: Convert the rest of the code to support p4d_t "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-17 20:00 +0100
    [tip:x86/mm] x86: Convert the rest of the code to support p4d_t "tip-bot for Kirill A. Shutemov" <tipbot@zytor.com> - 2017-03-27 12:40 +0200
  [PATCH 2/6] x86/efi: Add 5-level paging support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-17 20:00 +0100
    [tip:x86/mm] x86/efi: Add 5-level paging support "tip-bot for Kirill A. Shutemov" <tipbot@zytor.com> - 2017-03-27 12:40 +0200
  [PATCH 1/6] x86/kexec: Add 5-level paging support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-17 20:00 +0100
    [tip:x86/mm] x86/kexec: Add 5-level paging support "tip-bot for Kirill A. Shutemov" <tipbot@zytor.com> - 2017-03-27 12:40 +0200
  [PATCH 5/6] x86/xen: Change __xen_pgd_walk() and xen_cleanmfnmap() to support p4d "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-17 20:00 +0100
    Re: [PATCH 5/6] x86/xen: Change __xen_pgd_walk() and  xen_cleanmfnmap() to support p4d Ingo Molnar <mingo@kernel.org> - 2017-03-27 08:40 +0200
      Re: [PATCH 5/6] x86/xen: Change __xen_pgd_walk() and  xen_cleanmfnmap() to support p4d "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-03-27 15:20 +0200
    [tip:x86/mm] x86/xen: Change __xen_pgd_walk() and xen_cleanmfnmap()  to support p4d tip-bot for Xiong Zhang <tipbot@zytor.com> - 2017-03-27 12:40 +0200
  [PATCH 4/6] x86/kasan: Prepare clear_pgds() to switch to <asm-generic/pgtable-nop4d.h> "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-03-17 20:50 +0100
    Re: [PATCH 4/6] x86/kasan: Prepare clear_pgds() to switch to  <asm-generic/pgtable-nop4d.h> Ingo Molnar <mingo@kernel.org> - 2017-03-22 08:40 +0100
      Re: [PATCH 4/6] x86/kasan: Prepare clear_pgds() to switch to  <asm-generic/pgtable-nop4d.h> "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-03-24 10:10 +0100
        Re: [PATCH 4/6] x86/kasan: Prepare clear_pgds() to switch to  <asm-generic/pgtable-nop4d.h> Ingo Molnar <mingo@kernel.org> - 2017-03-24 12:00 +0100
    [tip:x86/mm] x86/kasan: Prepare clear_pgds() to switch to  <asm-generic/pgtable-nop4d.h> "tip-bot for Kirill A. Shutemov" <tipbot@zytor.com> - 2017-03-27 12:40 +0200

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