Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late()

From	Linus Torvalds <torvalds@linux-foundation.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late()
Date	2015-09-22 20:50 +0200
Message-ID	<qbANC-5hQ-69@gated-at.bofh.it> (permalink)
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On Tue, Sep 22, 2015 at 11:37 AM, Andy Lutomirski <luto@amacapital.net> wrote:
> kinds of mess.
>
> I don't think that anyone really wants to move #PF to IST, which means
> that we simply cannot handle vmalloc faults that happen when switching
> stacks after SYSCALL, no matter what fanciness we shove into the
> page_fault asm.

But that's fine. The kernel stack is special.  So yes, we want to make
sure that the kernel stack is always mapped in the thread whose stack
it is.

But that's not a big and onerous guarantee to make. Not when the
*real* problem is "random vmalloc allocations made by other processes
that we are not in the least interested in, and we don't want to add
synchronization for".

                         Linus
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Thread

Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late() Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-22 20:00 +0200
  Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late() Andy Lutomirski <luto@amacapital.net> - 2015-09-22 20:10 +0200
    Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late() Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-22 20:30 +0200
      Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late() Andy Lutomirski <luto@amacapital.net> - 2015-09-22 20:40 +0200
        Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late() Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-22 20:50 +0200
          Re: [PATCH 05/11] mm: Introduce arch_pgd_init_late() Andy Lutomirski <luto@amacapital.net> - 2015-09-22 21:00 +0200

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