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Date:   Fri, 8 Aug 2014 22:47:05 +0200
From:   Ralf Baechle <ralf@linux-mips.org>
To:     David Daney <ddaney.cavm@gmail.com>
Cc:     Lars Persson <lars.persson@axis.com>, linux-mips@linux-mips.org,
        Lars Persson <larper@axis.com>
Subject: Re: [PATCH v2] MIPS: Remove race window in page fault handling
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On Fri, Aug 08, 2014 at 09:55:00AM -0700, David Daney wrote:

> >+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
> >+	pte_t *ptep, pte_t pteval);
> >+
> 
> Is it possible to reorder the code such that this declaration is not
> necessary?

That's not as obvious as one might think initially.  set_pte_at needs
to be defined after set_pte but before clear_pte which is calling set_pte_at.

Of both set_pte and clear_pte there are two #ifdefd variants.

set_pte_at is a fairly small function only but it's invoked quite a few
times so I was a little concerned about the effect on I'm experimenting with
outlining set_pte_at entirely.  ip22_defconfig with the patch applied as
posted; this is the effect on code size.

  text    data     bss     dec     hex filename
3790118  175304   84544 4049966  3dcc2e vmlinux		as posted
3789062	 175304	  84544	4048910	 3dc80e	vmlinux		set_pte_at outlined

  Ralf