Re: [discuss] Re: [PATCH][Fix][Resend] Fix Bug #4959: Page tables corrupted during resume on x86-64 (take 3)

[Andi Kleen <ak@suse.de>]

On Wednesday 28 September 2005 22:24, Rafael J. Wysocki wrote:
> Hi,
>
> On Wednesday, 28 of September 2005 21:18, Andi Kleen wrote:
> > On Wednesday 28 September 2005 16:24, Rafael J. Wysocki wrote:
> > > Hi,
> > >
> > > The following patch fixes Bug #4959.  For this purpose it creates
> > > temporary page translation tables including the kernel mapping (reused)
> > > and the direct mapping (created from scratch) and makes swsusp switch
> > > to these tables right before the image is restored.
> > >
> > > The code that generates the direct mapping is based on the code in
> > > arch/x86_64/mm/init.c.
> >
> > Looks much better than before, but is there any reason you cannot
> > share the code with the mm/init.c code?
>
> I think so.  I have to make the temporary page tables nosavedata or set
> PG_nosave on them, so that swsusp doesn't overwrite them.  I'm not
> sure if I could do this cleanly if I used the code from mm/init.c directly.

Just pass a flag for that.

>
> > Also Suresh S. has a patch out to turn the initial page tables
> > into initdata. It'll probably conflict with that. Needs to be coordinated
> > with him.
>
> Do you mean the patch at:
> http://www.x86-64.org/lists/discuss/msg07297.html ?
> Unfortunately it interferes with the current swsusp code, which uses
> init_level4_pgt anyway.
>
> Could we please treat my patch as a (very much needed) urgent bugfix
> and make the whole swsusp code in line with the Suresh's patch later on?
>
> Suresh, could you please say what you think of it?

Suresh's patch is a urgent bug fix too. I suggest you two figure out how
to merge them.

-Andi