linux-kernel - Re: [PATCH 2/2] sh: add support for folded p4d page tables

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Date:   Tue, 17 Dec 2019 20:32:14 +0200
From:   Mike Rapoport <rppt@...nel.org>
To:     Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     Linux-sh list <linux-sh@...r.kernel.org>,
        Yoshinori Sato <ysato@...rs.sourceforge.jp>,
        Rich Felker <dalias@...c.org>, Linux MM <linux-mm@...ck.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Mike Rapoport <rppt@...ux.ibm.com>
Subject: Re: [PATCH 2/2] sh: add support for folded p4d page tables

On Tue, Dec 17, 2019 at 06:59:43PM +0100, Geert Uytterhoeven wrote:
> Hi Mike,
> 
> On Tue, Dec 17, 2019 at 3:23 PM Mike Rapoport <rppt@...nel.org> wrote:
> > From: Mike Rapoport <rppt@...ux.ibm.com>
> >
> > Implement primitives necessary for the 4th level folding, add walks of p4d
> > level where appropriate and remove usage of __ARCH_USE_5LEVEL_HACK.
> >
> > Signed-off-by: Mike Rapoport <rppt@...ux.ibm.com>
> 
> Thanks for your patch!
> 
> > --- a/arch/sh/mm/fault.c
> > +++ b/arch/sh/mm/fault.c
> > @@ -65,7 +66,20 @@ static void show_pte(struct mm_struct *mm, unsigned long addr)
> >                         break;
> >                 }
> >
> > -               pud = pud_offset(pgd, addr);
> > +               p4d = p4d_offset(pgd, addr);
> > +               if (PTRS_PER_P4D != 1)
> > +                       printk(", *p4d=%0*Lx", (u32)(sizeof(*p4d) * 2),
> > +                              (u64)p4d_val(*p4d));
> 
> This (and the prints below) is gonna cause lots of broken output lines.
> You should use pr_cont() instead, and probably rebase on top of  my
> "[PATCH 7/7] sh: fault: Modernize printing of kernel messages"
> (https://lore.kernel.org/lkml/20191203162645.19950-8-geert+renesas@glider.be/).

Ok, will fix.	 

> > +
> > +               if (p4d_none(*p4d))
> > +                       break;
> > +
> > +               if (p4d_bad(*p4d)) {
> > +                       printk("(bad)");
> > +                       break;
> > +               }
> > +
> > +               pud = pud_offset(p4d, addr);
> >                 if (PTRS_PER_PUD != 1)
> >                         printk(", *pud=%0*Lx", (u32)(sizeof(*pud) * 2),
> >                                (u64)pud_val(*pud));
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

-- 
Sincerely yours,
Mike.