Re: [PATCH RFC 4/7] riscv/vdso: don't clear PG_reserved

Palmer Dabbelt
2018-12-07T18:45:13Z

On Wed, 05 Dec 2018 04:28:48 PST (-0800), david@redhat.com wrote:
> The VDSO is part of the kernel image and therefore the struct pages are
> marked as reserved during boot.
>
> As we install a special mapping, the actual struct pages will never be
> exposed to MM via the page tables. We can therefore leave the pages
> marked as reserved.
>
> Cc: Palmer Dabbelt <palmer@sifive.com>
> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: Tobias Klauser <tklauser@distanz.ch>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Matthew Wilcox <willy@infradead.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> arch/riscv/kernel/vdso.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
> index 582cb153eb24..0cd044122234 100644
> --- a/arch/riscv/kernel/vdso.c
> +++ b/arch/riscv/kernel/vdso.c
> @@ -54,7 +54,6 @@ static int __init vdso_init(void)
> struct page *pg;
>
> pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
> - ClearPageReserved(pg);
> vdso_pagelist[i] = pg;
> }
> vdso_pagelist[i] = virt_to_page(vdso_data);

I'm going to assume this will go in through another tree along with the rest of
the set assuming everyone else is happy with it.

Acked-by: Palmer Dabbelt <palmer@sifive.com>

Thanks!