Re: [PATCH 0/4] m68k/mm: Add missing initialization of max_pfn and {min,max}_low_pfn

Greg Ungerer
2015-11-17T00:17:43Z

Hi Geert,

On 15/11/15 21:04, Geert Uytterhoeven wrote:
> This patch series adds missing initialization of max_pfn, min_low_pfn,
> and max_low_pfn on various m68k platforms.
>
> This was exposed by failing selftests/vm/mlock2-tests.
>
> Note that several other architectures lack a proper initialization of
> max_pfn. On some of them it's completely missing, on others max_pfn is a
> local variable, hence it hides the global max_pfn, which is thus not
> initialized neither.
>
> On platforms with MMU, this can easily be verified by reading the
> following virtual files (CONFIG_PROC_PAGE_MONITOR=y):
>
> /proc/kpagecount
> /proc/kpageflags
> /proc/kpagecgroup (CONFIG_MEMCG=y)
>
> If max_pfn is not initialized, all three virtual files are empty.
>
> Besides the above, max_pfn is also used to calculate DMA masks for block
> devices. An uninitialized (zero) value means all RAM is suitable for
> DMA.

All looks good to me. Tested-by acks set separately. But otherwise

Acked-by: Greg Ungerer <gerg@uclinux.org>

Regards
Greg

> Absence of initialization of min_low_pfn and max_low_pfn is more subtle.
> (are there any bad side-effects?).
>
> Geert Uytterhoeven (4):
> m68k/mm: motorola - Add missing initialization of max_pfn
> m68k/mm: m54xx - Add missing initialization of max_pfn
> m68k/mm: sun3 - Add missing initialization of max_pfn and
> {min,max}_low_pfn
> m68knommu: Add missing initialization of max_pfn and {min,max}_low_pfn
>
> arch/m68k/coldfire/m54xx.c | 2 +-
> arch/m68k/kernel/setup_no.c | 9 ++++++---
> arch/m68k/mm/motorola.c | 2 +-
> arch/m68k/sun3/config.c | 4 ++--
> 4 files changed, 10 insertions(+), 7 deletions(-)
>