Re: [patch] mm, show_mem: suppress page counts in non-blockablecontexts

From: David Rientjes
Date: Wed Feb 27 2013 - 17:13:43 EST


On Wed, 27 Feb 2013, Dave Hansen wrote:

> On 02/26/2013 04:46 PM, David Rientjes wrote:
> > diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> > --- a/arch/arm/mm/init.c
> > +++ b/arch/arm/mm/init.c
> > @@ -99,6 +99,9 @@ void show_mem(unsigned int filter)
> > printk("Mem-info:\n");
> > show_free_areas(filter);
> >
> > + if (filter & SHOW_MEM_FILTER_PAGE_COUNT)
> > + return;
> > +
>
> Won't this just look like a funky truncated warning to the end user?
>

No, because of the uninhibited call to show_free_areas() above. This
still dumps the pcp state, global and per-node page type breakdown, and
free pages at given order. The only things suppresses are the total
pages, pages reserved, pages shared, and pages non-shared counts that are
quite expensive to determine because it walks all memory while irqs are
disabled and increases with the amount of RAM a system has.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/