Re: [PATCH 2/2] Documentation: clarify in calculating zone protection

From: Yaowei Bai
Date: Wed Aug 26 2015 - 10:50:17 EST


On Tue, Aug 25, 2015 at 05:06:33PM +0200, Michal Hocko wrote:
> On Tue 25-08-15 22:01:31, Yaowei Bai wrote:
> > Every zone's protection is calculated from managed_pages not
> > present_pages, to avoid misleading, correct it.
>
> This can be folded in to your previous patch
> http://marc.info/?l=linux-mm&m=144023106610358&w=2

OK, thanks.

>
> >
> > Signed-off-by: Yaowei Bai <bywxiaobai@xxxxxxx>
> > ---
> > Documentation/sysctl/vm.txt | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
> > index 9832ec5..1739b31 100644
> > --- a/Documentation/sysctl/vm.txt
> > +++ b/Documentation/sysctl/vm.txt
> > @@ -349,7 +349,7 @@ zone[i]'s protection[j] is calculated by following expression.
> >
> > (i < j):
> > zone[i]->protection[j]
> > - = (total sums of present_pages from zone[i+1] to zone[j] on the node)
> > + = (total sums of managed_pages from zone[i+1] to zone[j] on the node)
> > / lowmem_reserve_ratio[i];
> > (i = j):
> > (should not be protected. = 0;
> > @@ -360,7 +360,7 @@ The default values of lowmem_reserve_ratio[i] are
> > 256 (if zone[i] means DMA or DMA32 zone)
> > 32 (others).
> > As above expression, they are reciprocal number of ratio.
> > -256 means 1/256. # of protection pages becomes about "0.39%" of total present
> > +256 means 1/256. # of protection pages becomes about "0.39%" of total managed
> > pages of higher zones on the node.
> >
> > If you would like to protect more pages, smaller values are effective.
> > --
> > 1.9.1
> >
> >
> > --
> > 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/
>
> --
> Michal Hocko
> SUSE Labs

--
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/