+CC linux-api

On 08/28/2017 02:28 AM, Joonsoo Kim wrote:

On Fri, Aug 25, 2017 at 09:56:10AM +0200, Vlastimil Babka wrote:

quoted

On 08/25/2017 02:20 AM, Joonsoo Kim wrote:

quoted

On Thu, Aug 24, 2017 at 11:41:58AM +0200, Vlastimil Babka wrote:

Hmm, this is already pointed by Minchan and I have answered that.

lkml.kernel.org/r/<20170421013243.GA13966@js1304-desktop>

If you have a better idea, please let me know.

My idea is that size of sysctl_lowmem_reserve_ratio is ZONE_NORMAL+1 and
it has no entries for zones > NORMAL. The
setup_per_zone_lowmem_reserve() is adjusted to only set
lower_zone->lowmem_reserve[j] for idx <= ZONE_NORMAL.

I can't imagine somebody would want override the ratio for HIGHMEM or
MOVABLE
(where it has no effect anyway) so the simplest thing is not to expose
it at all.

Seems reasonable. However, if there is a user who checks
sysctl_lowmem_reserve_ratio entry for HIGHMEM and change it, suggested
interface will cause a problem since it doesn't expose ratio for
HIGHMEM. Am I missing something?

As you explained, it makes little sense to change it for HIGHMEM which
only affects MOVABLE allocations. Also I doubt there are many systems
with both HIGHMEM (implies 32bit) *and* MOVABLE (implies NUMA, memory
hotplug...) zones. So I would just remove it, and if somebody will
really miss it, we can always add it back. In any case, please CC
linux-api on the next version.

Thanks.

quoted

quoted

Thanks.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>