Messages in this thread |  | | Date | Thu, 13 Feb 2014 11:10:28 -0500 | From | Rik van Riel <> | Subject | Re: [PATCH 1/2] mm/vmscan: restore sc->gfp_mask after promoting it to __GFP_HIGHMEM |
| |
On 02/12/2014 09:39 PM, Weijie Yang wrote:
> --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2298,14 +2298,17 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) > unsigned long nr_soft_reclaimed; > unsigned long nr_soft_scanned; > bool aborted_reclaim = false; > + bool promoted_mask = false; > > /* > * If the number of buffer_heads in the machine exceeds the maximum > * allowed level, force direct reclaim to scan the highmem zone as > * highmem pages could be pinning lowmem pages storing buffer_heads > */ > - if (buffer_heads_over_limit) > + if (buffer_heads_over_limit) {
It took me a minute to figure out why you are doing things this way, so maybe this could use a comment, or maybe it could be done in a simpler way, by simply saving and restoring the original mask?
orig_mask = sc->gfp_mask;
> + promoted_mask = !(sc->gfp_mask & __GFP_HIGHMEM); > sc->gfp_mask |= __GFP_HIGHMEM; > + } > > for_each_zone_zonelist_nodemask(zone, z, zonelist, > gfp_zone(sc->gfp_mask), sc->nodemask) { > @@ -2354,6 +2357,9 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) > shrink_zone(zone, sc); > } > > + if (promoted_mask) sc->gfp_mask = orig_mask;
> + sc->gfp_mask &= ~__GFP_HIGHMEM; > + > return aborted_reclaim; > } > >
-- All rights reversed
|  |