On Thu, 20 Aug 2015 03:28:05 -0400 Changsheng Liu <[email protected]> wrote:
> From: Changsheng Liu <[email protected]> > > When memory is hot added, should_add_memory_movable() always returns 0 > because the movable zone is empty, so the memory that was hot added will > add to the normal zone even if we want to remove the memory. > > So we change should_add_memory_movable(): if the user config > CONFIG_MOVABLE_NODE it will return 1 when the movable zone is empty. > > Reviewed-by: Andrew Morton <[email protected]> > Signed-off-by: Changsheng Liu <[email protected]> > Tested-by: Dongdong Fan <[email protected]> > --- > mm/memory_hotplug.c | 3 +-- > 1 files changed, 1 insertions(+), 2 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 26fbba7..ff658f2 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1199,8 +1199,7 @@ static int should_add_memory_movable(int nid, u64 > start, u64 size) > struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE; > > if (zone_is_empty(movable_zone)) > - return 0; > - > + return IS_ENABLED(CONFIG_MOVABLE_NODE); > if (movable_zone->zone_start_pfn <= start_pfn) > return 1; Currently, kernel allows to create ZONE_MOVABLE after ZONE_NORMAL as follows: PFN low high ---|-------------|-------------|--- ZONE_NORMAL ZONE_MOVABLE But kernel does not allow to create ZONE_MOVABLE before ZONE_NORMAL as follows: PFN low high ---|-------------|-------------|--- ZONE_MOVABLE ZONE_NORMAL Also, kernel does not allow to create ZONE_MOVABLE in ZOME_NORMAL as follows: PFN low high ---|-------------|-------------|-------------|--- ZONE_NORMAL ZONE_MOVABLE ZONE_NORMAL So should_add_memory_movable() checks them. Accoring to your patch, when movable_zone is empty, the hot added memory is always managed to ZONE_MOVABLE. It means that ZONE_MOVALBE will puts before/in ZONE_NORMAL. You must prevent from creating ZONE_MOVABLE before/in ZONE_NORMAL. Thanks, Yasuaki Ishimatsu > > -- > 1.7.1 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to [email protected]. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"[email protected]";> [email protected] </a> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
