AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

mm, memory_hotplug: fix MMOP_ONLINE_KEEP behavior

Browse Source 
Heiko Carstens has noticed that the MMOP_ONLINE_KEEP is broken currently

  $ grep . memory3?/valid_zones
  memory34/valid_zones:Normal Movable
  memory35/valid_zones:Normal Movable
  memory36/valid_zones:Normal Movable
  memory37/valid_zones:Normal Movable

  $ echo online_movable > memory34/state
  $ grep . memory3?/valid_zones
  memory34/valid_zones:Movable
  memory35/valid_zones:Movable
  memory36/valid_zones:Movable
  memory37/valid_zones:Movable

  $ echo online > memory36/state
  $ grep . memory3?/valid_zones
  memory34/valid_zones:Movable
  memory36/valid_zones:Normal
  memory37/valid_zones:Movable

so we have effectively punched a hole into the movable zone.

The problem is that move_pfn_range() check for MMOP_ONLINE_KEEP is
wrong.  It only checks whether the given range is already part of the
movable zone which is not the case here as only memory34 is in the zone.
Fix this by using allow_online_pfn_range(..., MMOP_ONLINE_KERNEL) if
that is false then we can be sure that movable onlining is the right
thing to do.

Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online"
Link: http://lkml.kernel.org/r/20170601083746.4924-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michal Hocko 2017-07-06 15:38:15 -07:00 committed by Linus Torvalds
parent f1dd2cd13c
commit a69578a154
1 changed files with 5 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
mm/memory_hotplug.c
View File

@ -1115,11 +1115,12 @@ static struct zone * __meminit move_pfn_range(int online_type, int nid,
if (online_type == MMOP_ONLINE_KEEP) {
struct zone *movable_zone = &pgdat->node_zones[ZONE_MOVABLE];
/*
* MMOP_ONLINE_KEEP inherits the current zone which is
* ZONE_NORMAL by default but we might be within ZONE_MOVABLE
* already.
* MMOP_ONLINE_KEEP defaults to MMOP_ONLINE_KERNEL but use
* movable zone if that is not possible (e.g. we are within
* or past the existing movable zone)
*/
if (zone_intersects(movable_zone, start_pfn, nr_pages))
if (!allow_online_pfn_range(nid, start_pfn, nr_pages,
MMOP_ONLINE_KERNEL))
zone = movable_zone;
} else if (online_type == MMOP_ONLINE_MOVABLE) {
zone = &pgdat->node_zones[ZONE_MOVABLE];