4.6-stable review patch. If anyone has any objections, please let me know.
------------------ From: Chen Feng <puck.c...@hisilicon.com> commit 6cd9dc3e75078ef646076fa63adfb9b85ced0b66 upstream. While testing the kcompactd in my platform 3G MEM only DMA ZONE. I found the kcompactd never wakeup. It seems the zoneindex has already minus 1 before. So the traverse here should be <=. It fixes a regression where kswapd could previously compact, but kcompactd not. Not a crash fix though. [a...@linux-foundation.org: fix kcompactd_do_work() as well, per Hugh] Link: http://lkml.kernel.org/r/1463659121-84124-1-git-send-email-puck.c...@hisilicon.com Fixes: accf62422b3a ("mm, kswapd: replace kswapd compaction with waking up kcompactd") Signed-off-by: Chen Feng <puck.c...@hisilicon.com> Acked-by: Vlastimil Babka <vba...@suse.cz> Cc: Hugh Dickins <hu...@google.com> Cc: Michal Hocko <mho...@suse.com> Cc: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Cc: Johannes Weiner <han...@cmpxchg.org> Cc: Tejun Heo <t...@kernel.org> Cc: Zhuangluan Su <suzhuangl...@hisilicon.com> Cc: Yiping Xu <xuyip...@hisilicon.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- mm/compaction.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1742,7 +1742,7 @@ static bool kcompactd_node_suitable(pg_d struct zone *zone; enum zone_type classzone_idx = pgdat->kcompactd_classzone_idx; - for (zoneid = 0; zoneid < classzone_idx; zoneid++) { + for (zoneid = 0; zoneid <= classzone_idx; zoneid++) { zone = &pgdat->node_zones[zoneid]; if (!populated_zone(zone)) @@ -1777,7 +1777,7 @@ static void kcompactd_do_work(pg_data_t cc.classzone_idx); count_vm_event(KCOMPACTD_WAKE); - for (zoneid = 0; zoneid < cc.classzone_idx; zoneid++) { + for (zoneid = 0; zoneid <= cc.classzone_idx; zoneid++) { int status; zone = &pgdat->node_zones[zoneid];
