From: Chen Feng <puck.chen@xxxxxxxxxxxxx> Subject: mm/compaction.c: fix zoneindex in kcompactd() 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. [akpm@xxxxxxxxxxxxxxxxxxxx: fix kcompactd_do_work() as well, per Hugh] Link: http://lkml.kernel.org/r/1463659121-84124-1-git-send-email-puck.chen@xxxxxxxxxxxxx Fixes: accf62422b3a ("mm, kswapd: replace kswapd compaction with waking up kcompactd") Signed-off-by: Chen Feng <puck.chen@xxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Zhuangluan Su <suzhuangluan@xxxxxxxxxxxxx> Cc: Yiping Xu <xuyiping@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/compaction.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN mm/compaction.c~mm-compact-fix-zoneindex-in-compact mm/compaction.c --- a/mm/compaction.c~mm-compact-fix-zoneindex-in-compact +++ a/mm/compaction.c @@ -1862,7 +1862,7 @@ 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)) @@ -1897,7 +1897,7 @@ 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]; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
