4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tejun Heo <tj@xxxxxxxxxx> commit e00f4f4d0ff7e13b9115428a245b49108d625f09 upstream. blkcg allocates some per-cgroup data structures with GFP_NOWAIT and when that fails falls back to operations which aren't specific to the cgroup. Occassional failures are expected under pressure and falling back to non-cgroup operation is the right thing to do. Unfortunately, I forgot to add __GFP_NOWARN to these allocations and these expected failures end up creating a lot of noise. Add __GFP_NOWARN. Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Reported-by: Marc MERLIN <marc@xxxxxxxxxxx> Reported-by: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxx> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- block/blk-cgroup.c | 9 +++++---- block/cfq-iosched.c | 3 ++- 2 files changed, 7 insertions(+), 5 deletions(-) --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -185,7 +185,8 @@ static struct blkcg_gq *blkg_create(stru } wb_congested = wb_congested_get_create(&q->backing_dev_info, - blkcg->css.id, GFP_NOWAIT); + blkcg->css.id, + GFP_NOWAIT | __GFP_NOWARN); if (!wb_congested) { ret = -ENOMEM; goto err_put_css; @@ -193,7 +194,7 @@ static struct blkcg_gq *blkg_create(stru /* allocate */ if (!new_blkg) { - new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT); + new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT | __GFP_NOWARN); if (unlikely(!new_blkg)) { ret = -ENOMEM; goto err_put_congested; @@ -1022,7 +1023,7 @@ blkcg_css_alloc(struct cgroup_subsys_sta } spin_lock_init(&blkcg->lock); - INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT); + INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT | __GFP_NOWARN); INIT_HLIST_HEAD(&blkcg->blkg_list); #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&blkcg->cgwb_list); @@ -1238,7 +1239,7 @@ pd_prealloc: if (blkg->pd[pol->plid]) continue; - pd = pol->pd_alloc_fn(GFP_NOWAIT, q->node); + pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q->node); if (!pd) swap(pd, pd_prealloc); if (!pd) { --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3868,7 +3868,8 @@ cfq_get_queue(struct cfq_data *cfqd, boo goto out; } - cfqq = kmem_cache_alloc_node(cfq_pool, GFP_NOWAIT | __GFP_ZERO, + cfqq = kmem_cache_alloc_node(cfq_pool, + GFP_NOWAIT | __GFP_ZERO | __GFP_NOWARN, cfqd->queue->node); if (!cfqq) { cfqq = &cfqd->oom_cfqq;