block,blkcg: use __GFP_NOWARN for best-effort allocations in blkcg

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@kernel.org>
Reported-by: Marc MERLIN <marc@merlins.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 6cd839c..f570f38 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -185,7 +185,8 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
        }
 
        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(struct blkcg *blkcg,
 
        /* 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_state *parent_css)
        }
 
        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) {

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index b2dc1c1..a4e2d01 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3868,7 +3868,8 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
                        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;