releases/4.4.157/block-blkcg-use-__gfp_nowarn-for-best-effort-allocations-in-blkcg.patch

   1 From e00f4f4d0ff7e13b9115428a245b49108d625f09 Mon Sep 17 00:00:00 2001
   2 From: Tejun Heo <tj@kernel.org>
   3 Date: Mon, 21 Nov 2016 18:03:32 -0500
   4 Subject: block,blkcg: use __GFP_NOWARN for best-effort allocations in blkcg
   5
   6 From: Tejun Heo <tj@kernel.org>
   7
   8 commit e00f4f4d0ff7e13b9115428a245b49108d625f09 upstream.
   9
  10 blkcg allocates some per-cgroup data structures with GFP_NOWAIT and
  11 when that fails falls back to operations which aren't specific to the
  12 cgroup.  Occassional failures are expected under pressure and falling
  13 back to non-cgroup operation is the right thing to do.
  14
  15 Unfortunately, I forgot to add __GFP_NOWARN to these allocations and
  16 these expected failures end up creating a lot of noise.  Add
  17 __GFP_NOWARN.
  18
  19 Signed-off-by: Tejun Heo <tj@kernel.org>
  20 Reported-by: Marc MERLIN <marc@merlins.org>
  21 Reported-by: Vlastimil Babka <vbabka@suse.cz>
  22 Signed-off-by: Jens Axboe <axboe@fb.com>
  23 Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25
  26 ---
  27  block/blk-cgroup.c  |    9 +++++----
  28  block/cfq-iosched.c |    3 ++-
  29  2 files changed, 7 insertions(+), 5 deletions(-)
  30
  31 --- a/block/blk-cgroup.c
  32 +++ b/block/blk-cgroup.c
  33 @@ -185,7 +185,8 @@ static struct blkcg_gq *blkg_create(stru
  34         }
  35
  36         wb_congested = wb_congested_get_create(&q->backing_dev_info,
  37 -                                              blkcg->css.id, GFP_NOWAIT);
  38 +                                              blkcg->css.id,
  39 +                                              GFP_NOWAIT | __GFP_NOWARN);
  40         if (!wb_congested) {
  41                 ret = -ENOMEM;
  42                 goto err_put_css;
  43 @@ -193,7 +194,7 @@ static struct blkcg_gq *blkg_create(stru
  44
  45         /* allocate */
  46         if (!new_blkg) {
  47 -               new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT);
  48 +               new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT | __GFP_NOWARN);
  49                 if (unlikely(!new_blkg)) {
  50                         ret = -ENOMEM;
  51                         goto err_put_congested;
  52 @@ -1022,7 +1023,7 @@ blkcg_css_alloc(struct cgroup_subsys_sta
  53         }
  54
  55         spin_lock_init(&blkcg->lock);
  56 -       INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT);
  57 +       INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT | __GFP_NOWARN);
  58         INIT_HLIST_HEAD(&blkcg->blkg_list);
  59  #ifdef CONFIG_CGROUP_WRITEBACK
  60         INIT_LIST_HEAD(&blkcg->cgwb_list);
  61 @@ -1238,7 +1239,7 @@ pd_prealloc:
  62                 if (blkg->pd[pol->plid])
  63                         continue;
  64
  65 -               pd = pol->pd_alloc_fn(GFP_NOWAIT, q->node);
  66 +               pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q->node);
  67                 if (!pd)
  68                         swap(pd, pd_prealloc);
  69                 if (!pd) {
  70 --- a/block/cfq-iosched.c
  71 +++ b/block/cfq-iosched.c
  72 @@ -3811,7 +3811,8 @@ cfq_get_queue(struct cfq_data *cfqd, boo
  73                         goto out;
  74         }
  75
  76 -       cfqq = kmem_cache_alloc_node(cfq_pool, GFP_NOWAIT | __GFP_ZERO,
  77 +       cfqq = kmem_cache_alloc_node(cfq_pool,
  78 +                                    GFP_NOWAIT | __GFP_ZERO | __GFP_NOWARN,
  79                                      cfqd->queue->node);
  80         if (!cfqq) {
  81                 cfqq = &cfqd->oom_cfqq;