rt-patches/0159-block-mq-do-not-invoke-preempt_disable.patch

   1 From 53beb5a2617e7a5c3674ba9324168b85f297dd08 Mon Sep 17 00:00:00 2001
   2 From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
   3 Date: Tue, 14 Jul 2015 14:26:34 +0200
   4 Subject: [PATCH 159/366] block/mq: do not invoke preempt_disable()
   5
   6 preempt_disable() and get_cpu() don't play well together with the sleeping
   7 locks it tries to allocate later.
   8 It seems to be enough to replace it with get_cpu_light() and migrate_disable().
   9
  10 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  11 ---
  12  block/blk-mq.c | 10 +++++-----
  13  1 file changed, 5 insertions(+), 5 deletions(-)
  14
  15 diff --git a/block/blk-mq.c b/block/blk-mq.c
  16 index 2d9a255..3e8e02a 100644
  17 --- a/block/blk-mq.c
  18 +++ b/block/blk-mq.c
  19 @@ -343,7 +343,7 @@ static void blk_mq_ipi_complete_request(struct request *rq)
  20                 return;
  21         }
  22
  23 -       cpu = get_cpu();
  24 +       cpu = get_cpu_light();
  25         if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
  26                 shared = cpus_share_cache(cpu, ctx->cpu);
  27
  28 @@ -355,7 +355,7 @@ static void blk_mq_ipi_complete_request(struct request *rq)
  29         } else {
  30                 rq->q->softirq_done_fn(rq);
  31         }
  32 -       put_cpu();
  33 +       put_cpu_light();
  34  }
  35
  36  static void __blk_mq_complete_request(struct request *rq)
  37 @@ -864,14 +864,14 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
  38                 return;
  39
  40         if (!async) {
  41 -               int cpu = get_cpu();
  42 +               int cpu = get_cpu_light();
  43                 if (cpumask_test_cpu(cpu, hctx->cpumask)) {
  44                         __blk_mq_run_hw_queue(hctx);
  45 -                       put_cpu();
  46 +                       put_cpu_light();
  47                         return;
  48                 }
  49
  50 -               put_cpu();
  51 +               put_cpu_light();
  52         }
  53
  54         kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
  55 --
  56 1.9.1
  57