[PATCH] cfq-iosched: Fixed boot warning with BLK_CGROUP=y andCFQ_GROUP_IOSCHED=n

From: Vivek Goyal
Date: Fri Jun 18 2010 - 10:40:15 EST


Hi Jens,

Few days back Ingo noticed a CFQ boot time warning. This patch fixes it.
The issue here is that with CFQ_GROUP_IOSCHED=n, CFQ should not really
be making blkio stat related calls.

> Hm, it's still not entirely fixed, as of 2.6.35-rc2-00131-g7908a9e. With
> some
> configs i get bad spinlock warnings during bootup:
>
> [ 28.968013] initcall net_olddevs_init+0x0/0x82 returned 0 after 93750
> usecs
> [ 28.972003] calling b44_init+0x0/0x55 @ 1
> [ 28.976009] bus: 'pci': add driver b44
> [ 28.976374] sda:
> [ 28.978157] BUG: spinlock bad magic on CPU#1, async/0/117
> [ 28.980000] lock: 7e1c5bbc, .magic: 00000000, .owner: <none>/-1, +.owner_cpu: 0
> [ 28.980000] Pid: 117, comm: async/0 Not tainted +2.6.35-rc2-tip-01092-g010e7ef-dirty #8183
> [ 28.980000] Call Trace:
> [ 28.980000] [<41ba6d55>] ? printk+0x20/0x24
> [ 28.980000] [<4134b7b7>] spin_bug+0x7c/0x87
> [ 28.980000] [<4134b853>] do_raw_spin_lock+0x1e/0x123
> [ 28.980000] [<41ba92ca>] ? _raw_spin_lock_irqsave+0x12/0x20
> [ 28.980000] [<41ba92d2>] _raw_spin_lock_irqsave+0x1a/0x20
> [ 28.980000] [<4133476f>] blkiocg_update_io_add_stats+0x25/0xfb
> [ 28.980000] [<41335dae>] ? cfq_prio_tree_add+0xb1/0xc1
> [ 28.980000] [<41337bc7>] cfq_insert_request+0x8c/0x425


Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
block/cfq-iosched.c | 54 ++++++++++++------------
block/cfq.h | 115 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 142 insertions(+), 27 deletions(-)

Index: linux-2.6/block/cfq-iosched.c
===================================================================
--- linux-2.6.orig/block/cfq-iosched.c 2010-06-18 09:40:46.403163874 -0400
+++ linux-2.6/block/cfq-iosched.c 2010-06-18 09:47:58.747339881 -0400
@@ -14,7 +14,7 @@
#include <linux/rbtree.h>
#include <linux/ioprio.h>
#include <linux/blktrace_api.h>
-#include "blk-cgroup.h"
+#include "cfq.h"

/*
* tunables
@@ -879,7 +879,7 @@
if (!RB_EMPTY_NODE(&cfqg->rb_node))
cfq_rb_erase(&cfqg->rb_node, st);
cfqg->saved_workload_slice = 0;
- blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
+ cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
}

static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq)
@@ -939,8 +939,8 @@

cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
st->min_vdisktime);
- blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
- blkiocg_set_start_empty_time(&cfqg->blkg);
+ cfq_blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
+ cfq_blkiocg_set_start_empty_time(&cfqg->blkg);
}

#ifdef CONFIG_CFQ_GROUP_IOSCHED
@@ -995,7 +995,7 @@

/* Add group onto cgroup list */
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
- blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
+ cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
MKDEV(major, minor));
cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);

@@ -1079,7 +1079,7 @@
* it from cgroup list, then it will take care of destroying
* cfqg also.
*/
- if (!blkiocg_del_blkio_group(&cfqg->blkg))
+ if (!cfq_blkiocg_del_blkio_group(&cfqg->blkg))
cfq_destroy_cfqg(cfqd, cfqg);
}
}
@@ -1421,10 +1421,10 @@
{
elv_rb_del(&cfqq->sort_list, rq);
cfqq->queued[rq_is_sync(rq)]--;
- blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(rq),
- rq_is_sync(rq));
+ cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,
+ rq_data_dir(rq), rq_is_sync(rq));
cfq_add_rq_rb(rq);
- blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
+ cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
&cfqq->cfqd->serving_group->blkg, rq_data_dir(rq),
rq_is_sync(rq));
}
@@ -1482,8 +1482,8 @@
cfq_del_rq_rb(rq);

cfqq->cfqd->rq_queued--;
- blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(rq),
- rq_is_sync(rq));
+ cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,
+ rq_data_dir(rq), rq_is_sync(rq));
if (rq_is_meta(rq)) {
WARN_ON(!cfqq->meta_pending);
cfqq->meta_pending--;
@@ -1518,8 +1518,8 @@
static void cfq_bio_merged(struct request_queue *q, struct request *req,
struct bio *bio)
{
- blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg, bio_data_dir(bio),
- cfq_bio_sync(bio));
+ cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg,
+ bio_data_dir(bio), cfq_bio_sync(bio));
}

static void
@@ -1539,8 +1539,8 @@
if (cfqq->next_rq == next)
cfqq->next_rq = rq;
cfq_remove_request(next);
- blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(next),
- rq_is_sync(next));
+ cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg,
+ rq_data_dir(next), rq_is_sync(next));
}

static int cfq_allow_merge(struct request_queue *q, struct request *rq,
@@ -1571,7 +1571,7 @@
static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
del_timer(&cfqd->idle_slice_timer);
- blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
+ cfq_blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
}

static void __cfq_set_active_queue(struct cfq_data *cfqd,
@@ -1580,7 +1580,7 @@
if (cfqq) {
cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
cfqd->serving_prio, cfqd->serving_type);
- blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
+ cfq_blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
cfqq->slice_start = 0;
cfqq->dispatch_start = jiffies;
cfqq->allocated_slice = 0;
@@ -1911,7 +1911,7 @@
sl = cfqd->cfq_slice_idle;

mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
- blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg);
+ cfq_blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg);
cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl);
}

@@ -1931,7 +1931,7 @@
elv_dispatch_sort(q, rq);

cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
- blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq),
+ cfq_blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq),
rq_data_dir(rq), rq_is_sync(rq));
}

@@ -3248,7 +3248,7 @@
cfq_clear_cfqq_wait_request(cfqq);
__blk_run_queue(cfqd->queue);
} else {
- blkiocg_update_idle_time_stats(
+ cfq_blkiocg_update_idle_time_stats(
&cfqq->cfqg->blkg);
cfq_mark_cfqq_must_dispatch(cfqq);
}
@@ -3276,7 +3276,7 @@
rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]);
list_add_tail(&rq->queuelist, &cfqq->fifo);
cfq_add_rq_rb(rq);
- blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
+ cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
&cfqd->serving_group->blkg, rq_data_dir(rq),
rq_is_sync(rq));
cfq_rq_enqueued(cfqd, cfqq, rq);
@@ -3364,9 +3364,9 @@
WARN_ON(!cfqq->dispatched);
cfqd->rq_in_driver--;
cfqq->dispatched--;
- blkiocg_update_completion_stats(&cfqq->cfqg->blkg, rq_start_time_ns(rq),
- rq_io_start_time_ns(rq), rq_data_dir(rq),
- rq_is_sync(rq));
+ cfq_blkiocg_update_completion_stats(&cfqq->cfqg->blkg,
+ rq_start_time_ns(rq), rq_io_start_time_ns(rq),
+ rq_data_dir(rq), rq_is_sync(rq));

cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;

@@ -3730,7 +3730,7 @@

cfq_put_async_queues(cfqd);
cfq_release_cfq_groups(cfqd);
- blkiocg_del_blkio_group(&cfqd->root_group.blkg);
+ cfq_blkiocg_del_blkio_group(&cfqd->root_group.blkg);

spin_unlock_irq(q->queue_lock);

@@ -3798,8 +3798,8 @@
*/
atomic_set(&cfqg->ref, 1);
rcu_read_lock();
- blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd,
- 0);
+ cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg,
+ (void *)cfqd, 0);
rcu_read_unlock();
#endif
/*
Index: linux-2.6/block/cfq.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/block/cfq.h 2010-06-18 09:41:23.256220395 -0400
@@ -0,0 +1,115 @@
+#ifndef _CFQ_H
+#define _CFQ_H
+#include "blk-cgroup.h"
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+static inline void cfq_blkiocg_update_io_add_stats(struct blkio_group *blkg,
+ struct blkio_group *curr_blkg, bool direction, bool sync)
+{
+ blkiocg_update_io_add_stats(blkg, curr_blkg, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_dequeue_stats(struct blkio_group *blkg,
+ unsigned long dequeue)
+{
+ blkiocg_update_dequeue_stats(blkg, dequeue);
+}
+
+static inline void cfq_blkiocg_update_timeslice_used(struct blkio_group *blkg,
+ unsigned long time)
+{
+ blkiocg_update_timeslice_used(blkg, time);
+}
+
+static inline void cfq_blkiocg_set_start_empty_time(struct blkio_group *blkg)
+{
+ blkiocg_set_start_empty_time(blkg);
+}
+
+static inline void cfq_blkiocg_update_io_remove_stats(struct blkio_group *blkg,
+ bool direction, bool sync)
+{
+ blkiocg_update_io_remove_stats(blkg, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_io_merged_stats(struct blkio_group *blkg,
+ bool direction, bool sync)
+{
+ blkiocg_update_io_merged_stats(blkg, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_idle_time_stats(struct blkio_group *blkg)
+{
+ blkiocg_update_idle_time_stats(blkg);
+}
+
+static inline void
+cfq_blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg)
+{
+ blkiocg_update_avg_queue_size_stats(blkg);
+}
+
+static inline void
+cfq_blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
+{
+ blkiocg_update_set_idle_time_stats(blkg);
+}
+
+static inline void cfq_blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+ uint64_t bytes, bool direction, bool sync)
+{
+ blkiocg_update_dispatch_stats(blkg, bytes, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg, uint64_t start_time, uint64_t io_start_time, bool direction, bool sync)
+{
+ cfq_blkiocg_update_completion_stats(blkg, start_time, io_start_time,
+ direction, sync);
+}
+
+static inline void cfq_blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
+ struct blkio_group *blkg, void *key, dev_t dev) {
+ blkiocg_add_blkio_group(blkcg, blkg, key, dev);
+}
+
+static inline int cfq_blkiocg_del_blkio_group(struct blkio_group *blkg)
+{
+ return blkiocg_del_blkio_group(blkg);
+}
+
+#else /* CFQ_GROUP_IOSCHED */
+static inline void cfq_blkiocg_update_io_add_stats(struct blkio_group *blkg,
+ struct blkio_group *curr_blkg, bool direction, bool sync) {}
+
+static inline void cfq_blkiocg_update_dequeue_stats(struct blkio_group *blkg,
+ unsigned long dequeue) {}
+
+static inline void cfq_blkiocg_update_timeslice_used(struct blkio_group *blkg,
+ unsigned long time) {}
+static inline void cfq_blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
+static inline void cfq_blkiocg_update_io_remove_stats(struct blkio_group *blkg,
+ bool direction, bool sync) {}
+static inline void cfq_blkiocg_update_io_merged_stats(struct blkio_group *blkg,
+ bool direction, bool sync) {}
+static inline void cfq_blkiocg_update_idle_time_stats(struct blkio_group *blkg)
+{
+}
+static inline void
+cfq_blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg) {}
+
+static inline void
+cfq_blkiocg_update_set_idle_time_stats(struct blkio_group *blkg) {}
+
+static inline void cfq_blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+ uint64_t bytes, bool direction, bool sync) {}
+static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg, uint64_t start_time, uint64_t io_start_time, bool direction, bool sync) {}
+
+static inline void cfq_blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
+ struct blkio_group *blkg, void *key, dev_t dev) {}
+static inline int cfq_blkiocg_del_blkio_group(struct blkio_group *blkg)
+{
+ return 0;
+}
+
+#endif /* CFQ_GROUP_IOSCHED */
+#endif
--
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