124 lines
5.0 KiB
Diff
124 lines
5.0 KiB
Diff
From f51da28ba69261a43aee45020828096b355819f8 Mon Sep 17 00:00:00 2001
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Message-Id: <f51da28ba69261a43aee45020828096b355819f8.1601675152.git.zanussi@kernel.org>
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In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Tue, 13 Mar 2018 13:49:16 +0100
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Subject: [PATCH 185/333] block: blk-mq: move blk_queue_usage_counter_release()
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into process context
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
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| BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:914
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| in_atomic(): 1, irqs_disabled(): 0, pid: 255, name: kworker/u257:6
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| 5 locks held by kworker/u257:6/255:
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| #0: ("events_unbound"){.+.+.+}, at: [<ffffffff8108edf1>] process_one_work+0x171/0x5e0
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| #1: ((&entry->work)){+.+.+.}, at: [<ffffffff8108edf1>] process_one_work+0x171/0x5e0
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| #2: (&shost->scan_mutex){+.+.+.}, at: [<ffffffffa000faa3>] __scsi_add_device+0xa3/0x130 [scsi_mod]
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| #3: (&set->tag_list_lock){+.+...}, at: [<ffffffff812f09fa>] blk_mq_init_queue+0x96a/0xa50
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| #4: (rcu_read_lock_sched){......}, at: [<ffffffff8132887d>] percpu_ref_kill_and_confirm+0x1d/0x120
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| Preemption disabled at:[<ffffffff812eff76>] blk_mq_freeze_queue_start+0x56/0x70
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| CPU: 2 PID: 255 Comm: kworker/u257:6 Not tainted 3.18.7-rt0+ #1
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| Workqueue: events_unbound async_run_entry_fn
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| 0000000000000003 ffff8800bc29f998 ffffffff815b3a12 0000000000000000
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| 0000000000000000 ffff8800bc29f9b8 ffffffff8109aa16 ffff8800bc29fa28
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| ffff8800bc5d1bc8 ffff8800bc29f9e8 ffffffff815b8dd4 ffff880000000000
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| Call Trace:
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| [<ffffffff815b3a12>] dump_stack+0x4f/0x7c
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| [<ffffffff8109aa16>] __might_sleep+0x116/0x190
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| [<ffffffff815b8dd4>] rt_spin_lock+0x24/0x60
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| [<ffffffff810b6089>] __wake_up+0x29/0x60
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| [<ffffffff812ee06e>] blk_mq_usage_counter_release+0x1e/0x20
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| [<ffffffff81328966>] percpu_ref_kill_and_confirm+0x106/0x120
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| [<ffffffff812eff76>] blk_mq_freeze_queue_start+0x56/0x70
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| [<ffffffff812f0000>] blk_mq_update_tag_set_depth+0x40/0xd0
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| [<ffffffff812f0a1c>] blk_mq_init_queue+0x98c/0xa50
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| [<ffffffffa000dcf0>] scsi_mq_alloc_queue+0x20/0x60 [scsi_mod]
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| [<ffffffffa000ea35>] scsi_alloc_sdev+0x2f5/0x370 [scsi_mod]
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| [<ffffffffa000f494>] scsi_probe_and_add_lun+0x9e4/0xdd0 [scsi_mod]
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| [<ffffffffa000fb26>] __scsi_add_device+0x126/0x130 [scsi_mod]
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| [<ffffffffa013033f>] ata_scsi_scan_host+0xaf/0x200 [libata]
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| [<ffffffffa012b5b6>] async_port_probe+0x46/0x60 [libata]
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| [<ffffffff810978fb>] async_run_entry_fn+0x3b/0xf0
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| [<ffffffff8108ee81>] process_one_work+0x201/0x5e0
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percpu_ref_kill_and_confirm() invokes blk_mq_usage_counter_release() in
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a rcu-sched region. swait based wake queue can't be used due to
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wake_up_all() usage and disabled interrupts in !RT configs (as reported
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by Corey Minyard).
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The wq_has_sleeper() check has been suggested by Peter Zijlstra.
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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block/blk-core.c | 14 +++++++++++++-
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include/linux/blkdev.h | 2 ++
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2 files changed, 15 insertions(+), 1 deletion(-)
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diff --git a/block/blk-core.c b/block/blk-core.c
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index 8926b5d998fa..964da7e39870 100644
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--- a/block/blk-core.c
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+++ b/block/blk-core.c
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@@ -973,12 +973,21 @@ void blk_queue_exit(struct request_queue *q)
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percpu_ref_put(&q->q_usage_counter);
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}
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+static void blk_queue_usage_counter_release_swork(struct swork_event *sev)
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+{
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+ struct request_queue *q =
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+ container_of(sev, struct request_queue, mq_pcpu_wake);
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+
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+ wake_up_all(&q->mq_freeze_wq);
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+}
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+
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static void blk_queue_usage_counter_release(struct percpu_ref *ref)
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{
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struct request_queue *q =
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container_of(ref, struct request_queue, q_usage_counter);
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- wake_up_all(&q->mq_freeze_wq);
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+ if (wq_has_sleeper(&q->mq_freeze_wq))
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+ swork_queue(&q->mq_pcpu_wake);
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}
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static void blk_rq_timed_out_timer(struct timer_list *t)
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@@ -1077,6 +1086,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
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queue_flag_set_unlocked(QUEUE_FLAG_BYPASS, q);
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init_waitqueue_head(&q->mq_freeze_wq);
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+ INIT_SWORK(&q->mq_pcpu_wake, blk_queue_usage_counter_release_swork);
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/*
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* Init percpu_ref in atomic mode so that it's faster to shutdown.
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@@ -3966,6 +3976,8 @@ int __init blk_dev_init(void)
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if (!kblockd_workqueue)
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panic("Failed to create kblockd\n");
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+ BUG_ON(swork_get());
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+
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request_cachep = kmem_cache_create("blkdev_requests",
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sizeof(struct request), 0, SLAB_PANIC, NULL);
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diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
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index 7cd627f2a016..cc446661e51e 100644
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--- a/include/linux/blkdev.h
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+++ b/include/linux/blkdev.h
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@@ -27,6 +27,7 @@
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#include <linux/percpu-refcount.h>
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#include <linux/scatterlist.h>
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#include <linux/blkzoned.h>
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+#include <linux/swork.h>
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struct module;
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struct scsi_ioctl_command;
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@@ -655,6 +656,7 @@ struct request_queue {
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#endif
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struct rcu_head rcu_head;
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wait_queue_head_t mq_freeze_wq;
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+ struct swork_event mq_pcpu_wake;
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struct percpu_ref q_usage_counter;
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struct list_head all_q_node;
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--
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2.17.1
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