Re: RCU warning during UBI file system mount

From: Artem Bityutskiy <dedekind1@gmail.com>
To: Subodh Nijsure <snijsure@grid-net.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-mtd@lists.infradead.org,
	Linux Kernel Maling List <linux-kernel@vger.kernel.org>
Subject: Re: RCU warning during UBI file system mount
Date: Tue, 04 Sep 2012 10:46:36 +0300	[thread overview]
Message-ID: <1346744796.12610.6.camel@sauron.fi.intel.com> (raw)
In-Reply-To: <5042EC5D.1010207@grid-net.com>

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Let's CC LKML and Paul.

On Sat, 2012-09-01 at 22:19 -0700, Subodh Nijsure wrote:
> Hello,
> 
> I am running 3.6-rc4 kernel on my MX28 based board and every time I 
> mount UBI file system I see following warning.
> Anybody else seen this errors, particularly those running it on MXS 
> platform?
> 
> I haven't debugged RCU warnings before any clues as to what is the 
> source of this warning is, should I be looking at 
> start_dma_without_bch_irq() code? Would appreciate any pointers in 
> fixing this...
> 
> [    4.280000] WARNING: at /opt/git/kernel-mainline/kernel/rcutiny.c:75 
> rcu_idle_enter_common.clone.7+0x90/0xac()
> [    4.280000] Current pid: 1 comm: swapper / Idle pid: 0 comm: swapper
> [    4.280000] Modules linked in:
> [    4.280000] [<c0014eec>] (unwind_backtrace+0x0/0x130) from 
> [<c001dd94>] (warn_slowpath_common+0x4c/0x64)
> [    4.280000] [<c001dd94>] (warn_slowpath_common+0x4c/0x64) from 
> [<c001de40>] (warn_slowpath_fmt+0x30/0x40)
> [    4.280000] [<c001de40>] (warn_slowpath_fmt+0x30/0x40) from 
> [<c0061618>] (rcu_idle_enter_common.clone.7+0x90/0xac)
> [    4.280000] [<c0061618>] (rcu_idle_enter_common.clone.7+0x90/0xac) 
> from [<c0061670>] (rcu_irq_exit+0x3c/0x78)
> [    4.280000] [<c0061670>] (rcu_irq_exit+0x3c/0x78) from [<c000fe90>] 
> (handle_IRQ+0x34/0x84)
> [    4.280000] [<c000fe90>] (handle_IRQ+0x34/0x84) from [<c000ec34>] 
> (__irq_svc+0x34/0x58)
> [    4.280000] [<c000ec34>] (__irq_svc+0x34/0x58) from [<c0394c4c>] 
> (schedule_timeout+0xdc/0x16c)
> [    4.280000] [<c0394c4c>] (schedule_timeout+0xdc/0x16c) from 
> [<c0395f34>] (wait_for_common+0xb4/0x160)
> [    4.280000] [<c0395f34>] (wait_for_common+0xb4/0x160) from 
> [<c02579d0>] (start_dma_without_bch_irq+0x6c/0xa8)
> [    4.280000] [<c02579d0>] (start_dma_without_bch_irq+0x6c/0xa8) from 
> [<c0258660>] (gpmi_send_command+0x120/0x154)
> [    4.280000] [<c0258660>] (gpmi_send_command+0x120/0x154) from 
> [<c0256fb4>] (gpmi_cmd_ctrl+0x44/0x6c)
> [    4.280000] [<c0256fb4>] (gpmi_cmd_ctrl+0x44/0x6c) from [<c024f8e0>] 
> (nand_command_lp+0xe8/0x270)
> [    4.280000] [<c024f8e0>] (nand_command_lp+0xe8/0x270) from 
> [<c0251e00>] (nand_do_read_ops+0x124/0x444)
> [    4.280000] [<c0251e00>] (nand_do_read_ops+0x124/0x444) from 
> [<c0252558>] (nand_read+0x54/0x78)
> [    4.280000] [<c0252558>] (nand_read+0x54/0x78) from [<c02499a4>] 
> (part_read+0x48/0x80)
> [    4.280000] [<c02499a4>] (part_read+0x48/0x80) from [<c0246910>] 
> (mtd_read+0x88/0xb4)
> [    4.280000] [<c0246910>] (mtd_read+0x88/0xb4) from [<c026b188>] 
> (ubi_io_read+0xb0/0x3e8)
> [    4.280000] [<c026b188>] (ubi_io_read+0xb0/0x3e8) from [<c026740c>] 
> (ubi_eba_read_leb+0x198/0x4bc)
> [    4.280000] [<c026740c>] (ubi_eba_read_leb+0x198/0x4bc) from 
> [<c0266800>] (ubi_leb_read+0xf4/0x16c)
> [    4.280000] [<c0266800>] (ubi_leb_read+0xf4/0x16c) from [<c0155550>] 
> (ubifs_leb_read+0x24/0x88)
> [    4.280000] [<c0155550>] (ubifs_leb_read+0x24/0x88) from [<c01572f8>] 
> (ubifs_read_node+0xa8/0x2e4)
> [    4.280000] [<c01572f8>] (ubifs_read_node+0xa8/0x2e4) from 
> [<c0153c50>] (ubifs_read_sb_node+0x54/0x78)
> [    4.280000] [<c0153c50>] (ubifs_read_sb_node+0x54/0x78) from 
> [<c0154940>] (ubifs_read_superblock+0xc8c/0x133c)
> [    4.280000] [<c0154940>] (ubifs_read_superblock+0xc8c/0x133c) from 
> [<c01520ac>] (ubifs_mount+0x73c/0x1bc0)
> [    4.280000] [<c01520ac>] (ubifs_mount+0x73c/0x1bc0) from [<c00a49ec>] 
> (mount_fs+0x44/0x184)
> [    4.280000] [<c00a49ec>] (mount_fs+0x44/0x184) from [<c00baf90>] 
> (vfs_kern_mount+0x4c/0xc0)
> [    4.280000] [<c00baf90>] (vfs_kern_mount+0x4c/0xc0) from [<c00bb1a0>] 
> (do_kern_mount+0x34/0xd0)
> [    4.280000] [<c00bb1a0>] (do_kern_mount+0x34/0xd0) from [<c00bc93c>] 
> (do_mount+0x15c/0x73c)
> [    4.280000] [<c00bc93c>] (do_mount+0x15c/0x73c) from [<c00bcfa0>] 
> (sys_mount+0x84/0xc4)
> [    4.280000] [<c00bcfa0>] (sys_mount+0x84/0xc4) from [<c04e4a04>] 
> (do_mount_root+0x24/0xb0)
> [    4.280000] [<c04e4a04>] (do_mount_root+0x24/0xb0) from [<c04e4b78>] 
> (mount_block_root+0xe8/0x214)
> [    4.280000] [<c04e4b78>] (mount_block_root+0xe8/0x214) from 
> [<c04e4e28>] (prepare_namespace+0x8c/0x180)
> [    4.280000] [<c04e4e28>] (prepare_namespace+0x8c/0x180) from 
> [<c04e4894>] (kernel_init+0x16c/0x1b4)
> [    4.280000] [<c04e4894>] (kernel_init+0x16c/0x1b4) from [<c000ff70>] 
> (kernel_thread_exit+0x0/0x8)
> [    4.280000] ---[ end trace 4d36b722759fdc4f ]---
> [    4.950000] UBIFS DBG (pid 58): ubifs_bg_thread: background thread 
> "ubifs_bgt0_0" started, PID 58
> 
> -Subodh
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/

-- 
Best Regards,
Artem Bityutskiy

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