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From: Marcelo Tosatti <mtosatti@redhat.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC] floppy: use single threaded workqueue
Date: Wed, 21 Jul 2010 16:55:47 -0300	[thread overview]
Message-ID: <20100721195547.GA3448@amt.cnet> (raw)
In-Reply-To: <20100611103223.799d3ce0@nehalam>

On Fri, Jun 11, 2010 at 10:32:23AM -0700, Stephen Hemminger wrote:
> Fix races between timers and bottom half by using delayed work
> and a single threaded queue.
> 
> Still needs more testing.
> 
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> 
> ---
>  drivers/block/floppy.c |  172 ++++++++++++++++++++++++++-----------------------
>  1 file changed, 94 insertions(+), 78 deletions(-)

Stephen,

Can confirm this fixes the following oops seen under KVM guests.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000035
IP: [<ffffffff812141f0>] setup_rw_floppy+0x229/0x2ca
PGD 284b8067 PUD 3d79f067 PMD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:03.0/resource
CPU 1
Modules linked in: xt_tcpudp iptable_filter ip_tables x_tables
scsi_wait_scan uhci_hcd ohci_hcd ehci_hcd

Pid: 28, comm: events/1 Not tainted 2.6.35-rc5-35033-g14e84ff #221
/Bochs RIP: 0010:[<ffffffff812141f0>]  [<ffffffff812141f0>] setup_rw_floppy+0x229/0x2ca
RSP: 0018:ffff88003e1a1e60  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000009 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000286 RDI: 0000000000000000
RBP: 00000000000000da R08: 0000000000000000 R09: ffffffff81214bdb
R10: 0000000000000000 R11: ffffffff817f7660 R12: 0000000000000000
R13: 0000000000000008 R14: ffffffff81214bdb R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff880001a40000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000035 CR3: 000000003a428000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process events/1 (pid: 28, threadinfo ffff88003e1a0000, task
ffff88003e19a8f0)
Stack:
 0000000000000000 ffff88003e1a1ef8 ffffffff81692f00 ffff880001a56680
<0> ffff88003e19a8f0 ffffffff810466f1 0000000000000000 ffff88003e19a8f0
<0> ffffffff810495ad ffff88003e1a1ea8 ffff88003e1a1ea8 ffff88003e1a1ef8
Call Trace:
 [<ffffffff810466f1>] ? worker_thread+0x150/0x1f0
 [<ffffffff810495ad>] ? autoremove_wake_function+0x0/0x2e
 [<ffffffff810465a1>] ? worker_thread+0x0/0x1f0
 [<ffffffff810492bf>] ? kthread+0x79/0x81
 [<ffffffff81002be4>] ? kernel_thread_helper+0x4/0x10



  parent reply	other threads:[~2010-07-21 20:03 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-09 18:34 [PATCH 0/8] floppy: cleanup patches Stephen Hemminger
2010-06-09 18:34 ` [PATCH 1/8] floppy: initialize debug jiffies offset Stephen Hemminger
2010-06-09 18:34 ` [PATCH 2/8] floppy: remove unnecessary inlines Stephen Hemminger
2010-06-09 18:34 ` [PATCH 3/8] floppy: silence warning during disk test Stephen Hemminger
2010-06-09 18:34 ` [PATCH 4/8] floppy: use atomic type for usage_count Stephen Hemminger
2010-06-09 18:34 ` [PATCH 5/8] floppy: cmos attribute should be static Stephen Hemminger
2010-06-09 18:34 ` [PATCH 6/8] floppy: fix signed/unsigned warnings Stephen Hemminger
2010-06-09 18:34 ` [PATCH 7/8] floppy: use wait_event_interruptible Stephen Hemminger
2010-06-09 18:34 ` [PATCH 8/8] floppy: use warning macros Stephen Hemminger
2010-06-09 18:46 ` [PATCH 0/8] floppy: cleanup patches Linus Torvalds
2010-06-09 18:54   ` Stephen Hemminger
2010-06-09 19:04     ` Linus Torvalds
2010-06-11 17:32       ` [RFC] floppy: use single threaded workqueue Stephen Hemminger
2010-06-11 18:56         ` Linus Torvalds
2010-07-21 19:55         ` Marcelo Tosatti [this message]
2010-07-22 19:09           ` Linus Torvalds
2010-07-22 22:22             ` david
2010-07-22 23:00               ` Linus Torvalds
2010-08-22  9:07               ` Amos Kong
2010-08-23 22:22                 ` Stephen Hemminger
2010-06-10  6:43 ` [PATCH 0/8] floppy: cleanup patches Thomas Meyer
2010-06-11 17:30   ` Stephen Hemminger
2010-06-13 17:23     ` Thomas Meyer

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