On Thu, Sep 09 2010 at 2:35pm -0400, Ryan Harper <ryanh@xxxxxxxxxx> wrote: > * Mike Snitzer <snitzer@xxxxxxxxxx> [2010-09-09 12:56]: > > I have verified that I no longer get the hang if I switch the root > > device from virtio to ide. > > And in the failing case, do you see: > > /sys/block/vda/serial > > attribute in sysfs? [root@rhel6 ~]# ls -al /sys/block/vda/serial -r--r--r-- 1 root root 4096 Sep 9 15:07 /sys/block/vda/serial [root@rhel6 ~]# cat /sys/block/vda/serial [root@rhel6 ~]# If I try to access 'serial' once the reproducer script has hung the cat also hangs: cat D 00000000fffe5d48 5664 2386 2049 0x00000080 ffff880075129ce8 0000000000000046 ffff880075129c88 ffff880000000000 ffff880075129fd8 ffff8800758aa400 00000000001d4040 ffff880075129fd8 00000000001d4040 00000000001d4040 00000000001d4040 00000000001d4040 Call Trace: [<ffffffff8136de23>] io_schedule+0x73/0xb5 [<ffffffff811b6882>] get_request_wait+0xf2/0x180 [<ffffffff8105d8da>] ? autoremove_wake_function+0x0/0x39 [<ffffffff811b6951>] blk_get_request+0x41/0x71 [<ffffffff811b69ad>] blk_make_request+0x2c/0x8b [<ffffffffa0016073>] virtblk_get_id+0x57/0x93 [virtio_blk] [<ffffffffa00160d0>] virtblk_serial_show+0x21/0x4d [virtio_blk] [<ffffffff81265f7c>] dev_attr_show+0x27/0x4e [<ffffffff81157f0b>] ? sysfs_read_file+0x94/0x17f [<ffffffff810c6d6b>] ? __get_free_pages+0x18/0x55 [<ffffffff81157f34>] sysfs_read_file+0xbd/0x17f [<ffffffff81100e7a>] vfs_read+0xab/0x108 [<ffffffff8106e428>] ? trace_hardirqs_on_caller+0x11d/0x141 [<ffffffff81100f97>] sys_read+0x4a/0x6e [<ffffffff81002bf2>] system_call_fastpath+0x16/0x1b Taking a step back; why did you make the inability to add the 'serial' attribute such a hard failure? Strikes me as worthy of a non-fatal warning at most. The serial attribute is added fine in this instance but I'm just curious. Mike -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
