On Wed, Mar 14, 2012 at 09:32:28AM -0400, Kent Overstreet wrote: > I'm already registered to attend, but would it be too late in the > process to give a talk? I'd like to give a short talk about bcache, what > it does and where it's going (more than just caching). [CCing dm-devel list] I am curious if you considered writing a device mapper driver for this? If yes, why that is not a good choice. It seems to be stacked device and device mapper should be good at that. All the configuration through sysfs seems little odd to me. On a side note, I was playing with bcache a bit. I tried to register the cache device and it crashes. (I guess I should post this on relevant mailing list). # echo /dev/sdc > /sys/fs/bcache/register [ 6758.314093] Pid: 0, comm: kworker/0:1 Not tainted 3.1.0-bcache+ #2 Hewlett-Packard HP xw6600 Workstation/0A9Ch [ 6758.314093] RIP: 0010:[<ffffffff8146625b>] [<ffffffff8146625b>] closure_put+0x5b/0xe0 [ 6758.314093] RSP: 0018:ffff88013fc83c60 EFLAGS: 00010246 [ 6758.314093] RAX: 6b6b6b6b6b6b6b6b RBX: ffff8801281204a0 RCX: 0000000000000000 [ 6758.314093] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff88013906ec48 [ 6758.314093] RBP: ffff88013fc83c60 R08: 0000000000000000 R09: 0000000000000001 [ 6758.314093] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 6758.314093] R13: ffff880130b58560 R14: 0000000000080000 R15: 0000000000000000 [ 6758.314093] FS: 0000000000000000(0000) GS:ffff88013fc80000(0000) knlGS:0000000000000000 [ 6758.314093] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 6758.314093] CR2: 00007f9becec7000 CR3: 0000000137fe0000 CR4: 00000000000006e0 [ 6758.314093] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6758.314093] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 6758.314093] Process kworker/0:1 (pid: 0, threadinfo ffff88013a44a000, task ffff88013a458000) [ 6758.314093] Stack: [ 6758.314093] ffff88013fc83c80 ffffffff8145ee6d ffffffff00000000 ffff8801281204a0 [ 6758.314093] ffff88013fc83c90 ffffffff81173a9d ffff88013fc83cc0 ffffffff812d15d3 [ 6758.314093] ffff88013a44a000 0000000000000000 ffff8801281204a0 0000000000080000 [ 6758.314093] Call Trace: [ 6758.314093] <IRQ> [ 6758.314093] [<ffffffff8145ee6d>] uuid_endio+0x3d/0x50 [ 6758.314093] [<ffffffff81173a9d>] bio_endio+0x1d/0x40 [ 6758.314093] [<ffffffff812d15d3>] req_bio_endio+0x83/0xc0 [ 6758.314093] [<ffffffff812d4f71>] blk_update_request+0x101/0x5c0 [ 6758.314093] [<ffffffff812d51a2>] ? blk_update_request+0x332/0x5c0 [ 6758.314093] [<ffffffff812d5461>] blk_update_bidi_request+0x31/0x90 [ 6758.314093] [<ffffffff812d54ec>] blk_end_bidi_request+0x2c/0x80 [ 6758.314093] [<ffffffff812d5580>] blk_end_request+0x10/0x20 [ 6758.314093] [<ffffffff81471b7c>] scsi_io_completion+0x9c/0x5f0 [ 6758.314093] [<ffffffff81468940>] scsi_finish_command+0xb0/0xe0 [ 6758.314093] [<ffffffff81471965>] scsi_softirq_done+0xa5/0x140 [ 6758.314093] [<ffffffff812db70b>] blk_done_softirq+0x7b/0x90 [ 6758.314093] [<ffffffff8104fc65>] __do_softirq+0xc5/0x3a0 [ 6758.314093] [<ffffffff817f6dac>] call_softirq+0x1c/0x30 [ 6758.314093] [<ffffffff8100419d>] do_softirq+0x8d/0xc0 [ 6758.314093] [<ffffffff8105027e>] irq_exit+0xae/0xe0 [ 6758.314093] [<ffffffff817f74b3>] do_IRQ+0x63/0xe0 [ 6758.314093] [<ffffffff817ecc30>] common_interrupt+0x70/0x70 [ 6758.314093] <EOI> [ 6758.314093] [<ffffffff8100a1f6>] ? mwait_idle+0xb6/0x470 [ 6758.314093] [<ffffffff8100a1ed>] ? mwait_idle+0xad/0x470 [ 6758.314093] [<ffffffff810011df>] cpu_idle+0x8f/0xd0 [ 6758.314093] [<ffffffff817da107>] start_secondary+0x1be/0x1c2 [ 6758.314093] Code: 00 48 8b 50 48 83 e2 08 0f 85 9c 00 00 00 48 8b 50 48 83 e2 10 0f 85 8d 00 00 00 48 83 78 18 00 75 46 48 8b 40 40 48 85 c0 74 24 [ 6758.314093] 8b 50 48 48 c1 ea 04 89 d1 89 f2 83 e1 01 f0 0f c1 50 4c 83 [ 6758.314093] RIP [<ffffffff8146625b>] closure_put+0x5b/0xe0 [ 6758.314093] RSP <ffff88013fc83c60> Thanks Vivek -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
