Excerpts from Miao Xie's message of 2011-02-18 08:09:28 -0500: > On fri, 18 Feb 2011 07:19:42 -0500, Chris Mason wrote: > > Excerpts from Miao Xie's message of 2011-02-18 04:08:12 -0500: > >> Hi, Chris > >> CC Tsutomu Itoh > >> > >> On Thu, 17 Feb 2011 20:09:00 -0500, Chris Mason wrote: > >>> Excerpts from Miao Xie's message of 2011-02-17 00:48:40 -0500: > >>>> Compare with Ext3/4, the performance of file creation and deletion on > >>>> btrfs > >>>> is very poor. the reason is that btrfs must do a lot of b+ tree > >>>> insertions, > >>>> such as inode item, directory name item, directory name index and so on. > >>>> > >>>> If we can do some delayed b+ tree insertion or deletion, we can improve > >>>> the > >>>> performance, so we made this patch which implemented delayed directory > >>>> name > >>>> index insertion/deletion and delayed inode update. > >>> > >>> This work is really cool, thanks for doing it. I'm starting a run on > >>> this tonight and if all goes well I'll review in detail and try to queue > >>> it along with the per-subvolume storage bits for .39. > >> > >> There is a hang-up problem in this patch, that is the task which does > >> delayed item > >> balance and the task which commits the transaction will wait for each > >> other, and > >> the filesystem will hang up. This is reported by Tsutomu Itoh. > >> > >> I have made the third version of this patch, will post it later. > > > > BUG: spinlock cpu recursion on CPU#2, btrfs-delayed-m/2762 > > lock: ffff88004f47bfb0, .magic: dead4ead, .owner: btrfs-delayed-m/2763, > > .owner_cpu: 2 > > Pid: 2762, comm: btrfs-delayed-m Not tainted 2.6.38-rc4-josef+ #209 > > Call Trace: > > [<ffffffff812621f1>] ? spin_bug+0x9c/0xa3 > > [<ffffffff8126225b>] ? do_raw_spin_lock+0x63/0x13c > > [<ffffffff815c31c5>] ? _raw_spin_lock+0xe/0x10 > > [<ffffffffa004e5e3>] ? btrfs_try_spin_lock+0x2a/0x86 [btrfs] > > [<ffffffffa000ddc1>] ? btrfs_search_slot+0x5dd/0x73d [btrfs] > > [<ffffffffa001e77e>] ? btrfs_lookup_inode+0x2f/0x91 [btrfs] > > [<ffffffff815c21b2>] ? mutex_lock+0x31/0x48 > > [<ffffffffa0061ac8>] ? btrfs_update_delayed_inode+0x73/0x11e [btrfs] > > [<ffffffffa0025454>] ? start_transaction+0x19f/0x1e3 [btrfs] > > [<ffffffffa0062026>] ? btrfs_async_run_delayed_node_done+0xd6/0x180 > > [btrfs] > > [<ffffffff8107c0e9>] ? process_timeout+0x0/0x10 > > [<ffffffffa004a44f>] ? worker_loop+0x17e/0x49f [btrfs] > > [<ffffffffa004a2d1>] ? worker_loop+0x0/0x49f [btrfs] > > [<ffffffffa004a2d1>] ? worker_loop+0x0/0x49f [btrfs] > > [<ffffffff81089d9c>] ? kthread+0x82/0x8a > > [<ffffffff810347d4>] ? kernel_thread_helper+0x4/0x10 > > [<ffffffff81089d1a>] ? kthread+0x0/0x8a > > [<ffffffff810347d0>] ? kernel_thread_helper+0x0/0x10 > > > > > > I hit this one overnight with spinlock debugging on. Is it the same > > problem you've fixed? > > I haven't hit this bug, could you tell me the reproduce steps?
I just ran dbench 50. But I have spinlock debugging turned on (CONFIG_DEBUG_SPINLOCK). Looks like the patch probably forgot to unlock or release a path, I'll take a quick look. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
