From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: [PATCH V2] btrfs: implement delayed inode items operation Date: Fri, 18 Feb 2011 07:19:42 -0500 Message-ID: <1298031538-sup-7751@think> References: <4D5CB6B8.2060804@cn.fujitsu.com> <1297991261-sup-6831@think> <4D5E36FC.2050401@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Cc: Linux Btrfs , Itaru Kitayama , Ito To: miaox Return-path: In-reply-to: <4D5E36FC.2050401@cn.fujitsu.com> List-ID: 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: [] ? spin_bug+0x9c/0xa3 [] ? do_raw_spin_lock+0x63/0x13c [] ? _raw_spin_lock+0xe/0x10 [] ? btrfs_try_spin_lock+0x2a/0x86 [btrfs] [] ? btrfs_search_slot+0x5dd/0x73d [btrfs] [] ? btrfs_lookup_inode+0x2f/0x91 [btrfs] [] ? mutex_lock+0x31/0x48 [] ? btrfs_update_delayed_inode+0x73/0x11e [btrfs] [] ? start_transaction+0x19f/0x1e3 [btrfs] [] ? btrfs_async_run_delayed_node_done+0xd6/0x180 [btrfs] [] ? process_timeout+0x0/0x10 [] ? worker_loop+0x17e/0x49f [btrfs] [] ? worker_loop+0x0/0x49f [btrfs] [] ? worker_loop+0x0/0x49f [btrfs] [] ? kthread+0x82/0x8a [] ? kernel_thread_helper+0x4/0x10 [] ? kthread+0x0/0x8a [] ? kernel_thread_helper+0x0/0x10 I hit this one overnight with spinlock debugging on. Is it the same problem you've fixed? -chris