On 10/26/2016 04:00 PM, Chris Mason wrote: > > > On 10/26/2016 03:06 PM, Linus Torvalds wrote: >> On Wed, Oct 26, 2016 at 11:42 AM, Dave Jones <da...@codemonkey.org.uk> wrote: >>> >>> The stacks show nearly all of them are stuck in sync_inodes_sb >> >> That's just wb_wait_for_completion(), and it means that some IO isn't >> completing. >> >> There's also a lot of processes waiting for inode_lock(), and a few >> waiting for mnt_want_write() >> >> Ignoring those, we have >> >>> [<ffffffffa009554f>] btrfs_wait_ordered_roots+0x3f/0x200 [btrfs] >>> [<ffffffffa00470d1>] btrfs_sync_fs+0x31/0xc0 [btrfs] >>> [<ffffffff811fbd4e>] sync_filesystem+0x6e/0xa0 >>> [<ffffffff811fbebc>] SyS_syncfs+0x3c/0x70 >>> [<ffffffff8100255c>] do_syscall_64+0x5c/0x170 >>> [<ffffffff817908cb>] entry_SYSCALL64_slow_path+0x25/0x25 >>> [<ffffffffffffffff>] 0xffffffffffffffff >> >> Don't know this one. There's a couple of them. Could there be some >> ABBA deadlock on the ordered roots waiting? > > It's always possible, but we haven't changed anything here. > > I've tried a long list of things to reproduce this on my test boxes, > including days of trinity runs and a kernel module to exercise vmalloc, > and thread creation. > > Today I turned off every CONFIG_DEBUG_* except for list debugging, and > ran dbench 2048: >
This one is special because CONFIG_VMAP_STACK is not set. Btrfs triggers in < 10 minutes. I've done 30 minutes each with XFS and Ext4 without luck. This is all in a virtual machine that I can copy on to a bunch of hosts. So I'll get some parallel tests going tonight to narrow it down. ------------[ cut here ]------------ WARNING: CPU: 6 PID: 4481 at lib/list_debug.c:33 __list_add+0xbe/0xd0 list_add corruption. prev->next should be next (ffffe8ffffd80b08), but was ffff88012b65fb88. (prev=ffff880128c8d500). Modules linked in: crc32c_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper i2c_piix4 cryptd i2c_core virtio_net serio_raw floppy button pcspkr sch_fq_codel autofs4 virtio_blk CPU: 6 PID: 4481 Comm: dbench Not tainted 4.9.0-rc2-15419-g811d54d #319 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.0-1.fc24 04/01/2014 ffff880104eff868 ffffffff814fde0f ffffffff8151c46e ffff880104eff8c8 ffff880104eff8c8 0000000000000000 ffff880104eff8b8 ffffffff810648cf ffff880128cab2c0 000000213fc57c68 ffff8801384e8928 ffff880128cab180 Call Trace: [<ffffffff814fde0f>] dump_stack+0x53/0x74 [<ffffffff8151c46e>] ? __list_add+0xbe/0xd0 [<ffffffff810648cf>] __warn+0xff/0x120 [<ffffffff810649a9>] warn_slowpath_fmt+0x49/0x50 [<ffffffff8151c46e>] __list_add+0xbe/0xd0 [<ffffffff814dec38>] blk_sq_make_request+0x388/0x580 [<ffffffff814d5444>] generic_make_request+0x104/0x200 [<ffffffff814d55a5>] submit_bio+0x65/0x130 [<ffffffff8152a256>] ? __percpu_counter_add+0x96/0xd0 [<ffffffff81425c7c>] btrfs_map_bio+0x23c/0x310 [<ffffffff813f3e73>] btrfs_submit_bio_hook+0xd3/0x190 [<ffffffff8141136d>] submit_one_bio+0x6d/0xa0 [<ffffffff814113ee>] flush_epd_write_bio+0x4e/0x70 [<ffffffff8141894d>] extent_writepages+0x5d/0x70 [<ffffffff813f80a0>] ? btrfs_releasepage+0x50/0x50 [<ffffffff81220d0e>] ? wbc_attach_and_unlock_inode+0x6e/0x170 [<ffffffff813f4c07>] btrfs_writepages+0x27/0x30 [<ffffffff811783a0>] do_writepages+0x20/0x30 [<ffffffff81167a95>] __filemap_fdatawrite_range+0xb5/0x100 [<ffffffff81167f73>] filemap_fdatawrite_range+0x13/0x20 [<ffffffff8140563b>] btrfs_fdatawrite_range+0x2b/0x70 [<ffffffff81405768>] btrfs_sync_file+0x88/0x490 [<ffffffff81074ef2>] ? group_send_sig_info+0x42/0x80 [<ffffffff81074f8d>] ? kill_pid_info+0x5d/0x90 [<ffffffff8107535a>] ? SYSC_kill+0xba/0x1d0 [<ffffffff811f2348>] ? __sb_end_write+0x58/0x80 [<ffffffff812258ac>] vfs_fsync_range+0x4c/0xb0 [<ffffffff81002501>] ? syscall_trace_enter+0x201/0x2e0 [<ffffffff8122592c>] vfs_fsync+0x1c/0x20 [<ffffffff8122596d>] do_fsync+0x3d/0x70 [<ffffffff810029cb>] ? syscall_slow_exit_work+0xfb/0x100 [<ffffffff812259d0>] SyS_fsync+0x10/0x20 [<ffffffff81002b65>] do_syscall_64+0x55/0xd0 [<ffffffff810026d7>] ? prepare_exit_to_usermode+0x37/0x40 [<ffffffff819ad246>] entry_SYSCALL64_slow_path+0x25/0x25 ---[ end trace efe6b17c6dba2a6e ]--- -- 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
