With -next 20110113 I'm experiencing lockups shortly after userspace starts when booting with my root filesystem on NFS, log below. I can boot into /bin/sh but running real userspace triggers this very easily. This was introduced sometime this week. I've not bisected or otherwise investigated much yet, but I do notice code added recently by Nick in "fs: rcu-walk for path lookup" showing up in the backtrace so including him in the CCs. Tail of the console log: INIT: version 2.86 booting [ 15.250000] BUG: spinlock recursion on CPU#0, rc/1151 [ 15.250000] lock: c74ad678, .magic: dead4ead, .owner: rc/1151, .owner_cpu: 0 [ 15.260000] [<c0035118>] (unwind_backtrace+0x0/0xe4) from [<c0190454>] (do_raw_spin_lock+0x48/0x148) [ 15.260000] [<c0190454>] (do_raw_spin_lock+0x48/0x148) from [<c00c89f0>] (nameidata_dentry_drop_rcu+0x84/0x180) [ 15.270000] [<c00c89f0>] (nameidata_dentry_drop_rcu+0x84/0x180) from [<c00c8b1c>] (d_revalidate+0x30/0x58) [ 15.280000] [<c00c8b1c>] (d_revalidate+0x30/0x58) from [<c00cb82c>] (link_path_walk+0xad8/0xb00) [ 15.290000] [<c00cb82c>] (link_path_walk+0xad8/0xb00) from [<c00cba4c>] (do_path_lookup+0x44/0xcc) [ 15.300000] [<c00cba4c>] (do_path_lookup+0x44/0xcc) from [<c00cc3f4>] (user_path_at+0x58/0x90) [ 15.310000] [<c00cc3f4>] (user_path_at+0x58/0x90) from [<c00c4210>] (vfs_fstatat+0x28/0x54) [ 15.320000] [<c00c4210>] (vfs_fstatat+0x28/0x54) from [<c00c431c>] (sys_stat64+0x14/0x34) [ 15.330000] [<c00c431c>] (sys_stat64+0x14/0x34) from [<c002f4e0>] (ret_fast_syscall+0x0/0x30) [ 25.830000] BUG: spinlock lockup on CPU#0, rc/1151, c74ad678 [ 25.830000] [<c0035118>] (unwind_backtrace+0x0/0xe4) from [<c0190518>] (do_raw_spin_lock+0x10c/0x148) [ 25.840000] [<c0190518>] (do_raw_spin_lock+0x10c/0x148) from [<c00c89f0>] (nameidata_dentry_drop_rcu+0x84/0x180) [ 25.850000] [<c00c89f0>] (nameidata_dentry_drop_rcu+0x84/0x180) from [<c00c8b1c>] (d_revalidate+0x30/0x58) [ 25.860000] [<c00c8b1c>] (d_revalidate+0x30/0x58) from [<c00cb82c>] (link_path_walk+0xad8/0xb00) [ 25.870000] [<c00cb82c>] (link_path_walk+0xad8/0xb00) from [<c00cba4c>] (do_path_lookup+0x44/0xcc) [ 25.870000] [<c00cba4c>] (do_path_lookup+0x44/0xcc) from [<c00cc3f4>] (user_path_at+0x58/0x90) [ 25.880000] [<c00cc3f4>] (user_path_at+0x58/0x90) from [<c00c4210>] (vfs_fstatat+0x28/0x54) [ 25.890000] [<c00c4210>] (vfs_fstatat+0x28/0x54) from [<c00c431c>] (sys_stat64+0x14/0x34) [ 25.900000] [<c00c431c>] (sys_stat64+0x14/0x34) from [<c002f4e0>] (ret_fast_syscall+0x0/0x30) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html