From dbf520a9d7d4d5ba28d2947be11e34099a5e3e20 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Sun, 31 Mar 2013 00:04:40 +0000 Subject: Revert "lockdep: check that no locks held at freeze time" This reverts commit 6aa9707099c4b25700940eb3d016f16c4434360d. Commit 6aa9707099c4 ("lockdep: check that no locks held at freeze time") causes problems with NFS root filesystems. The failures were noticed on OMAP2 and 3 boards during kernel init: [ BUG: swapper/0/1 still has locks held! ] 3.9.0-rc3-00344-ga937536 #1 Not tainted ------------------------------------- 1 lock held by swapper/0/1: #0: (&type->s_umount_key#13/1){+.+.+.}, at: [] sget+0x248/0x574 stack backtrace: rpc_wait_bit_killable __wait_on_bit out_of_line_wait_on_bit __rpc_execute rpc_run_task rpc_call_sync nfs_proc_get_root nfs_get_root nfs_fs_mount_common nfs_try_mount nfs_fs_mount mount_fs vfs_kern_mount do_mount sys_mount do_mount_root mount_root prepare_namespace kernel_init_freeable kernel_init Although the rootfs mounts, the system is unstable. Here's a transcript from a PM test: http://www.pwsan.com/omap/testlogs/test_v3.9-rc3/20130317194234/pm/37xxevm/37xxevm_log.txt Here's what the test log should look like: http://www.pwsan.com/omap/testlogs/test_v3.8/20130218214403/pm/37xxevm/37xxevm_log.txt Mailing list discussion is here: http://lkml.org/lkml/2013/3/4/221 Deal with this for v3.9 by reverting the problem commit, until folks can figure out the right long-term course of action. Signed-off-by: Paul Walmsley Cc: Mandeep Singh Baines Cc: Jeff Layton Cc: Shawn Guo Cc: Cc: Fengguang Wu Cc: Trond Myklebust Cc: Ingo Molnar Cc: Ben Chan Cc: Oleg Nesterov Cc: Tejun Heo Cc: Rafael J. Wysocki Cc: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/debug_locks.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/debug_locks.h') diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h index a975de1ff59f..3bd46f766751 100644 --- a/include/linux/debug_locks.h +++ b/include/linux/debug_locks.h @@ -51,7 +51,7 @@ struct task_struct; extern void debug_show_all_locks(void); extern void debug_show_held_locks(struct task_struct *task); extern void debug_check_no_locks_freed(const void *from, unsigned long len); -extern void debug_check_no_locks_held(void); +extern void debug_check_no_locks_held(struct task_struct *task); #else static inline void debug_show_all_locks(void) { @@ -67,7 +67,7 @@ debug_check_no_locks_freed(const void *from, unsigned long len) } static inline void -debug_check_no_locks_held(void) +debug_check_no_locks_held(struct task_struct *task) { } #endif -- cgit v1.2.2 From 2c2fea11957c8c45bf873d9bcd7cd9a342654e79 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 29 Apr 2013 15:06:06 -0700 Subject: debug_locks.h: make warning more verbose The WARN_ON(1) in DEBUG_LOCKS_WARN_ON is surprisingly awkward to track down when it's hit, as it's usually buried in macros, causing multiple instances to land on the same line number. This patch makes it more useful by switching to: WARN(1, "DEBUG_LOCKS_WARN_ON(%s)", #c); so that the particular DEBUG_LOCKS_WARN_ON is more easily identified and grep'd for. For example: WARNING: at kernel/mutex.c:198 _mutex_lock_nested+0x31c/0x380() DEBUG_LOCKS_WARN_ON(l->magic != l) Signed-off-by: James Hogan Cc: Paul Gortmaker Cc: David Howells Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/debug_locks.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/debug_locks.h') diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h index 3bd46f766751..21ca773f77bf 100644 --- a/include/linux/debug_locks.h +++ b/include/linux/debug_locks.h @@ -27,7 +27,7 @@ extern int debug_locks_off(void); \ if (!oops_in_progress && unlikely(c)) { \ if (debug_locks_off() && !debug_locks_silent) \ - WARN_ON(1); \ + WARN(1, "DEBUG_LOCKS_WARN_ON(%s)", #c); \ __ret = 1; \ } \ __ret; \ -- cgit v1.2.2