From mboxrd@z Thu Jan 1 00:00:00 1970 From: shc_work@mail.ru (=?UTF-8?B?QWxleGFuZGVyIFNoaXlhbg==?=) Date: Mon, 12 May 2014 00:22:34 +0400 Subject: =?UTF-8?B?UmU6IG14cy1kY3A6IEJVRzogaW5pdC8xIHN0aWxsIGhhcyBsb2NrcyBoZWxk?= =?UTF-8?B?IQ==?= In-Reply-To: References: <1399838888.578955384@f427.i.mail.ru> Message-ID: <1399839754.36608614@f427.i.mail.ru> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Sun, 11 May 2014 17:09:27 -0300 ?? Fabio Estevam : > On Sun, May 11, 2014 at 5:08 PM, Alexander Shiyan wrote: > > Sun, 11 May 2014 16:57:57 -0300 ?? Fabio Estevam : > >> Hi, > >> > >> Running linux-next 20140509 on a mx28evk I observe the following warning: > >> > >> [ 8.526613] Freeing unused kernel memory: 232K (c0683000 - c06bd000) > >> starting pid 56, tty '': '/etc/rc.d/rcS' > >> [ 9.110314] > >> [ 9.111864] ===================================== > >> [ 9.116603] [ BUG: init/1 still has locks held! ] > >> [ 9.121488] 3.15.0-rc4-next-20140509-00001-g319564e #1154 Not tainted > >> [ 9.128071] ------------------------------------- > >> [ 9.132825] 1 lock held by init/1: > >> [ 9.136252] #0: (global_mutex){+.+.+.}, at: [] mxs_dcp_probe+0x14 > >> [ 9.144196] > >> [ 9.144196] stack backtrace: > >> [ 9.148888] CPU: 0 PID: 1 Comm: init Not tainted 3.15.0-rc4-next-20140509-004 > >> [ 9.157610] [] (unwind_backtrace) from [] (show_stack+0x) > >> [ 9.165595] [] (show_stack) from [] (do_fork+0x2c8/0x3cc) > >> [ 9.172921] [] (do_fork) from [] (sys_vfork+0x20/0x2c) > >> [ 9.179973] [] (sys_vfork) from [] (ret_fast_syscall+0x0) > >> Mounting /proc and /sys > >> > >> Should we really use a global mutex here? What is a proper fix for this? > > > > On my opinion mutex_lock/unlock should not be used in probe. > > Try to remove this entirely. > > I think the same. Will submit a patch doing as suggested. AFAIK, probe/remove are serialized and running only on one CPU/thread, so any mutexes/spinlocks really not needed. 2ML: Please, FIXME if I am think incorrect. ---