Hi Leo, There was no upstream commit ID here but I found it in mainline here : commit 109704492ef637956265ec2eb72ae7b3b39eb6f4 Author: Joel Fernandes <joelaf@xxxxxxxxxx> Date: Thu Oct 20 00:34:00 2016 -0700 pstore: Make spinlock per zone instead of global What worries me is that some later fixes were issued, apparently to fix an oops and a warning after this patch : commit 76d5692a58031696e282384cbd893832bc92bd76 Author: Kees Cook <keescook@xxxxxxxxxxxx> Date: Thu Feb 9 15:43:44 2017 -0800 pstore: Correctly initialize spinlock and flags The ram backend wasn't always initializing its spinlock correctly. Since it was coming from kzalloc memory, though, it was harmless on architectures that initialize unlocked spinlocks to 0 (at least x86 and ARM). This also fixes a possibly ignored flag setting too. and : commit e9a330c4289f2ba1ca4bf98c2b430ab165a8931b Author: Kees Cook <keescook@xxxxxxxxxxxx> Date: Sun Mar 5 22:08:58 2017 -0800 pstore: Use dynamic spinlock initializer The per-prz spinlock should be using the dynamic initializer so that lockdep can correctly track it. Without this, under lockdep, we get a warning at boot that the lock is in non-static memory. So I'm fine with merging this patch as long as Kees is OK with this and we know what exact patch series needs to be merged. Also, the information you added to the commit message references a trace on a 4.4 kernel. Do you confirm that you got the same issue on 3.10 ? I just prefer to avoid blindly backporting sensitive patches if they're not absolutely needed. > [ 65.103905] hrtimer: interrupt took 2759375 ns > [ 65.108721] BUG: spinlock recursion on CPU#0, kschedfreq:0/1246 > [ 65.108760] lock: buffer_lock+0x0/0x38, .magic: dead4ead, .owner: kschedfreq:0/1246, .owner_cpu: 0 > [ 65.108779] CPU: 0 PID: 1246 Comm: kschedfreq:0 Not tainted 4.4.74-07294-g5c996a9-dirty #130 Thanks! willy