Dear All, We are using 3.8.x kernel on ARM, We are facing soft lockup issue. Following are the logs.
BUG: spinlock lockup suspected on CPU#0, process1/525 lock: 0xd8ac9a64, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 1 . Looks like lock is available as owner is -1, why arch_spin_trylock is getting failed ? 2. There is a patch : ARM: spinlock: retry trylock operation if strex fails on free lock http://permalink.gmane.org/gmane.linux.ports.arm.kernel/240913 In this patch, A loop has been added around strexeq %2, %0, [%3]". {Comment "retry the trylock operation if the lock appears to be free but the strex reported failure"} but arch_spin_trylock is called by __spin_lock_debug and its already getting called in loops. So what purpose is resolves? static void __spin_lock_debug(raw_spinlock_t *lock) { u64 i; u64 loops = loops_per_jiffy * HZ; for (i = 0; i < loops; i++) { if (arch_spin_trylock(&lock->raw_lock)) return; __delay(1); } /* lockup suspected: */ spin_dump(lock, "lockup suspected"); } 3. Is this patch useful to us, How can we reproduce this scenario ? Scenario : Lock is available but arch_spin_trylock is returning as failure Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
