From bd220b212fde1e6771dcff5ee9de23d6eb1e8f08 Mon Sep 17 00:00:00 2001 From: Liam Girdwood Date: Tue, 19 Dec 2017 16:45:44 +0000 Subject: [PATCH] lock: Add deadlock detection. Add a debug option that can detect deadlock and panic(). The deadlock detection attempts to acquire a lock several times before giving up and causing a panic() taht dumps the deadlock details. Signed-off-by: Liam Girdwwod --- src/include/reef/debug.h | 1 + src/include/reef/lock.h | 71 +++++++++++++++++++++++++++++++--------- 2 files changed, 57 insertions(+), 15 deletions(-) diff --git a/src/include/reef/debug.h b/src/include/reef/debug.h index 70a78022f..7551fc5cb 100644 --- a/src/include/reef/debug.h +++ b/src/include/reef/debug.h @@ -45,6 +45,7 @@ #define PANIC_PLATFORM 4 #define PANIC_TASK 5 #define PANIC_EXCEPTION 6 +#define PANIC_DEADLOCK 7 #define DEBUG diff --git a/src/include/reef/lock.h b/src/include/reef/lock.h index deb0fb7c2..fd415aed5 100644 --- a/src/include/reef/lock.h +++ b/src/include/reef/lock.h @@ -35,6 +35,7 @@ #define __INCLUDE_LOCK__ #define DEBUG_LOCKS 0 +#define DEBUG_LOCKS_VERBOSE 0 #include #include @@ -62,19 +63,33 @@ * grep -rn lock --include *.c | grep 439 * src/lib/alloc.c:439: spin_lock_irq(&memmap.lock, flags); * - * Every lock entry and exit shows LcE and LcX in trace alonside the lock + * Every lock entry and exit shows LcE and LcX in trace alongside the lock * line numbers in hex. e.g. * * 0xfd60 [11032.730567] delta [0.000004] lock LcE * 0xfd70 [11032.730569] delta [0.000002] value 0x00000000000000ae * - * Deadlock would be a LcE without a subsequent LcX. + * Deadlock can be confirmed in rmbox :- * + * Debug log: + * debug: 0x0 (00) = 0xdead0007 (-559087609) |....| + * .... + * Error log: + * using 19.20MHz timestamp clock + * 0xc30 [26.247240] delta [26.245851] lock DED + * 0xc40 [26.247242] delta [0.000002] value 0x00000000000002b4 + * 0xc50 [26.247244] delta [0.000002] value 0x0000000000000109 + * + * DED means deadlock has been detected and the DSP is now halted. The first + * value after DEA is the line number where deadlock occurs and the second + * number is the line number where the lock is allocated. These can be grepped + * like above. */ #if DEBUG_LOCKS #define DBG_LOCK_USERS 8 +#define DBG_LOCK_TRIES 10000 #define trace_lock(__e) trace_error_atomic(TRACE_CLASS_LOCK, __e) #define tracev_lock(__e) tracev_event_atomic(TRACE_CLASS_LOCK, __e) @@ -84,22 +99,29 @@ extern uint32_t lock_dbg_atomic; extern uint32_t lock_dbg_user[DBG_LOCK_USERS]; -#define spin_lock_dbg() \ - trace_lock("LcE"); \ - trace_lock_value(__LINE__); - -#define spin_unlock_dbg() \ - trace_lock("LcX"); \ - trace_lock_value(__LINE__); \ - /* all SMP spinlocks need init, nothing todo on UP */ #define spinlock_init(lock) \ arch_spinlock_init(lock); \ (lock)->user = __LINE__; -/* does nothing on UP systems */ -#define spin_lock(lock) \ - spin_lock_dbg(); \ +/* panic on deadlock */ +#define spin_try_lock_dbg(lock) \ + do { \ + int __tries; \ + for (__tries = DBG_LOCK_TRIES; __tries > 0; __tries--) { \ + if (arch_try_lock(lock)) \ + break; /* lock acquired */ \ + } \ + if (__tries == 0) { \ + trace_lock_error("DED"); \ + trace_lock_value(__LINE__); \ + trace_lock_value((lock)->user); \ + panic(PANIC_DEADLOCK); /* lock not acquired */ \ + } \ + } while (0); + +#if DEBUG_LOCKS_VERBOSE +#define spin_lock_log(lock) \ if (lock_dbg_atomic) { \ int __i = 0; \ int __count = lock_dbg_atomic >= DBG_LOCK_USERS \ @@ -111,8 +133,27 @@ extern uint32_t lock_dbg_user[DBG_LOCK_USERS]; trace_lock_value((lock_dbg_atomic << 24) | \ lock_dbg_user[__i]); \ } \ - } \ - arch_spin_lock(lock); + } + +#define spin_lock_dbg() \ + trace_lock("LcE"); \ + trace_lock_value(__LINE__); + +#define spin_unlock_dbg() \ + trace_lock("LcX"); \ + trace_lock_value(__LINE__); + +#else +#define spin_lock_log(lock) +#define spin_lock_dbg() +#define spin_unlock_dbg() +#endif + +/* does nothing on UP systems */ +#define spin_lock(lock) \ + spin_lock_dbg(); \ + spin_lock_log(lock); \ + spin_try_lock_dbg(lock); #define spin_unlock(lock) \ arch_spin_unlock(lock); \