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| author |   Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2012-10-30 00:09:18 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2012-10-30 00:09:18 -0700 |
| commit | 68fe0f0a6dcd2ac1ace5da3647a6d1cf0f4d2fea (patch) | |
| tree | 69d855c2e46d42ef8f23680cf3a1e6ff38de9ef4 /lib/spinlock_debug.c | |
| parent | Input: wacom - add INPUT_PROP_DIRECT flag to Cintiq 24HD (diff) | |
| parent | Linux 3.7-rc3 (diff) | |
| download | linux-dev-68fe0f0a6dcd2ac1ace5da3647a6d1cf0f4d2fea.tar.xz linux-dev-68fe0f0a6dcd2ac1ace5da3647a6d1cf0f4d2fea.zip | |
Merge tag 'v3.7-rc3' into for-linus to sync up with recent USB changes
Diffstat (limited to 'lib/spinlock_debug.c')
| -rw-r--r-- | lib/spinlock_debug.c | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c index eb10578ae055..0374a596cffa 100644 --- a/lib/spinlock_debug.c +++ b/lib/spinlock_debug.c @@ -107,23 +107,27 @@ static void __spin_lock_debug(raw_spinlock_t *lock) { u64 i; u64 loops = loops_per_jiffy * HZ; - int print_once = 1; - for (;;) { - for (i = 0; i < loops; i++) { - if (arch_spin_trylock(&lock->raw_lock)) - return; - __delay(1); - } - /* lockup suspected: */ - if (print_once) { - print_once = 0; - spin_dump(lock, "lockup suspected"); + for (i = 0; i < loops; i++) { + if (arch_spin_trylock(&lock->raw_lock)) + return; + __delay(1); + } + /* lockup suspected: */ + spin_dump(lock, "lockup suspected"); #ifdef CONFIG_SMP - trigger_all_cpu_backtrace(); + trigger_all_cpu_backtrace(); #endif - } - } + + /* + * The trylock above was causing a livelock. Give the lower level arch + * specific lock code a chance to acquire the lock. We have already + * printed a warning/backtrace at this point. The non-debug arch + * specific code might actually succeed in acquiring the lock. If it is + * not successful, the end-result is the same - there is no forward + * progress. + */ + arch_spin_lock(&lock->raw_lock); } void do_raw_spin_lock(raw_spinlock_t *lock) |