diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2012-10-09 18:35:22 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2012-10-09 18:35:22 -0400 |
| commit | f474af7051212b4efc8267583fad9c4ebf33ccff (patch) | |
| tree | 1aa46ebc8065a341f247c2a2d9af2f624ad1d4f8 /lib/spinlock_debug.c | |
| parent | 0d22f68f02c10d5d10ec5712917e5828b001a822 (diff) | |
| parent | e3dd9a52cb5552c46c2a4ca7ccdfb4dab5c72457 (diff) | |
nfs: disintegrate UAPI for nfs
This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently. After these patches, userspace
headers will be segregated into:
include/uapi/linux/.../foo.h
for the userspace interface stuff, and:
include/linux/.../foo.h
for the strictly kernel internal stuff.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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 eb10578ae05..0374a596cff 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) |