aboutsummaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorOleg Nesterov <oleg@tv-sign.ru>2008-04-04 14:54:10 -0400
committerThomas Gleixner <tglx@linutronix.de>2008-04-17 06:22:31 -0400
commit0d180406f2914aea3a78ddb880e2fe9ac78a9372 (patch)
treedeb1f21d29a3ba8e7bdcc186ea78594599fce409 /kernel
parentee7dd205b5cdbc3231d48e38641efd05f572c52a (diff)
timers: simplify lockdep handling
In order to avoid the false positive from lockdep, each per-cpu base->lock has the separate lock class and migrate_timers() uses double_spin_lock(). This all is overcomplicated: except for migrate_timers() we never take 2 locks at once, and migrate_timers() can use spin_lock_nested(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/timer.c16
1 files changed, 4 insertions, 12 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index b024106daa70..f3d35d4ea42e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1228,13 +1228,6 @@ asmlinkage long sys_sysinfo(struct sysinfo __user *info)
1228 return 0; 1228 return 0;
1229} 1229}
1230 1230
1231/*
1232 * lockdep: we want to track each per-CPU base as a separate lock-class,
1233 * but timer-bases are kmalloc()-ed, so we need to attach separate
1234 * keys to them:
1235 */
1236static struct lock_class_key base_lock_keys[NR_CPUS];
1237
1238static int __cpuinit init_timers_cpu(int cpu) 1231static int __cpuinit init_timers_cpu(int cpu)
1239{ 1232{
1240 int j; 1233 int j;
@@ -1277,7 +1270,6 @@ static int __cpuinit init_timers_cpu(int cpu)
1277 } 1270 }
1278 1271
1279 spin_lock_init(&base->lock); 1272 spin_lock_init(&base->lock);
1280 lockdep_set_class(&base->lock, base_lock_keys + cpu);
1281 1273
1282 for (j = 0; j < TVN_SIZE; j++) { 1274 for (j = 0; j < TVN_SIZE; j++) {
1283 INIT_LIST_HEAD(base->tv5.vec + j); 1275 INIT_LIST_HEAD(base->tv5.vec + j);
@@ -1316,8 +1308,8 @@ static void __cpuinit migrate_timers(int cpu)
1316 new_base = get_cpu_var(tvec_bases); 1308 new_base = get_cpu_var(tvec_bases);
1317 1309
1318 local_irq_disable(); 1310 local_irq_disable();
1319 double_spin_lock(&new_base->lock, &old_base->lock, 1311 spin_lock(&new_base->lock);
1320 smp_processor_id() < cpu); 1312 spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1321 1313
1322 BUG_ON(old_base->running_timer); 1314 BUG_ON(old_base->running_timer);
1323 1315
@@ -1330,8 +1322,8 @@ static void __cpuinit migrate_timers(int cpu)
1330 migrate_timer_list(new_base, old_base->tv5.vec + i); 1322 migrate_timer_list(new_base, old_base->tv5.vec + i);
1331 } 1323 }
1332 1324
1333 double_spin_unlock(&new_base->lock, &old_base->lock, 1325 spin_unlock(&old_base->lock);
1334 smp_processor_id() < cpu); 1326 spin_unlock(&new_base->lock);
1335 local_irq_enable(); 1327 local_irq_enable();
1336 put_cpu_var(tvec_bases); 1328 put_cpu_var(tvec_bases);
1337} 1329}