From: Thomas Gleixner On RT we avoid the cross cpu function calls and take the per cpu local locks instead. Now the code missed that taking the local lock on the cpu which runs the code must use the proper local lock functions and not a simple spin_lock(). Otherwise it deadlocks later when trying to acquire the local lock with the proper function. Reported-and-tested-by: Chris Pringle Signed-off-by: Thomas Gleixner Signed-off-by: Steven Rostedt --- mm/slab.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 15bce6b..64eb636 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -743,8 +743,26 @@ slab_on_each_cpu(void (*func)(void *arg, int this_cpu), void *arg) { unsigned int i; + get_cpu_light(); for_each_online_cpu(i) func(arg, i); + put_cpu_light(); +} + +static void lock_slab_on(unsigned int cpu) +{ + if (cpu == smp_processor_id()) + local_lock_irq(slab_lock); + else + local_spin_lock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock); +} + +static void unlock_slab_on(unsigned int cpu) +{ + if (cpu == smp_processor_id()) + local_unlock_irq(slab_lock); + else + local_spin_unlock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock); } #endif @@ -2692,10 +2710,10 @@ static void do_drain(void *arg, int cpu) { LIST_HEAD(tmp); - spin_lock_irq(&per_cpu(slab_lock, cpu).lock); + lock_slab_on(cpu); __do_drain(arg, cpu); list_splice_init(&per_cpu(slab_free_list, cpu), &tmp); - spin_unlock_irq(&per_cpu(slab_lock, cpu).lock); + unlock_slab_on(cpu); free_delayed(&tmp); } #endif @@ -4163,9 +4181,9 @@ static void do_ccupdate_local(void *info) #else static void do_ccupdate_local(void *info, int cpu) { - spin_lock_irq(&per_cpu(slab_lock, cpu).lock); + lock_slab_on(cpu); __do_ccupdate_local(info, cpu); - spin_unlock_irq(&per_cpu(slab_lock, cpu).lock); + unlock_slab_on(cpu); } #endif -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/