From: Ingo Molnar Date: Mon, 12 May 2008 19:20:46 +0000 (+0200) Subject: ftrace: fix locking X-Git-Tag: firefly_0821_release~19697^2^2~1^2~120 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d4c5a2f5870939d837293de87b41dda0012a4572;p=firefly-linux-kernel-4.4.55.git ftrace: fix locking we can hold all cpu trace buffer locks at once - put each into a separate lock class. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a40687a4413a..b3811ca74071 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1865,11 +1865,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, } - for_each_possible_cpu(cpu) { + for_each_cpu_mask(cpu, mask) { data = iter->tr->data[cpu]; - - if (!cpu_isset(cpu, mask)) - continue; spin_unlock(&data->lock); atomic_dec(&data->disabled); } @@ -2076,6 +2073,7 @@ static int trace_alloc_page(void) for_each_possible_cpu(i) { data = global_trace.data[i]; spin_lock_init(&data->lock); + lockdep_set_class(&data->lock, &data->lock_key); page = list_entry(pages.next, struct page, lru); list_del_init(&page->lru); list_add_tail(&page->lru, &data->trace_pages); @@ -2084,6 +2082,7 @@ static int trace_alloc_page(void) #ifdef CONFIG_TRACER_MAX_TRACE data = max_tr.data[i]; spin_lock_init(&data->lock); + lockdep_set_class(&data->lock, &data->lock_key); page = list_entry(pages.next, struct page, lru); list_del_init(&page->lru); list_add_tail(&page->lru, &data->trace_pages); @@ -2203,5 +2202,4 @@ __init static int tracer_alloc_buffers(void) } return ret; } - fs_initcall(tracer_alloc_buffers); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 29a7ea59de50..b0408356f0e0 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -56,6 +56,7 @@ struct trace_array_cpu { struct list_head trace_pages; atomic_t disabled; spinlock_t lock; + struct lock_class_key lock_key; cycle_t time_offset; /* these fields get copied into max-trace: */