trace_workqueue: remove cpu_workqueue_stats->first_entry

cpu_workqueue_stats->first_entry is useless because we can retrieve the
header of a cpu workqueue using:
if (&cpu_workqueue_stats->list == workqueue_cpu_stat(cpu)->list.next)

[ Impact: cleanup ]

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 0 insertions, 4 deletions

diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c
index 128b64b93f14..890974aed64d 100644
--- a/kernel/trace/trace_workqueue.c
+++ b/kernel/trace/trace_workqueue.c
@@ -16,8 +16,6 @@
 /* A cpu workqueue thread */
 struct cpu_workqueue_stats {
         struct list_head            list;
-/* Useful to know if we print the cpu headers */
-        bool                        first_entry;
         int                         cpu;
         pid_t                       pid;
 /* Can be inserted from interrupt or user context, need to be atomic */
@@ -103,8 +101,6 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu)
         cws->pid = wq_thread->pid;
 
         spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
-        if (list_empty(&workqueue_cpu_stat(cpu)->list))
-                cws->first_entry = true;
         list_add_tail(&cws->list, &workqueue_cpu_stat(cpu)->list);
         spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
 }