The eval_map_work_func() function, though queued in eval_map_wq, holds the trace_event_sem read-write lock for a long time during kernel boot. This causes blocking issues for other functions.
Rename eval_map_wq to trace_init_wq and export it, thereby allowing other modules to schedule work on this queue asynchronously and avoiding blockage of the main boot thread. Signed-off-by: Yaxiong Tian <[email protected]> --- kernel/trace/trace.c | 18 +++++++++--------- kernel/trace/trace.h | 2 ++ 2 files changed, 11 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e18005807395..c61e30cb7339 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -10774,7 +10774,7 @@ int tracing_init_dentry(void) extern struct trace_eval_map *__start_ftrace_eval_maps[]; extern struct trace_eval_map *__stop_ftrace_eval_maps[]; -static struct workqueue_struct *eval_map_wq __initdata; +struct workqueue_struct *trace_init_wq __initdata; static struct work_struct eval_map_work __initdata; static struct work_struct tracerfs_init_work __initdata; @@ -10790,15 +10790,15 @@ static int __init trace_eval_init(void) { INIT_WORK(&eval_map_work, eval_map_work_func); - eval_map_wq = alloc_workqueue("eval_map_wq", WQ_UNBOUND, 0); - if (!eval_map_wq) { - pr_err("Unable to allocate eval_map_wq\n"); + trace_init_wq = alloc_workqueue("trace_init_wq", WQ_UNBOUND, 0); + if (!trace_init_wq) { + pr_err("Unable to allocate trace_init_wq\n"); /* Do work here */ eval_map_work_func(&eval_map_work); return -ENOMEM; } - queue_work(eval_map_wq, &eval_map_work); + queue_work(trace_init_wq, &eval_map_work); return 0; } @@ -10807,8 +10807,8 @@ subsys_initcall(trace_eval_init); static int __init trace_eval_sync(void) { /* Make sure the eval map updates are finished */ - if (eval_map_wq) - destroy_workqueue(eval_map_wq); + if (trace_init_wq) + destroy_workqueue(trace_init_wq); return 0; } @@ -10969,9 +10969,9 @@ static __init int tracer_init_tracefs(void) if (ret) return 0; - if (eval_map_wq) { + if (trace_init_wq) { INIT_WORK(&tracerfs_init_work, tracer_init_tracefs_work_func); - queue_work(eval_map_wq, &tracerfs_init_work); + queue_work(trace_init_wq, &tracerfs_init_work); } else { tracer_init_tracefs_work_func(NULL); } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index de4e6713b84e..e52f259f8945 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -770,6 +770,8 @@ extern unsigned long nsecs_to_usecs(unsigned long nsecs); extern unsigned long tracing_thresh; +extern struct workqueue_struct *trace_init_wq __initdata; + /* PID filtering */ bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids, -- 2.25.1
