On Mon, 26 Jan 2026 10:43:16 +0800 Yaxiong Tian <[email protected]> wrote:
Hi, Some of your terminology is a little confusing. The subject says "modules" but no module will use it (the term module means loadable code at runtime into the Linux kernel). A better subject would be: tracing: Rename `eval_map_wq` and allow other parts of tracing use it > 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 Also saying "export" for a function means something like "EXPORT_SYMBOLE()" which again deals with Linux modules. A better term is "make it global". > other modules to schedule work on this queue asynchronously and .. other parts of tracing .. > avoiding blockage of the main boot thread. > > Signed-off-by: Yaxiong Tian <[email protected]> Other than that, this patch looks good. -- Steve > --- > 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,
