Re: [for-next][PATCH 4/5] tracing: Check all tasks on each CPU when filtering pids

From: Steven Rostedt
Date: Fri Oct 30 2015 - 16:28:53 EST


On Fri, 30 Oct 2015 14:16:43 +0800
Jiaxing Wang <hello.wjx@xxxxxxxxx> wrote:

> On Thu, Oct 29, 2015 at 03:07:58AM -0400, Steven Rostedt wrote:
> > static ssize_t
> > ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
> > size_t cnt, loff_t *ppos)
> > @@ -1711,6 +1727,12 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
> > tr, INT_MAX);
> > register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
> > tr, 0);
> > +
> > + /*
> > + * Ignoring of pids is done at task switch. But we have to
> > + * check for those tasks that are currently running.
> > + */
> > + on_each_cpu(ignore_task_cpu, tr, 1);
> > }
> on_each_cpu(ignore_task_cpu, tr, 1); can be put outside of the else
> block, then ignore_pid can be updated when appending pid,
> eg. echo 'xxx' >> set_event_pid, in case xxx is running on some cpu.

Hmm, I guess I could.

-- Steve

> >
> > mutex_unlock(&event_mutex);

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