Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1251183

Re: [PATCH] posix-cpu-timers: Merge running and checking_timer state in one field

Show all headers | View raw

On Tue, 20 Oct 2015, Frederic Weisbecker wrote:

>- * @checking_timer:	true when a thread in the group is in the
>- *			process of checking for thread group timers.
>- *
>+ * @state:		flags describing the current state of the cputimer.
>+ *			CPUTIMER_STATE_RUNNING bit means the timers is elapsing.

                                                              s/timers/timer

>+ * 			CPUTIMER_STATE_CHECKING bit means that the cputimer has
>+ *			expired and a thread in the group is checking the
>+ *			callback list.

These comments might be better served when defining CPUTIMER_STATE_*

[...]

>@@ -606,7 +606,7 @@ bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
> 		return false;
>
> 	/* Check if cputimer is running. This is accessed without locking. */
>-	if (READ_ONCE(tsk->signal->cputimer.running))
>+	if (READ_ONCE(tsk->signal->cputimer.state))
> 		return false;

Could we have cases, such as the above, where .state is set to CPUTIMER_STATE_CHECKING
and therefore the check is not equivalent?

Thanks,
Davidlohr
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] posix-cpu-timers: Merge running and checking_timer state in one field Frederic Weisbecker <fweisbec@gmail.com> - 2015-10-20 02:20 +0200
  Re: [PATCH] posix-cpu-timers: Merge running and checking_timer state  in one field Davidlohr Bueso <dave@stgolabs.net> - 2015-10-20 02:50 +0200
    Re: [PATCH] posix-cpu-timers: Merge running and checking_timer state  in one field Frederic Weisbecker <fweisbec@gmail.com> - 2015-10-20 03:00 +0200
  Re: [PATCH] posix-cpu-timers: Merge running and checking_timer  state in one field Jason Low <jason.low@hpe.com> - 2015-10-20 20:20 +0200

csiph-web