| Message ID | 20240226032439.26359-1-qiang.zhang1211@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 043fc92b0161c2a0d7887b1d66dde85c1ae7dd6c |
| Headers | show |
| Series | rcu-tasks: Fix the comments for tasks_rcu_exit_srcu_stall_timer | expand |
> > The synchronize_srcu() has been removed by commit("rcu-tasks: Eliminate > deadlocks involving do_exit() and RCU tasks") in rcu_tasks_postscan. > This commit therefore fix the comments of tasks_rcu_exit_srcu_stall_timer. > > Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> > --- > kernel/rcu/tasks.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > index 78d74c81cc24..d5319bbe8c98 100644 > --- a/kernel/rcu/tasks.h > +++ b/kernel/rcu/tasks.h > @@ -150,7 +150,7 @@ static struct rcu_tasks rt_name = \ > > #ifdef CONFIG_TASKS_RCU > > -/* Report delay in synchronize_srcu() completion in rcu_tasks_postscan(). */ > +/* Report delay of scan exiting tasklist in rcu_tasks_postscan(). */ > static void tasks_rcu_exit_srcu_stall(struct timer_list *unused); > static DEFINE_TIMER(tasks_rcu_exit_srcu_stall_timer, tasks_rcu_exit_srcu_stall); Is this timer not necessary? any thoughts? Thanks Zqiang > #endif > -- > 2.17.1 >
On Mon, Feb 26, 2024 at 11:24:39AM +0800, Zqiang wrote: > The synchronize_srcu() has been removed by commit("rcu-tasks: Eliminate > deadlocks involving do_exit() and RCU tasks") in rcu_tasks_postscan. > This commit therefore fix the comments of tasks_rcu_exit_srcu_stall_timer. > > Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> Queued, most likely for the v6.10 merge window, thank you! Thanx, Paul > --- > kernel/rcu/tasks.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > index 78d74c81cc24..d5319bbe8c98 100644 > --- a/kernel/rcu/tasks.h > +++ b/kernel/rcu/tasks.h > @@ -150,7 +150,7 @@ static struct rcu_tasks rt_name = \ > > #ifdef CONFIG_TASKS_RCU > > -/* Report delay in synchronize_srcu() completion in rcu_tasks_postscan(). */ > +/* Report delay of scan exiting tasklist in rcu_tasks_postscan(). */ > static void tasks_rcu_exit_srcu_stall(struct timer_list *unused); > static DEFINE_TIMER(tasks_rcu_exit_srcu_stall_timer, tasks_rcu_exit_srcu_stall); > #endif > -- > 2.17.1 >
On Mon, Feb 26, 2024 at 11:28:57AM +0800, Z qiang wrote: > > > > The synchronize_srcu() has been removed by commit("rcu-tasks: Eliminate > > deadlocks involving do_exit() and RCU tasks") in rcu_tasks_postscan. > > This commit therefore fix the comments of tasks_rcu_exit_srcu_stall_timer. > > > > Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> > > --- > > kernel/rcu/tasks.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > > index 78d74c81cc24..d5319bbe8c98 100644 > > --- a/kernel/rcu/tasks.h > > +++ b/kernel/rcu/tasks.h > > @@ -150,7 +150,7 @@ static struct rcu_tasks rt_name = \ > > > > #ifdef CONFIG_TASKS_RCU > > > > -/* Report delay in synchronize_srcu() completion in rcu_tasks_postscan(). */ > > +/* Report delay of scan exiting tasklist in rcu_tasks_postscan(). */ > > static void tasks_rcu_exit_srcu_stall(struct timer_list *unused); > > static DEFINE_TIMER(tasks_rcu_exit_srcu_stall_timer, tasks_rcu_exit_srcu_stall); > > Is this timer not necessary? any thoughts? We have preemption points in the list traversals, and things like mutex contention on the do_exit() path could result in extremely long lists, so I believe we do need the timer. But what did you have in mind? Thanx, Paul > Thanks > Zqiang > > > > #endif > > -- > > 2.17.1 > >
> > On Mon, Feb 26, 2024 at 11:28:57AM +0800, Z qiang wrote: > > > > > > The synchronize_srcu() has been removed by commit("rcu-tasks: Eliminate > > > deadlocks involving do_exit() and RCU tasks") in rcu_tasks_postscan. > > > This commit therefore fix the comments of tasks_rcu_exit_srcu_stall_timer. > > > > > > Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> > > > --- > > > kernel/rcu/tasks.h | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > > > index 78d74c81cc24..d5319bbe8c98 100644 > > > --- a/kernel/rcu/tasks.h > > > +++ b/kernel/rcu/tasks.h > > > @@ -150,7 +150,7 @@ static struct rcu_tasks rt_name = \ > > > > > > #ifdef CONFIG_TASKS_RCU > > > > > > -/* Report delay in synchronize_srcu() completion in rcu_tasks_postscan(). */ > > > +/* Report delay of scan exiting tasklist in rcu_tasks_postscan(). */ > > > static void tasks_rcu_exit_srcu_stall(struct timer_list *unused); > > > static DEFINE_TIMER(tasks_rcu_exit_srcu_stall_timer, tasks_rcu_exit_srcu_stall); > > > > Is this timer not necessary? any thoughts? > > We have preemption points in the list traversals, and things like mutex > contention on the do_exit() path could result in extremely long lists, > so I believe we do need the timer. > > But what did you have in mind? Thanks for the explanation, I ignored the scenario where the lists might be very long :) Thanks Zqiang > > Thanx, Paul > > > Thanks > > Zqiang > > > > > > > #endif > > > -- > > > 2.17.1 > > >
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 78d74c81cc24..d5319bbe8c98 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -150,7 +150,7 @@ static struct rcu_tasks rt_name = \ #ifdef CONFIG_TASKS_RCU -/* Report delay in synchronize_srcu() completion in rcu_tasks_postscan(). */ +/* Report delay of scan exiting tasklist in rcu_tasks_postscan(). */ static void tasks_rcu_exit_srcu_stall(struct timer_list *unused); static DEFINE_TIMER(tasks_rcu_exit_srcu_stall_timer, tasks_rcu_exit_srcu_stall); #endif
The synchronize_srcu() has been removed by commit("rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks") in rcu_tasks_postscan. This commit therefore fix the comments of tasks_rcu_exit_srcu_stall_timer. Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> --- kernel/rcu/tasks.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)