rcu: enable rcu_normal_after_boot by default for RT
Paul E. McKenney
Acked-byQuoted 10 lines
The forcing of an expedited grace period is an expensive and very RT-application unfriendly operation, as it forcibly preempts all running tasks on CPUs which are preventing the gp from expiring.
By default, as a policy decision, disable the expediting of grace periods (after boot) on configurations which enable
PREEMPT_RT_FULL.Suggested-by Luiz Capitulino <[email protected]>Signed-off-by Julia Cartwright <[email protected]>Signed-off-by Sebastian Andrzej Siewior <[email protected]>
In case it matters:
Alternatively, any reason that I should not pull this into -rcu?
Thanx, Paul
Quoted 13 lines
kernel/rcu/update.c +1
-1@@ -67,7 +67,7 @@ extern int rcu_expedited; /* from sysctl */module_param (rcu_expedited, int,0 );extern int rcu_normal;/* from sysctl */ module_param (rcu_normal, int,0 ); -static int rcu_normal_after_boot; +static int rcu_normal_after_boot =IS_ENABLED (CONFIG_PREEMPT_RT_FULL );module_param (rcu_normal_after_boot, int,0 );#endif /* #ifndef CONFIG_TINY_RCU */
Quoted 11 lines · Paul E. McKenney
Quoted 10 lines
The forcing of an expedited grace period is an expensive and very RT-application unfriendly operation, as it forcibly preempts all running tasks on CPUs which are preventing the gp from expiring.
By default, as a policy decision, disable the expediting of grace periods (after boot) on configurations which enable
PREEMPT_RT_FULL.Suggested-by Luiz Capitulino <[email protected]>Signed-off-by Julia Cartwright <[email protected]>Signed-off-by Sebastian Andrzej Siewior <[email protected]>
Quoted 5 lines
In case it matters:
Acked-by Paul E. McKenney <[email protected]>Alternatively, any reason that I should not pull this into -rcu?
because we don't have CONFIG_PREEMPT_RT_FULL yet.
Quoted 1 line
Thanx, Paul
Sebastian
Quoted 12 lines · Sebastian Andrzej Siewior
Quoted 11 lines · Paul E. McKenney
Quoted 10 lines
The forcing of an expedited grace period is an expensive and very RT-application unfriendly operation, as it forcibly preempts all running tasks on CPUs which are preventing the gp from expiring.
By default, as a policy decision, disable the expediting of grace periods (after boot) on configurations which enable
PREEMPT_RT_FULL.Suggested-by Luiz Capitulino <[email protected]>Signed-off-by Julia Cartwright <[email protected]>Signed-off-by Sebastian Andrzej Siewior <[email protected]>
Quoted 7 lines
Quoted 5 lines
In case it matters:
Acked-by Paul E. McKenney <[email protected]>Alternatively, any reason that I should not pull this into -rcu?
because we don't have
CONFIG_PREEMPT_RT_FULLyet.
Fair enough. This particular case works without CONFIG_PREEMPT_RT_FULL defined, but up to you guys.
Thanx, Paul