Re: [PATCH tip/core/rcu 2/2] rcu: Allow TREE_PREEMPT_RCU on UP systems
On Sat, Jan 26, 2013 at 04:23:47PM -0800, Paul E. McKenney wrote: > From: "Paul E. McKenney" > > The TINY_PREEMPT_RCU is complex, does not provide that much memory > savings, and therefore TREE_PREEMPT_RCU should be used instead. The > systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU > are quite small compared to the memory footprint of CONFIG_PREEMPT. > > This commit therefore takes a first step towards eliminating > TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP > systems. > > Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett > --- > init/Kconfig |4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/init/Kconfig b/init/Kconfig > index a5e90e1..fb19b46 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -453,7 +453,7 @@ config TREE_RCU > > config TREE_PREEMPT_RCU > bool "Preemptible tree-based hierarchical RCU" > - depends on PREEMPT && SMP > + depends on PREEMPT > help > This option selects the RCU implementation that is > designed for very large SMP systems with hundreds or > @@ -461,6 +461,8 @@ config TREE_PREEMPT_RCU > is also required. It also scales down nicely to > smaller systems. > > + Select this option if you are unsure. > + > config TINY_RCU > bool "UP-only small-memory-footprint RCU" > depends on !PREEMPT && !SMP > -- > 1.7.8 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH tip/core/rcu 2/2] rcu: Allow TREE_PREEMPT_RCU on UP systems
On Sat, Jan 26, 2013 at 04:23:47PM -0800, Paul E. McKenney wrote: From: Paul E. McKenney paul...@linux.vnet.ibm.com The TINY_PREEMPT_RCU is complex, does not provide that much memory savings, and therefore TREE_PREEMPT_RCU should be used instead. The systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU are quite small compared to the memory footprint of CONFIG_PREEMPT. This commit therefore takes a first step towards eliminating TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP systems. Signed-off-by: Paul E. McKenney paul...@linux.vnet.ibm.com Reviewed-by: Josh Triplett j...@joshtriplett.org --- init/Kconfig |4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index a5e90e1..fb19b46 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -453,7 +453,7 @@ config TREE_RCU config TREE_PREEMPT_RCU bool Preemptible tree-based hierarchical RCU - depends on PREEMPT SMP + depends on PREEMPT help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or @@ -461,6 +461,8 @@ config TREE_PREEMPT_RCU is also required. It also scales down nicely to smaller systems. + Select this option if you are unsure. + config TINY_RCU bool UP-only small-memory-footprint RCU depends on !PREEMPT !SMP -- 1.7.8 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH tip/core/rcu 2/2] rcu: Allow TREE_PREEMPT_RCU on UP systems
From: "Paul E. McKenney" The TINY_PREEMPT_RCU is complex, does not provide that much memory savings, and therefore TREE_PREEMPT_RCU should be used instead. The systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU are quite small compared to the memory footprint of CONFIG_PREEMPT. This commit therefore takes a first step towards eliminating TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP systems. Signed-off-by: Paul E. McKenney --- init/Kconfig |4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index a5e90e1..fb19b46 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -453,7 +453,7 @@ config TREE_RCU config TREE_PREEMPT_RCU bool "Preemptible tree-based hierarchical RCU" - depends on PREEMPT && SMP + depends on PREEMPT help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or @@ -461,6 +461,8 @@ config TREE_PREEMPT_RCU is also required. It also scales down nicely to smaller systems. + Select this option if you are unsure. + config TINY_RCU bool "UP-only small-memory-footprint RCU" depends on !PREEMPT && !SMP -- 1.7.8 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH tip/core/rcu 2/2] rcu: Allow TREE_PREEMPT_RCU on UP systems
From: Paul E. McKenney paul...@linux.vnet.ibm.com The TINY_PREEMPT_RCU is complex, does not provide that much memory savings, and therefore TREE_PREEMPT_RCU should be used instead. The systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU are quite small compared to the memory footprint of CONFIG_PREEMPT. This commit therefore takes a first step towards eliminating TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP systems. Signed-off-by: Paul E. McKenney paul...@linux.vnet.ibm.com --- init/Kconfig |4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index a5e90e1..fb19b46 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -453,7 +453,7 @@ config TREE_RCU config TREE_PREEMPT_RCU bool Preemptible tree-based hierarchical RCU - depends on PREEMPT SMP + depends on PREEMPT help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or @@ -461,6 +461,8 @@ config TREE_PREEMPT_RCU is also required. It also scales down nicely to smaller systems. + Select this option if you are unsure. + config TINY_RCU bool UP-only small-memory-footprint RCU depends on !PREEMPT !SMP -- 1.7.8 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
