From 2b1d5024e17be459aa6385763ca3faa8f01c52d9 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 11 Jul 2012 20:26:30 +0200 Subject: rcu: Settle config for userspace extended quiescent state Create a new config option under the RCU menu that put CPUs under RCU extended quiescent state (as in dynticks idle mode) when they run in userspace. This require some contribution from architectures to hook into kernel and userspace boundaries. Signed-off-by: Frederic Weisbecker Cc: Alessio Igor Bogani Cc: Andrew Morton Cc: Avi Kivity Cc: Chris Metcalf Cc: Christoph Lameter Cc: Geoff Levand Cc: Gilad Ben Yossef Cc: Hakan Akkan Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Josh Triplett Cc: Kevin Hilman Cc: Max Krasnyansky Cc: Peter Zijlstra Cc: Stephen Hemminger Cc: Steven Rostedt Cc: Sven-Thorsten Dietrich Cc: Thomas Gleixner Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- init/Kconfig | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'init/Kconfig') diff --git a/init/Kconfig b/init/Kconfig index af6c7f8ba019..f6a1830165ce 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -441,6 +441,16 @@ config PREEMPT_RCU This option enables preemptible-RCU code that is common between the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations. +config RCU_USER_QS + bool "Consider userspace as in RCU extended quiescent state" + depends on HAVE_RCU_USER_QS && SMP + help + This option sets hooks on kernel / userspace boundaries and + puts RCU in extended quiescent state when the CPU runs in + userspace. It means that when a CPU runs in userspace, it is + excluded from the global RCU state machine and thus doesn't + to keep the timer tick on for RCU. + config RCU_FANOUT int "Tree-based hierarchical RCU fanout value" range 2 64 if 64BIT -- cgit v1.2.3 From 1fd2b4425a5702c112b441e20b250ac8833a9608 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 11 Jul 2012 20:26:40 +0200 Subject: rcu: Userspace RCU extended QS selftest Provide a config option that enables the userspace RCU extended quiescent state on every CPUs by default. This is for testing purpose. Signed-off-by: Frederic Weisbecker Cc: Alessio Igor Bogani Cc: Andrew Morton Cc: Avi Kivity Cc: Chris Metcalf Cc: Christoph Lameter Cc: Geoff Levand Cc: Gilad Ben Yossef Cc: Hakan Akkan Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Josh Triplett Cc: Kevin Hilman Cc: Max Krasnyansky Cc: Peter Zijlstra Cc: Stephen Hemminger Cc: Steven Rostedt Cc: Sven-Thorsten Dietrich Cc: Thomas Gleixner Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- init/Kconfig | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'init/Kconfig') diff --git a/init/Kconfig b/init/Kconfig index f6a1830165ce..c26b8a1d2b57 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -451,6 +451,14 @@ config RCU_USER_QS excluded from the global RCU state machine and thus doesn't to keep the timer tick on for RCU. +config RCU_USER_QS_FORCE + bool "Force userspace extended QS by default" + depends on RCU_USER_QS + help + Set the hooks in user/kernel boundaries by default in order to + test this feature that treats userspace as an extended quiescent + state until we have a real user like a full adaptive nohz option. + config RCU_FANOUT int "Tree-based hierarchical RCU fanout value" range 2 64 if 64BIT -- cgit v1.2.3