From c072a388d59a1d48e36864d0e66f42d71745be1c Mon Sep 17 00:00:00 2001 From: Paul E. McKenney Date: Fri, 7 Jan 2011 02:33:47 -0800 Subject: rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status Because the adaptive synchronize_srcu_expedited() approach has worked very well in testing, remove the kernel parameter and replace it by a C-preprocessor macro. If someone finds problems with this approach, a more complex and aggressively adaptive approach might be required. Longer term, SRCU will be merged with the other RCU implementations, at which point synchronize_srcu_expedited() will be event driven, just as synchronize_sched_expedited() currently is. At that point, there will be no need for this adaptive approach. Reported-by: Linus Torvalds Signed-off-by: Paul E. McKenney --- init/Kconfig | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 526ec1c7456a..e11bc793a91d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -497,21 +497,6 @@ config RCU_BOOST_DELAY Accept the default if unsure. -config SRCU_SYNCHRONIZE_DELAY - int "Microseconds to delay before waiting for readers" - range 0 20 - default 10 - help - This option controls how long SRCU delays before entering its - loop waiting on SRCU readers. The purpose of this loop is - to avoid the unconditional context-switch penalty that would - otherwise be incurred if there was an active SRCU reader, - in a manner similar to adaptive locking schemes. This should - be set to be a bit longer than the common-case SRCU read-side - critical-section overhead. - - Accept the default if unsure. - endmenu # "RCU Subsystem" config IKCONFIG -- cgit v1.2.3