From 7d3b1ca751840f53036c303af2472b5dd020016a Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 2 Nov 2016 16:45:58 +0100 Subject: [PATCH 040/352] rcu: update: make RCU_EXPEDITE_BOOT default RCU_EXPEDITE_BOOT should speed up the boot process by enforcing synchronize_rcu_expedited() instead of synchronize_rcu() during the boot process. There should be no reason why one does not want this and there is no need worry about real time latency at this point. Therefore make it default. Signed-off-by: Sebastian Andrzej Siewior --- init/Kconfig | 13 ------------- kernel/rcu/update.c | 6 ++---- 2 files changed, 2 insertions(+), 17 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index d5a88fb..fd6d8c2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -790,19 +790,6 @@ config RCU_NOCB_CPU_ALL endchoice -config RCU_EXPEDITE_BOOT - bool - default n - help - This option enables expedited grace periods at boot time, - as if rcu_expedite_gp() had been invoked early in boot. - The corresponding rcu_unexpedite_gp() is invoked from - rcu_end_inkernel_boot(), which is intended to be invoked - at the end of the kernel-only boot sequence, just before - init is exec'ed. - - Accept the default if unsure. - endmenu # "RCU Subsystem" config BUILD_BIN2C diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 4f6db7e..019b470 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -132,8 +132,7 @@ bool rcu_gp_is_normal(void) } EXPORT_SYMBOL_GPL(rcu_gp_is_normal); -static atomic_t rcu_expedited_nesting = - ATOMIC_INIT(IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT) ? 1 : 0); +static atomic_t rcu_expedited_nesting = ATOMIC_INIT(1); /* * Should normal grace-period primitives be expedited? Intended for @@ -182,8 +181,7 @@ EXPORT_SYMBOL_GPL(rcu_unexpedite_gp); */ void rcu_end_inkernel_boot(void) { - if (IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT)) - rcu_unexpedite_gp(); + rcu_unexpedite_gp(); if (rcu_normal_after_boot) WRITE_ONCE(rcu_normal, 1); } -- 2.7.4