From 44c65ff2e3b0b48250a970183ab53b0602c25764 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 15 May 2017 16:26:34 -0700 Subject: rcu: Eliminate NOCBs CPU-state Kconfig options The CONFIG_RCU_NOCB_CPU_ALL, CONFIG_RCU_NOCB_CPU_NONE, and CONFIG_RCU_NOCB_CPU_ZERO Kconfig options are used only in testing and are redundant with the rcu_nocbs= boot parameter. This commit therefore removes these three Kconfig options and adjusts the rcutorture scripts to use the boot parameter instead. Signed-off-by: Paul E. McKenney --- init/Kconfig | 53 ----------------------------------------------------- 1 file changed, 53 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 3025383ab443..dc431c6109f2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -709,59 +709,6 @@ config RCU_NOCB_CPU Say Y here if you want to help to debug reduced OS jitter. Say N here if you are unsure. -choice - prompt "Build-forced no-CBs CPUs" - default RCU_NOCB_CPU_NONE - depends on RCU_NOCB_CPU - help - This option allows no-CBs CPUs (whose RCU callbacks are invoked - from kthreads rather than from softirq context) to be specified - at build time. Additional no-CBs CPUs may be specified by - the rcu_nocbs= boot parameter. - -config RCU_NOCB_CPU_NONE - bool "No build_forced no-CBs CPUs" - help - This option does not force any of the CPUs to be no-CBs CPUs. - Only CPUs designated by the rcu_nocbs= boot parameter will be - no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU - kthreads whose names begin with "rcuo". All other CPUs will - invoke their own RCU callbacks in softirq context. - - Select this option if you want to choose no-CBs CPUs at - boot time, for example, to allow testing of different no-CBs - configurations without having to rebuild the kernel each time. - -config RCU_NOCB_CPU_ZERO - bool "CPU 0 is a build_forced no-CBs CPU" - help - This option forces CPU 0 to be a no-CBs CPU, so that its RCU - callbacks are invoked by a per-CPU kthread whose name begins - with "rcuo". Additional CPUs may be designated as no-CBs - CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs. - All other CPUs will invoke their own RCU callbacks in softirq - context. - - Select this if CPU 0 needs to be a no-CBs CPU for real-time - or energy-efficiency reasons, but the real reason it exists - is to ensure that randconfig testing covers mixed systems. - -config RCU_NOCB_CPU_ALL - bool "All CPUs are build_forced no-CBs CPUs" - help - This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs= - boot parameter will be ignored. All CPUs' RCU callbacks will - be executed in the context of per-CPU rcuo kthreads created for - this purpose. Assuming that the kthreads whose names start with - "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter - on the remaining CPUs, but might decrease memory locality during - RCU-callback invocation, thus potentially degrading throughput. - - Select this if all CPUs need to be no-CBs CPUs for real-time - or energy-efficiency reasons. - -endchoice - endmenu # "RCU Subsystem" config BUILD_BIN2C -- cgit