| Kconfig (ae91aa0adb14dc33114d566feca2f7cb7a96b8b7) | Kconfig (44c65ff2e3b0b48250a970183ab53b0602c25764) |
|---|---|
| 1config ARCH 2 string 3 option env="ARCH" 4 5config KERNELVERSION 6 string 7 option env="KERNELVERSION" 8 --- 695 unchanged lines hidden (view full) --- 704 "s" for RCU-sched. Nothing prevents this kthread from running 705 on the specified CPUs, but (1) the kthreads may be preempted 706 between each callback, and (2) affinity or cgroups can be used 707 to force the kthreads to run on whatever set of CPUs is desired. 708 709 Say Y here if you want to help to debug reduced OS jitter. 710 Say N here if you are unsure. 711 | 1config ARCH 2 string 3 option env="ARCH" 4 5config KERNELVERSION 6 string 7 option env="KERNELVERSION" 8 --- 695 unchanged lines hidden (view full) --- 704 "s" for RCU-sched. Nothing prevents this kthread from running 705 on the specified CPUs, but (1) the kthreads may be preempted 706 between each callback, and (2) affinity or cgroups can be used 707 to force the kthreads to run on whatever set of CPUs is desired. 708 709 Say Y here if you want to help to debug reduced OS jitter. 710 Say N here if you are unsure. 711 |
| 712choice 713 prompt "Build-forced no-CBs CPUs" 714 default RCU_NOCB_CPU_NONE 715 depends on RCU_NOCB_CPU 716 help 717 This option allows no-CBs CPUs (whose RCU callbacks are invoked 718 from kthreads rather than from softirq context) to be specified 719 at build time. Additional no-CBs CPUs may be specified by 720 the rcu_nocbs= boot parameter. 721 722config RCU_NOCB_CPU_NONE 723 bool "No build_forced no-CBs CPUs" 724 help 725 This option does not force any of the CPUs to be no-CBs CPUs. 726 Only CPUs designated by the rcu_nocbs= boot parameter will be 727 no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU 728 kthreads whose names begin with "rcuo". All other CPUs will 729 invoke their own RCU callbacks in softirq context. 730 731 Select this option if you want to choose no-CBs CPUs at 732 boot time, for example, to allow testing of different no-CBs 733 configurations without having to rebuild the kernel each time. 734 735config RCU_NOCB_CPU_ZERO 736 bool "CPU 0 is a build_forced no-CBs CPU" 737 help 738 This option forces CPU 0 to be a no-CBs CPU, so that its RCU 739 callbacks are invoked by a per-CPU kthread whose name begins 740 with "rcuo". Additional CPUs may be designated as no-CBs 741 CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs. 742 All other CPUs will invoke their own RCU callbacks in softirq 743 context. 744 745 Select this if CPU 0 needs to be a no-CBs CPU for real-time 746 or energy-efficiency reasons, but the real reason it exists 747 is to ensure that randconfig testing covers mixed systems. 748 749config RCU_NOCB_CPU_ALL 750 bool "All CPUs are build_forced no-CBs CPUs" 751 help 752 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs= 753 boot parameter will be ignored. All CPUs' RCU callbacks will 754 be executed in the context of per-CPU rcuo kthreads created for 755 this purpose. Assuming that the kthreads whose names start with 756 "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter 757 on the remaining CPUs, but might decrease memory locality during 758 RCU-callback invocation, thus potentially degrading throughput. 759 760 Select this if all CPUs need to be no-CBs CPUs for real-time 761 or energy-efficiency reasons. 762 763endchoice 764 | |
| 765endmenu # "RCU Subsystem" 766 767config BUILD_BIN2C 768 bool 769 default n 770 771config IKCONFIG 772 tristate "Kernel .config support" --- 1397 unchanged lines hidden --- | 712endmenu # "RCU Subsystem" 713 714config BUILD_BIN2C 715 bool 716 default n 717 718config IKCONFIG 719 tristate "Kernel .config support" --- 1397 unchanged lines hidden --- |