Module: xenomai-3 Branch: next Commit: e3c0194faf039873dd2f671d350f11ed923862e2 URL: http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=e3c0194faf039873dd2f671d350f11ed923862e2
Author: Philippe Gerum <r...@xenomai.org> Date: Sat Nov 14 16:41:13 2015 +0100 cobalt/powerpc: drop support for unlocked context switch This feature never actually brought any measurable gain on powerpc platforms, compared to the complexity of its implementation in the pipeline. It was primarily aimed at reducing latency for interrupt handlers when costly cache and TLB flushes are required to switch context, at the expense of increasing the scheduling latency. It turned out to be counter-productive on common powerpc platforms, with efficient MMUs. This feature has been default off for a while now, and 4.1+ pipelines won't provide support for it anymore. Time to drop support from Xenomai too. --- kernel/cobalt/arch/powerpc/Kconfig | 20 +------------------- 1 file changed, 1 insertion(+), 19 deletions(-) diff --git a/kernel/cobalt/arch/powerpc/Kconfig b/kernel/cobalt/arch/powerpc/Kconfig index 40eae0b..1cabef3 100644 --- a/kernel/cobalt/arch/powerpc/Kconfig +++ b/kernel/cobalt/arch/powerpc/Kconfig @@ -5,29 +5,11 @@ config XENO_ARCH_MATH_EMU bool default y if MATH_EMU || MATH_EMULATION -config IPIPE_WANT_PREEMPTIBLE_SWITCH - bool - default y if XENO_ARCH_UNLOCKED_SWITCH - default n if !XENO_ARCH_UNLOCKED_SWITCH - config XENO_ARCH_FPU def_bool PPC_FPU config XENO_ARCH_SYS3264 def_bool n -menu "Machine/platform-specific options" - config XENO_ARCH_UNLOCKED_SWITCH - bool "Unlocked context switch" - depends on IPIPE_HAVE_PREEMPTIBLE_SWITCH - default y - help - - The Cobalt core may allow non-atomic execution of the - machine-dependent context switching code, so that other CPUs - and/or local interrupts may execute concurrently. - - This option reduces interrupt latency when costly cache and - TLB flushes are required to switch context. -endmenu + def_bool n _______________________________________________ Xenomai-git mailing list Xenomai-git@xenomai.org https://xenomai.org/mailman/listinfo/xenomai-git