This is a reworked version of what came out of the debate between Michal Hocko and Peter Zijlstra in order to tune the preemption mode from kernel parameters, see v2 in:
https://lore.kernel.org/lkml/20201009122926.29962-1-mho...@kernel.org/ I mostly fetched the raw diff from Peter's proof of concept using static calls + a few cherry picking here and there + some rework from my end. The result is still not complete, I still need to handle __cond_resched_lock() and other CONFIG_PREEMPT specifics. And also some others cleanup patches that were in Michal's series. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git preempt/dynamic HEAD: 764be94f20534c96e6f5a16922ad81c0a3bcd868 Thanks, Frederic --- Peter Zijlstra (Intel) (4): preempt/dynamic: Provide cond_resched() and might_resched() static calls preempt/dynamic: Provide preempt_schedule[_notrace]() static calls preempt/dynamic: Provide irqentry_exit_cond_resched() static call preempt/dynamic: Support dynamic preempt with preempt= boot option Peter Zijlstra (2): static_call/x86: Add __static_call_returnl0() static_call: Pull some static_call declarations to the type headers Michal Hocko (1): preempt: Introduce CONFIG_PREEMPT_DYNAMIC Documentation/admin-guide/kernel-parameters.txt | 7 ++ arch/Kconfig | 9 +++ arch/x86/Kconfig | 1 + arch/x86/include/asm/preempt.h | 34 ++++++--- arch/x86/include/asm/text-patching.h | 26 ++++++- arch/x86/kernel/alternative.c | 5 ++ arch/x86/kernel/static_call.c | 10 ++- include/linux/entry-common.h | 4 ++ include/linux/kernel.h | 22 +++++- include/linux/sched.h | 27 ++++++- include/linux/static_call.h | 21 ------ include/linux/static_call_types.h | 33 +++++++++ kernel/Kconfig.preempt | 19 +++++ kernel/entry/common.c | 10 ++- kernel/sched/core.c | 93 ++++++++++++++++++++++++- kernel/static_call.c | 10 +++ 16 files changed, 289 insertions(+), 42 deletions(-)
