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| author | Michal Hocko <mhocko@kernel.org> | 2021-01-18 15:12:19 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-02-17 14:12:24 +0100 |
| commit | 6ef869e0647439af0fc28dde162d33320d4e1dd7 (patch) | |
| tree | d9f08abf364f601b9b2ff6225fb4118b9ff739d4 /arch | |
| parent | 29fd01944b7273bb630c649a2104b7f9e4ef3fa6 (diff) | |
| download | linux-6ef869e0647439af0fc28dde162d33320d4e1dd7.tar.bz2 | |
preempt: Introduce CONFIG_PREEMPT_DYNAMIC
Preemption mode selection is currently hardcoded on Kconfig choices.
Introduce a dedicated option to tune preemption flavour at boot time,
This will be only available on architectures efficiently supporting
static calls in order not to tempt with the feature against additional
overhead that might be prohibitive or undesirable.
CONFIG_PREEMPT_DYNAMIC is automatically selected by CONFIG_PREEMPT if
the architecture provides the necessary support (CONFIG_STATIC_CALL_INLINE,
CONFIG_GENERIC_ENTRY, and provide with __preempt_schedule_function() /
__preempt_schedule_notrace_function()).
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
[peterz: relax requirement to HAVE_STATIC_CALL]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210118141223.123667-5-frederic@kernel.org
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 9 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 |
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 24862d15f3a3..124507907824 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1090,6 +1090,15 @@ config HAVE_STATIC_CALL_INLINE bool depends on HAVE_STATIC_CALL +config HAVE_PREEMPT_DYNAMIC + bool + depends on HAVE_STATIC_CALL + depends on GENERIC_ENTRY + help + Select this if the architecture support boot time preempt setting + on top of static calls. It is strongly advised to support inline + static call to avoid any overhead. + config ARCH_WANT_LD_ORPHAN_WARN bool help diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 21f851179ff0..d3338a87761f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -224,6 +224,7 @@ config X86 select HAVE_STACK_VALIDATION if X86_64 select HAVE_STATIC_CALL select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION + select HAVE_PREEMPT_DYNAMIC select HAVE_RSEQ select HAVE_SYSCALL_TRACEPOINTS select HAVE_UNSTABLE_SCHED_CLOCK |