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authorMichal Hocko <mhocko@kernel.org>2021-01-18 15:12:19 +0100
committerIngo Molnar <mingo@kernel.org>2021-02-17 14:12:24 +0100
commit6ef869e0647439af0fc28dde162d33320d4e1dd7 (patch)
treed9f08abf364f601b9b2ff6225fb4118b9ff739d4 /arch/Kconfig
parent29fd01944b7273bb630c649a2104b7f9e4ef3fa6 (diff)
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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/Kconfig')
-rw-r--r--arch/Kconfig9
1 files changed, 9 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