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author | Michal Hocko <mhocko@kernel.org> | 2021-01-18 17:12:19 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2021-02-17 16:12:24 +0300 |
commit | 6ef869e0647439af0fc28dde162d33320d4e1dd7 (patch) | |
tree | d9f08abf364f601b9b2ff6225fb4118b9ff739d4 /Documentation | |
parent | 29fd01944b7273bb630c649a2104b7f9e4ef3fa6 (diff) | |
download | linux-6ef869e0647439af0fc28dde162d33320d4e1dd7.tar.xz |
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 'Documentation')
-rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a10b545c2070..78ab29400dd3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3916,6 +3916,13 @@ Format: {"off"} Disable Hardware Transactional Memory + preempt= [KNL] + Select preemption mode if you have CONFIG_PREEMPT_DYNAMIC + none - Limited to cond_resched() calls + voluntary - Limited to cond_resched() and might_sleep() calls + full - Any section that isn't explicitly preempt disabled + can be preempted anytime. + print-fatal-signals= [KNL] debug: print fatal signals |