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authorLinus Torvalds <torvalds@linux-foundation.org>2022-05-23 21:46:51 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-05-23 21:46:51 +0300
commit1e57930e9f4083ad5854ab6eadffe790a8167fb4 (patch)
tree2056cde00f9578dcf76d9fe3ec89b5cdcd9d2bae /include/linux/sched.h
parentb2f02e9cdaade3ce565e6973ac313d2f814447f2 (diff)
parentce13389053a347aa9f8ffbfda2238352536e15c9 (diff)
downloadlinux-1e57930e9f4083ad5854ab6eadffe790a8167fb4.tar.xz
Merge tag 'rcu.2022.05.19a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU update from Paul McKenney: - Documentation updates - Miscellaneous fixes - Callback-offloading updates, mainly simplifications - RCU-tasks updates, including some -rt fixups, handling of systems with sparse CPU numbering, and a fix for a boot-time race-condition failure - Put SRCU on a memory diet in order to reduce the size of the srcu_struct structure - Torture-test updates fixing some bugs in tests and closing some testing holes - Torture-test updates for the RCU tasks flavors, most notably ensuring that building rcutorture and friends does not change the RCU-tasks-related Kconfig options - Torture-test scripting updates - Expedited grace-period updates, most notably providing milliseconds-scale (not all that) soft real-time response from synchronize_rcu_expedited(). This is also the first time in almost 30 years of RCU that someone other than me has pushed for a reduction in the RCU CPU stall-warning timeout, in this case by more than three orders of magnitude from 21 seconds to 20 milliseconds. This tighter timeout applies only to expedited grace periods * tag 'rcu.2022.05.19a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (80 commits) rcu: Move expedited grace period (GP) work to RT kthread_worker rcu: Introduce CONFIG_RCU_EXP_CPU_STALL_TIMEOUT srcu: Drop needless initialization of sdp in srcu_gp_start() srcu: Prevent expedited GPs and blocking readers from consuming CPU srcu: Add contention check to call_srcu() srcu_data ->lock acquisition srcu: Automatically determine size-transition strategy at boot rcutorture: Make torture.sh allow for --kasan rcutorture: Make torture.sh refscale and rcuscale specify Tasks Trace RCU rcutorture: Make kvm.sh allow more memory for --kasan runs torture: Save "make allmodconfig" .config file scftorture: Remove extraneous "scf" from per_version_boot_params rcutorture: Adjust scenarios' Kconfig options for CONFIG_PREEMPT_DYNAMIC torture: Enable CSD-lock stall reports for scftorture torture: Skip vmlinux check for kvm-again.sh runs scftorture: Adjust for TASKS_RCU Kconfig option being selected rcuscale: Allow rcuscale without RCU Tasks Rude/Trace rcuscale: Allow rcuscale without RCU Tasks refscale: Allow refscale without RCU Tasks Rude/Trace refscale: Allow refscale without RCU Tasks rcutorture: Allow specifying per-scenario stat_interval ...
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r--include/linux/sched.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a8911b1f35aa..b3278f8184d5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2118,6 +2118,47 @@ static inline void cond_resched_rcu(void)
#endif
}
+#ifdef CONFIG_PREEMPT_DYNAMIC
+
+extern bool preempt_model_none(void);
+extern bool preempt_model_voluntary(void);
+extern bool preempt_model_full(void);
+
+#else
+
+static inline bool preempt_model_none(void)
+{
+ return IS_ENABLED(CONFIG_PREEMPT_NONE);
+}
+static inline bool preempt_model_voluntary(void)
+{
+ return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
+}
+static inline bool preempt_model_full(void)
+{
+ return IS_ENABLED(CONFIG_PREEMPT);
+}
+
+#endif
+
+static inline bool preempt_model_rt(void)
+{
+ return IS_ENABLED(CONFIG_PREEMPT_RT);
+}
+
+/*
+ * Does the preemption model allow non-cooperative preemption?
+ *
+ * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
+ * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
+ * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
+ * PREEMPT_NONE model.
+ */
+static inline bool preempt_model_preemptible(void)
+{
+ return preempt_model_full() || preempt_model_rt();
+}
+
/*
* Does a critical section need to be broken due to another
* task waiting?: (technically does not depend on CONFIG_PREEMPTION,