Merge tag 'next.2025.05.17a' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

Pull RCU updates from Joel Fernandes: - Removed swake_up_one_online() workaround - Reverted an incorrect rcuog wake-up fix from offline softirq - Rust RCU Guard methods marked as inline - Updated MAINTAINERS with Joel’s and Zqiang's new email address - Replaced magic constant in rcu_seq_done_exact() with named constant - Added warning mechanism to validate rcu_seq_done_exact() - Switched SRCU polling API to use rcu_seq_done_exact() - Commented on redundant delta check in rcu_seq_done_exact() - Made ->gpwrap tests in rcutorture more frequent - Fixed reuse of ARM64 images in rcutorture - rcutorture improved to check Kconfig and reader conflict handling - Extracted logic from rcu_torture_one_read() for clarity - Updated LWN RCU API documentation links - Enabled --do-rt in torture.sh for CONFIG_PREEMPT_RT - Added tests for SRCU up/down reader primitives - Added comments and delays checks in rcutorture - Deprecated srcu_read_lock_lite() and srcu_read_unlock_lite() via checkpatch - Added --do-normal and --do-no-normal to torture.sh - Added RCU Rust binding tests to torture.sh - Reduced CPU overcommit and removed MAXSMP/CPUMASK_OFFSTACK in TREE01 - Replaced kmalloc() with kcalloc() in rcuscale - Refined listRCU example code for stale data elimination - Fixed hardirq count bug for x86 in cpu_stall_cputime - Added safety checks in rcu/nocb for offloaded rdp access - Other miscellaneous changes * tag 'next.2025.05.17a' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (27 commits) rcutorture: Fix issue with re-using old images on ARM64 rcutorture: Remove MAXSMP and CPUMASK_OFFSTACK from TREE01 rcutorture: Reduce TREE01 CPU overcommit torture: Check for "Call trace:" as well as "Call Trace:" rcutorture: Perform more frequent testing of ->gpwrap torture: Add testing of RCU's Rust bindings to torture.sh torture: Add --do-{,no-}normal to torture.sh checkpatch: Deprecate srcu_read_lock_lite() and srcu_read_unlock_lite() rcutorture: Comment invocations of tick_dep_set_task() rcu/nocb: Add Safe checks for access offloaded rdp rcuscale: using kcalloc() to relpace kmalloc() doc/RCU/listRCU: refine example code for eliminating stale data doc: Update LWN RCU API links in whatisRCU.rst Revert "rcu/nocb: Fix rcuog wake-up from offline softirq" rust: sync: rcu: Mark Guard methods as inline rcu/cpu_stall_cputime: fix the hardirq count for x86 architecture rcu: Remove swake_up_one_online() bandaid MAINTAINERS: Update Zqiang's email address rcutorture: Make torture.sh --do-rt use CONFIG_PREEMPT_RT srcu: Use rcu_seq_done_exact() for polling API ...
2025-05-26 14:20:50 -07:00
parent 66fd704da4 9c80e44337
commit 07046958f6
23 changed files with 403 additions and 124 deletions
--- a/Documentation/RCU/listRCU.rst
+++ b/Documentation/RCU/listRCU.rst
@@ -334,7 +334,7 @@ If the system-call audit module were to ever need to reject stale data, one way
 to accomplish this would be to add a ``deleted`` flag and a ``lock`` spinlock to the
 ``audit_entry`` structure, and modify audit_filter_task() as follows::

-	static enum audit_state audit_filter_task(struct task_struct *tsk)
+	static struct audit_entry *audit_filter_task(struct task_struct *tsk, char **key)
 	{
 		struct audit_entry *e;
 		enum audit_state   state;
@@ -346,16 +346,18 @@ to accomplish this would be to add a ``deleted`` flag and a ``lock`` spinlock to
 				if (e->deleted) {
 					spin_unlock(&e->lock);
 					rcu_read_unlock();
-					return AUDIT_BUILD_CONTEXT;
+					return NULL;
 				}
 				rcu_read_unlock();
 				if (state == AUDIT_STATE_RECORD)
 					*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
-				return state;
+				/* As long as e->lock is held, e is valid and
+				 * its value is not stale */
+				return e;
 			}
 		}
 		rcu_read_unlock();
-		return AUDIT_BUILD_CONTEXT;
+		return NULL;
 	}

 The ``audit_del_rule()`` function would need to set the ``deleted`` flag under the
--- a/Documentation/RCU/whatisRCU.rst
+++ b/Documentation/RCU/whatisRCU.rst
@@ -15,6 +15,9 @@ to start learning about RCU:
 |	2014 Big API Table           https://lwn.net/Articles/609973/
 | 6.	The RCU API, 2019 Edition    https://lwn.net/Articles/777036/
 |	2019 Big API Table           https://lwn.net/Articles/777165/
+| 7.	The RCU API, 2024 Edition    https://lwn.net/Articles/988638/
+|       2024 Background Information  https://lwn.net/Articles/988641/
+|	2024 Big API Table           https://lwn.net/Articles/988666/

 For those preferring video:

--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5672,6 +5672,31 @@
 			are zero, rcutorture acts as if is interpreted
 			they are all non-zero.

+	rcutorture.gpwrap_lag= [KNL]
+			Enable grace-period wrap lag testing. Setting
+			to false prevents the gpwrap lag test from
+			running. Default is true.
+
+	rcutorture.gpwrap_lag_gps= [KNL]
+			Set the value for grace-period wrap lag during
+			active lag testing periods. This controls how many
+			grace periods differences we tolerate between
+			rdp and rnp's gp_seq before setting overflow flag.
+			The default is always set to 8.
+
+	rcutorture.gpwrap_lag_cycle_mins= [KNL]
+			Set the total cycle duration for gpwrap lag
+			testing in minutes. This is the total time for
+			one complete cycle of active and inactive
+			testing periods. Default is 30 minutes.
+
+	rcutorture.gpwrap_lag_active_mins= [KNL]
+			Set the duration for which gpwrap lag is active
+			within each cycle, in minutes. During this time,
+			the grace-period wrap lag will be set to the
+			value specified by gpwrap_lag_gps. Default is
+			5 minutes.
+
 	rcutorture.irqreader= [KNL]
 			Run RCU readers from irq handlers, or, more
 			accurately, from a timer handler.  Not all RCU
--- a/8
+++ b/8
@@ -1682,7 +1682,7 @@ M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 M:	Arve Hjønnevåg <arve@android.com>
 M:	Todd Kjos <tkjos@android.com>
 M:	Martijn Coenen <maco@android.com>
-M:	Joel Fernandes <joel@joelfernandes.org>
+M:	Joel Fernandes <joelagnelf@nvidia.com>
 M:	Christian Brauner <christian@brauner.io>
 M:	Carlos Llamas <cmllamas@google.com>
 M:	Suren Baghdasaryan <surenb@google.com>
@@ -13746,7 +13746,7 @@ M:	Luc Maranget <luc.maranget@inria.fr>
 M:	"Paul E. McKenney" <paulmck@kernel.org>
 R:	Akira Yokosawa <akiyks@gmail.com>
 R:	Daniel Lustig <dlustig@nvidia.com>
-R:	Joel Fernandes <joel@joelfernandes.org>
+R:	Joel Fernandes <joelagnelf@nvidia.com>
 L:	linux-kernel@vger.kernel.org
 L:	linux-arch@vger.kernel.org
 L:	lkmm@lists.linux.dev
@@ -20514,14 +20514,14 @@ READ-COPY UPDATE (RCU)
 M:	"Paul E. McKenney" <paulmck@kernel.org>
 M:	Frederic Weisbecker <frederic@kernel.org> (kernel/rcu/tree_nocb.h)
 M:	Neeraj Upadhyay <neeraj.upadhyay@kernel.org> (kernel/rcu/tasks.h)
-M:	Joel Fernandes <joel@joelfernandes.org>
+M:	Joel Fernandes <joelagnelf@nvidia.com>
 M:	Josh Triplett <josh@joshtriplett.org>
 M:	Boqun Feng <boqun.feng@gmail.com>
 M:	Uladzislau Rezki <urezki@gmail.com>
 R:	Steven Rostedt <rostedt@goodmis.org>
 R:	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 R:	Lai Jiangshan <jiangshanlai@gmail.com>
-R:	Zqiang <qiang.zhang1211@gmail.com>
+R:	Zqiang <qiang.zhang@linux.dev>
 L:	rcu@vger.kernel.org
 S:	Supported
 W:	http://www.rdrop.com/users/paulmck/RCU/
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -57,6 +57,9 @@
 /* Low-order bit definition for polled grace-period APIs. */
 #define RCU_GET_STATE_COMPLETED	0x1

+/* A complete grace period count */
+#define RCU_SEQ_GP (RCU_SEQ_STATE_MASK + 1)
+
 extern int sysctl_sched_rt_runtime;

 /*
@@ -157,12 +160,21 @@ static inline bool rcu_seq_done(unsigned long *sp, unsigned long s)
 * Given a snapshot from rcu_seq_snap(), determine whether or not a
 * full update-side operation has occurred, but do not allow the
 * (ULONG_MAX / 2) safety-factor/guard-band.
+ *
+ * The token returned by get_state_synchronize_rcu_full() is based on
+ * rcu_state.gp_seq but it is tested in poll_state_synchronize_rcu_full()
+ * against the root rnp->gp_seq. Since rcu_seq_start() is first called
+ * on rcu_state.gp_seq and only later reflected on the root rnp->gp_seq,
+ * it is possible that rcu_seq_snap(rcu_state.gp_seq) returns 2 full grace
+ * periods ahead of the root rnp->gp_seq. To prevent false-positives with the
+ * full polling API that a wrap around instantly completed the GP, when nothing
+ * like that happened, adjust for the 2 GPs in the ULONG_CMP_LT().
 */
 static inline bool rcu_seq_done_exact(unsigned long *sp, unsigned long s)
 {
 	unsigned long cur_s = READ_ONCE(*sp);

-	return ULONG_CMP_GE(cur_s, s) || ULONG_CMP_LT(cur_s, s - (3 * RCU_SEQ_STATE_MASK + 1));
+	return ULONG_CMP_GE(cur_s, s) || ULONG_CMP_LT(cur_s, s - (2 * RCU_SEQ_GP));
 }

 /*
@@ -572,6 +584,8 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
 			       unsigned long c_old,
 			       unsigned long c);
 void rcu_gp_set_torture_wait(int duration);
+void rcu_set_gpwrap_lag(unsigned long lag);
+int rcu_get_gpwrap_count(int cpu);
 #else
 static inline void rcutorture_get_gp_data(int *flags, unsigned long *gp_seq)
 {
@@ -589,6 +603,8 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
 	do { } while (0)
 #endif
 static inline void rcu_gp_set_torture_wait(int duration) { }
+static inline void rcu_set_gpwrap_lag(unsigned long lag) { }
+static inline int rcu_get_gpwrap_count(int cpu) { return 0; }
 #endif
 unsigned long long rcutorture_gather_gp_seqs(void);
 void rcutorture_format_gp_seqs(unsigned long long seqs, char *cp, size_t len);
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -762,7 +762,7 @@ kfree_scale_thread(void *arg)
 		}

 		for (i = 0; i < kfree_alloc_num; i++) {
-			alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
+			alloc_ptr = kcalloc(kfree_mult, sizeof(struct kfree_obj), GFP_KERNEL);
 			if (!alloc_ptr)
 				return -ENOMEM;

--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -115,6 +115,10 @@ torture_param(int, nreaders, -1, "Number of RCU reader threads");
 torture_param(int, object_debug, 0, "Enable debug-object double call_rcu() testing");
 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
 torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (jiffies), 0=disable");
+torture_param(bool, gpwrap_lag, true, "Enable grace-period wrap lag testing");
+torture_param(int, gpwrap_lag_gps, 8, "Value to set for set_gpwrap_lag during an active testing period.");
+torture_param(int, gpwrap_lag_cycle_mins, 30, "Total cycle duration for gpwrap lag testing (in minutes)");
+torture_param(int, gpwrap_lag_active_mins, 5, "Duration for which gpwrap lag is active within each cycle (in minutes)");
 torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disable");
 torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)");
 torture_param(int, preempt_duration, 0, "Preemption duration (ms), zero to disable");
@@ -413,6 +417,8 @@ struct rcu_torture_ops {
 	bool (*reader_blocked)(void);
 	unsigned long long (*gather_gp_seqs)(void);
 	void (*format_gp_seqs)(unsigned long long seqs, char *cp, size_t len);
+	void (*set_gpwrap_lag)(unsigned long lag);
+	int (*get_gpwrap_count)(int cpu);
 	long cbflood_max;
 	int irq_capable;
 	int can_boost;
@@ -619,6 +625,8 @@ static struct rcu_torture_ops rcu_ops = {
 				  : NULL,
 	.gather_gp_seqs		= rcutorture_gather_gp_seqs,
 	.format_gp_seqs		= rcutorture_format_gp_seqs,
+	.set_gpwrap_lag		= rcu_set_gpwrap_lag,
+	.get_gpwrap_count	= rcu_get_gpwrap_count,
 	.irq_capable		= 1,
 	.can_boost		= IS_ENABLED(CONFIG_RCU_BOOST),
 	.extendables		= RCUTORTURE_MAX_EXTEND,
@@ -2164,53 +2172,70 @@ rcutorture_loop_extend(int *readstate, bool insoftirq, struct torture_random_sta
 	return &rtrsp[j];
 }

-/*
- * Do one read-side critical section, returning false if there was
- * no data to read.  Can be invoked both from process context and
- * from a timer handler.
- */
-static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
-{
-	bool checkpolling = !(torture_random(trsp) & 0xfff);
+struct rcu_torture_one_read_state {
+	bool checkpolling;
 	unsigned long cookie;
 	struct rcu_gp_oldstate cookie_full;
-	int i;
 	unsigned long started;
-	unsigned long completed;
-	int newstate;
 	struct rcu_torture *p;
-	int pipe_count;
-	bool preempted = false;
-	int readstate = 0;
-	struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS] = { { 0 } };
-	struct rt_read_seg *rtrsp = &rtseg[0];
-	struct rt_read_seg *rtrsp1;
+	int readstate;
+	struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS];
+	struct rt_read_seg *rtrsp;
 	unsigned long long ts;
+};

-	WARN_ON_ONCE(!rcu_is_watching());
-	newstate = rcutorture_extend_mask(readstate, trsp);
-	rcutorture_one_extend(&readstate, newstate, myid < 0, trsp, rtrsp++);
-	if (checkpolling) {
+static void init_rcu_torture_one_read_state(struct rcu_torture_one_read_state *rtorsp,
+					    struct torture_random_state *trsp)
+{
+	memset(rtorsp, 0, sizeof(*rtorsp));
+	rtorsp->checkpolling = !(torture_random(trsp) & 0xfff);
+	rtorsp->rtrsp = &rtorsp->rtseg[0];
+}
+
+/*
+ * Set up the first segment of a series of overlapping read-side
+ * critical sections.  The caller must have actually initiated the
+ * outermost read-side critical section.
+ */
+static bool rcu_torture_one_read_start(struct rcu_torture_one_read_state *rtorsp,
+				       struct torture_random_state *trsp, long myid)
+{
+	if (rtorsp->checkpolling) {
 		if (cur_ops->get_gp_state && cur_ops->poll_gp_state)
-			cookie = cur_ops->get_gp_state();
+			rtorsp->cookie = cur_ops->get_gp_state();
 		if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full)
-			cur_ops->get_gp_state_full(&cookie_full);
+			cur_ops->get_gp_state_full(&rtorsp->cookie_full);
 	}
-	started = cur_ops->get_gp_seq();
-	ts = rcu_trace_clock_local();
-	p = rcu_dereference_check(rcu_torture_current,
+	rtorsp->started = cur_ops->get_gp_seq();
+	rtorsp->ts = rcu_trace_clock_local();
+	rtorsp->p = rcu_dereference_check(rcu_torture_current,
 				  !cur_ops->readlock_held || cur_ops->readlock_held());
-	if (p == NULL) {
+	if (rtorsp->p == NULL) {
 		/* Wait for rcu_torture_writer to get underway */
-		rcutorture_one_extend(&readstate, 0, myid < 0, trsp, rtrsp);
+		rcutorture_one_extend(&rtorsp->readstate, 0, myid < 0, trsp, rtorsp->rtrsp);
 		return false;
 	}
-	if (p->rtort_mbtest == 0)
+	if (rtorsp->p->rtort_mbtest == 0)
 		atomic_inc(&n_rcu_torture_mberror);
-	rcu_torture_reader_do_mbchk(myid, p, trsp);
-	rtrsp = rcutorture_loop_extend(&readstate, myid < 0, trsp, rtrsp);
+	rcu_torture_reader_do_mbchk(myid, rtorsp->p, trsp);
+	return true;
+}
+
+/*
+ * Complete the last segment of a series of overlapping read-side
+ * critical sections and check for errors.
+ */
+static void rcu_torture_one_read_end(struct rcu_torture_one_read_state *rtorsp,
+				     struct torture_random_state *trsp, long myid)
+{
+	int i;
+	unsigned long completed;
+	int pipe_count;
+	bool preempted = false;
+	struct rt_read_seg *rtrsp1;
+
 	preempt_disable();
-	pipe_count = READ_ONCE(p->rtort_pipe_count);
+	pipe_count = READ_ONCE(rtorsp->p->rtort_pipe_count);
 	if (pipe_count > RCU_TORTURE_PIPE_LEN) {
 		// Should not happen in a correct RCU implementation,
 		// happens quite often for torture_type=busted.
@@ -2218,28 +2243,28 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
 	}
 	completed = cur_ops->get_gp_seq();
 	if (pipe_count > 1) {
-		do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
-					  ts, started, completed);
+		do_trace_rcu_torture_read(cur_ops->name, &rtorsp->p->rtort_rcu,
+					  rtorsp->ts, rtorsp->started, completed);
 		rcu_ftrace_dump(DUMP_ALL);
 	}
 	__this_cpu_inc(rcu_torture_count[pipe_count]);
-	completed = rcutorture_seq_diff(completed, started);
+	completed = rcutorture_seq_diff(completed, rtorsp->started);
 	if (completed > RCU_TORTURE_PIPE_LEN) {
 		/* Should not happen, but... */
 		completed = RCU_TORTURE_PIPE_LEN;
 	}
 	__this_cpu_inc(rcu_torture_batch[completed]);
 	preempt_enable();
-	if (checkpolling) {
+	if (rtorsp->checkpolling) {
 		if (cur_ops->get_gp_state && cur_ops->poll_gp_state)
-			WARN_ONCE(cur_ops->poll_gp_state(cookie),
+			WARN_ONCE(cur_ops->poll_gp_state(rtorsp->cookie),
 				  "%s: Cookie check 2 failed %s(%d) %lu->%lu\n",
 				  __func__,
 				  rcu_torture_writer_state_getname(),
 				  rcu_torture_writer_state,
-				  cookie, cur_ops->get_gp_state());
+				  rtorsp->cookie, cur_ops->get_gp_state());
 		if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full)
-			WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full),
+			WARN_ONCE(cur_ops->poll_gp_state_full(&rtorsp->cookie_full),
 				  "%s: Cookie check 6 failed %s(%d) online %*pbl\n",
 				  __func__,
 				  rcu_torture_writer_state_getname(),
@@ -2248,21 +2273,42 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
 	}
 	if (cur_ops->reader_blocked)
 		preempted = cur_ops->reader_blocked();
-	rcutorture_one_extend(&readstate, 0, myid < 0, trsp, rtrsp);
-	WARN_ON_ONCE(readstate);
+	rcutorture_one_extend(&rtorsp->readstate, 0, myid < 0, trsp, rtorsp->rtrsp);
+	WARN_ON_ONCE(rtorsp->readstate);
 	// This next splat is expected behavior if leakpointer, especially
 	// for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels.
-	WARN_ON_ONCE(leakpointer && READ_ONCE(p->rtort_pipe_count) > 1);
+	WARN_ON_ONCE(leakpointer && READ_ONCE(rtorsp->p->rtort_pipe_count) > 1);

 	/* If error or close call, record the sequence of reader protections. */
 	if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) {
 		i = 0;
-		for (rtrsp1 = &rtseg[0]; rtrsp1 < rtrsp; rtrsp1++)
+		for (rtrsp1 = &rtorsp->rtseg[0]; rtrsp1 < rtorsp->rtrsp; rtrsp1++)
 			err_segs[i++] = *rtrsp1;
 		rt_read_nsegs = i;
 		rt_read_preempted = preempted;
 	}
+}

+/*
+ * Do one read-side critical section, returning false if there was
+ * no data to read.  Can be invoked both from process context and
+ * from a timer handler.
+ */
+static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
+{
+	int newstate;
+	struct rcu_torture_one_read_state rtors;
+
+	WARN_ON_ONCE(!rcu_is_watching());
+	init_rcu_torture_one_read_state(&rtors, trsp);
+	newstate = rcutorture_extend_mask(rtors.readstate, trsp);
+	rcutorture_one_extend(&rtors.readstate, newstate, myid < 0, trsp, rtors.rtrsp++);
+	if (!rcu_torture_one_read_start(&rtors, trsp, myid)) {
+		rcutorture_one_extend(&rtors.readstate, 0, myid < 0, trsp, rtors.rtrsp);
+		return false;
+	}
+	rtors.rtrsp = rcutorture_loop_extend(&rtors.readstate, myid < 0, trsp, rtors.rtrsp);
+	rcu_torture_one_read_end(&rtors, trsp, myid);
 	return true;
 }

@@ -2307,7 +2353,7 @@ rcu_torture_reader(void *arg)
 	set_user_nice(current, MAX_NICE);
 	if (irqreader && cur_ops->irq_capable)
 		timer_setup_on_stack(&t, rcu_torture_timer, 0);
-	tick_dep_set_task(current, TICK_DEP_BIT_RCU);
+	tick_dep_set_task(current, TICK_DEP_BIT_RCU);  // CPU bound, so need tick.
 	do {
 		if (irqreader && cur_ops->irq_capable) {
 			if (!timer_pending(&t))
@@ -2394,6 +2440,7 @@ rcu_torture_stats_print(void)
 	int i;
 	long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
 	long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
+	long n_gpwraps = 0;
 	struct rcu_torture *rtcp;
 	static unsigned long rtcv_snap = ULONG_MAX;
 	static bool splatted;
@@ -2404,6 +2451,8 @@ rcu_torture_stats_print(void)
 			pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]);
 			batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]);
 		}
+		if (cur_ops->get_gpwrap_count)
+			n_gpwraps += cur_ops->get_gpwrap_count(cpu);
 	}
 	for (i = RCU_TORTURE_PIPE_LEN; i >= 0; i--) {
 		if (pipesummary[i] != 0)
@@ -2435,8 +2484,9 @@ rcu_torture_stats_print(void)
 		data_race(n_barrier_attempts),
 		data_race(n_rcu_torture_barrier_error));
 	pr_cont("read-exits: %ld ", data_race(n_read_exits)); // Statistic.
-	pr_cont("nocb-toggles: %ld:%ld\n",
+	pr_cont("nocb-toggles: %ld:%ld ",
 		atomic_long_read(&n_nocb_offload), atomic_long_read(&n_nocb_deoffload));
+	pr_cont("gpwraps: %ld\n", n_gpwraps);

 	pr_alert("%s%s ", torture_type, TORTURE_FLAG);
 	if (atomic_read(&n_rcu_torture_mberror) ||
@@ -3036,7 +3086,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
 	cver = READ_ONCE(rcu_torture_current_version);
 	gps = cur_ops->get_gp_seq();
 	rfp->rcu_launder_gp_seq_start = gps;
-	tick_dep_set_task(current, TICK_DEP_BIT_RCU);
+	tick_dep_set_task(current, TICK_DEP_BIT_RCU);  // CPU bound, so need tick.
 	while (time_before(jiffies, stopat) &&
 	       !shutdown_time_arrived() &&
 	       !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) {
@@ -3607,6 +3657,57 @@ static int rcu_torture_preempt(void *unused)

 static enum cpuhp_state rcutor_hp;

+static struct hrtimer gpwrap_lag_timer;
+static bool gpwrap_lag_active;
+
+/* Timer handler for toggling RCU grace-period sequence overflow test lag value */
+static enum hrtimer_restart rcu_gpwrap_lag_timer(struct hrtimer *timer)
+{
+	ktime_t next_delay;
+
+	if (gpwrap_lag_active) {
+		pr_alert("rcu-torture: Disabling gpwrap lag (value=0)\n");
+		cur_ops->set_gpwrap_lag(0);
+		gpwrap_lag_active = false;
+		next_delay = ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0);
+	} else {
+		pr_alert("rcu-torture: Enabling gpwrap lag (value=%d)\n", gpwrap_lag_gps);
+		cur_ops->set_gpwrap_lag(gpwrap_lag_gps);
+		gpwrap_lag_active = true;
+		next_delay = ktime_set(gpwrap_lag_active_mins * 60, 0);
+	}
+
+	if (torture_must_stop_irq())
+		return HRTIMER_NORESTART;
+
+	hrtimer_forward_now(timer, next_delay);
+	return HRTIMER_RESTART;
+}
+
+static int rcu_gpwrap_lag_init(void)
+{
+	if (!gpwrap_lag)
+		return 0;
+
+	if (gpwrap_lag_cycle_mins <= 0 || gpwrap_lag_active_mins <= 0) {
+		pr_alert("rcu-torture: lag timing parameters must be positive\n");
+		return -EINVAL;
+	}
+
+	hrtimer_setup(&gpwrap_lag_timer, rcu_gpwrap_lag_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	gpwrap_lag_active = false;
+	hrtimer_start(&gpwrap_lag_timer,
+		      ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0), HRTIMER_MODE_REL);
+
+	return 0;
+}
+
+static void rcu_gpwrap_lag_cleanup(void)
+{
+	hrtimer_cancel(&gpwrap_lag_timer);
+	cur_ops->set_gpwrap_lag(0);
+	gpwrap_lag_active = false;
+}
 static void
 rcu_torture_cleanup(void)
 {
@@ -3776,6 +3877,9 @@ rcu_torture_cleanup(void)
 	torture_cleanup_end();
 	if (cur_ops->gp_slow_unregister)
 		cur_ops->gp_slow_unregister(NULL);
+
+	if (gpwrap_lag && cur_ops->set_gpwrap_lag)
+		rcu_gpwrap_lag_cleanup();
 }

 static void rcu_torture_leak_cb(struct rcu_head *rhp)
@@ -4272,9 +4376,17 @@ rcu_torture_init(void)
 	}
 	if (object_debug)
 		rcu_test_debug_objects();
-	torture_init_end();
+
 	if (cur_ops->gp_slow_register && !WARN_ON_ONCE(!cur_ops->gp_slow_unregister))
 		cur_ops->gp_slow_register(&rcu_fwd_cb_nodelay);
+
+	if (gpwrap_lag && cur_ops->set_gpwrap_lag) {
+		firsterr = rcu_gpwrap_lag_init();
+		if (torture_init_error(firsterr))
+			goto unwind;
+	}
+
+	torture_init_end();
 	return 0;

 unwind:
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -1589,7 +1589,7 @@ EXPORT_SYMBOL_GPL(start_poll_synchronize_srcu);
 bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie)
 {
 	if (cookie != SRCU_GET_STATE_COMPLETED &&
-	    !rcu_seq_done(&ssp->srcu_sup->srcu_gp_seq, cookie))
+	    !rcu_seq_done_exact(&ssp->srcu_sup->srcu_gp_seq, cookie))
 		return false;
 	// Ensure that the end of the SRCU grace period happens before
 	// any subsequent code that the caller might execute.
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -80,6 +80,15 @@ static void rcu_sr_normal_gp_cleanup_work(struct work_struct *);
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, rcu_data) = {
 	.gpwrap = true,
 };
+
+int rcu_get_gpwrap_count(int cpu)
+{
+	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
+
+	return READ_ONCE(rdp->gpwrap_count);
+}
+EXPORT_SYMBOL_GPL(rcu_get_gpwrap_count);
+
 static struct rcu_state rcu_state = {
 	.level = { &rcu_state.node[0] },
 	.gp_state = RCU_GP_IDLE,
@@ -757,6 +766,25 @@ void rcu_request_urgent_qs_task(struct task_struct *t)
 	smp_store_release(per_cpu_ptr(&rcu_data.rcu_urgent_qs, cpu), true);
 }

+static unsigned long seq_gpwrap_lag = ULONG_MAX / 4;
+
+/**
+ * rcu_set_gpwrap_lag - Set RCU GP sequence overflow lag value.
+ * @lag_gps: Set overflow lag to this many grace period worth of counters
+ * which is used by rcutorture to quickly force a gpwrap situation.
+ * @lag_gps = 0 means we reset it back to the boot-time value.
+ */
+void rcu_set_gpwrap_lag(unsigned long lag_gps)
+{
+	unsigned long lag_seq_count;
+
+	lag_seq_count = (lag_gps == 0)
+			? ULONG_MAX / 4
+			: lag_gps << RCU_SEQ_CTR_SHIFT;
+	WRITE_ONCE(seq_gpwrap_lag, lag_seq_count);
+}
+EXPORT_SYMBOL_GPL(rcu_set_gpwrap_lag);
+
 /*
 * When trying to report a quiescent state on behalf of some other CPU,
 * it is our responsibility to check for and handle potential overflow
@@ -767,9 +795,11 @@ void rcu_request_urgent_qs_task(struct task_struct *t)
 static void rcu_gpnum_ovf(struct rcu_node *rnp, struct rcu_data *rdp)
 {
 	raw_lockdep_assert_held_rcu_node(rnp);
-	if (ULONG_CMP_LT(rcu_seq_current(&rdp->gp_seq) + ULONG_MAX / 4,
-			 rnp->gp_seq))
+	if (ULONG_CMP_LT(rcu_seq_current(&rdp->gp_seq) + seq_gpwrap_lag,
+			 rnp->gp_seq)) {
 		WRITE_ONCE(rdp->gpwrap, true);
+		WRITE_ONCE(rdp->gpwrap_count, READ_ONCE(rdp->gpwrap_count) + 1);
+	}
 	if (ULONG_CMP_LT(rdp->rcu_iw_gp_seq + ULONG_MAX / 4, rnp->gp_seq))
 		rdp->rcu_iw_gp_seq = rnp->gp_seq + ULONG_MAX / 4;
 }
@@ -801,6 +831,10 @@ static int rcu_watching_snap_save(struct rcu_data *rdp)
 	return 0;
 }

+#ifndef arch_irq_stat_cpu
+#define arch_irq_stat_cpu(cpu) 0
+#endif
+
 /*
 * Returns positive if the specified CPU has passed through a quiescent state
 * by virtue of being in or having passed through an dynticks idle state since
@@ -936,9 +970,9 @@ static int rcu_watching_snap_recheck(struct rcu_data *rdp)
 			rsrp->cputime_irq     = kcpustat_field(kcsp, CPUTIME_IRQ, cpu);
 			rsrp->cputime_softirq = kcpustat_field(kcsp, CPUTIME_SOFTIRQ, cpu);
 			rsrp->cputime_system  = kcpustat_field(kcsp, CPUTIME_SYSTEM, cpu);
-			rsrp->nr_hardirqs = kstat_cpu_irqs_sum(rdp->cpu);
-			rsrp->nr_softirqs = kstat_cpu_softirqs_sum(rdp->cpu);
-			rsrp->nr_csw = nr_context_switches_cpu(rdp->cpu);
+			rsrp->nr_hardirqs = kstat_cpu_irqs_sum(cpu) + arch_irq_stat_cpu(cpu);
+			rsrp->nr_softirqs = kstat_cpu_softirqs_sum(cpu);
+			rsrp->nr_csw = nr_context_switches_cpu(cpu);
 			rsrp->jiffies = jiffies;
 			rsrp->gp_seq = rdp->gp_seq;
 		}
@@ -1060,38 +1094,6 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
 	return needmore;
 }

-static void swake_up_one_online_ipi(void *arg)
-{
-	struct swait_queue_head *wqh = arg;
-
-	swake_up_one(wqh);
-}
-
-static void swake_up_one_online(struct swait_queue_head *wqh)
-{
-	int cpu = get_cpu();
-
-	/*
-	 * If called from rcutree_report_cpu_starting(), wake up
-	 * is dangerous that late in the CPU-down hotplug process. The
-	 * scheduler might queue an ignored hrtimer. Defer the wake up
-	 * to an online CPU instead.
-	 */
-	if (unlikely(cpu_is_offline(cpu))) {
-		int target;
-
-		target = cpumask_any_and(housekeeping_cpumask(HK_TYPE_RCU),
-					 cpu_online_mask);
-
-		smp_call_function_single(target, swake_up_one_online_ipi,
-					 wqh, 0);
-		put_cpu();
-	} else {
-		put_cpu();
-		swake_up_one(wqh);
-	}
-}
-
 /*
 * Awaken the grace-period kthread.  Don't do a self-awaken (unless in an
 * interrupt or softirq handler, in which case we just might immediately
@@ -1116,7 +1118,7 @@ static void rcu_gp_kthread_wake(void)
 		return;
 	WRITE_ONCE(rcu_state.gp_wake_time, jiffies);
 	WRITE_ONCE(rcu_state.gp_wake_seq, READ_ONCE(rcu_state.gp_seq));
-	swake_up_one_online(&rcu_state.gp_wq);
+	swake_up_one(&rcu_state.gp_wq);
 }

 /*
@@ -1798,6 +1800,7 @@ static noinline_for_stack bool rcu_gp_init(void)
 	struct rcu_data *rdp;
 	struct rcu_node *rnp = rcu_get_root();
 	bool start_new_poll;
+	unsigned long old_gp_seq;

 	WRITE_ONCE(rcu_state.gp_activity, jiffies);
 	raw_spin_lock_irq_rcu_node(rnp);
@@ -1825,7 +1828,12 @@ static noinline_for_stack bool rcu_gp_init(void)
 	 */
 	start_new_poll = rcu_sr_normal_gp_init();
 	/* Record GP times before starting GP, hence rcu_seq_start(). */
+	old_gp_seq = rcu_state.gp_seq;
 	rcu_seq_start(&rcu_state.gp_seq);
+	/* Ensure that rcu_seq_done_exact() guardband doesn't give false positives. */
+	WARN_ON_ONCE(IS_ENABLED(CONFIG_PROVE_RCU) &&
+		     rcu_seq_done_exact(&old_gp_seq, rcu_seq_snap(&rcu_state.gp_seq)));
+
 	ASSERT_EXCLUSIVE_WRITER(rcu_state.gp_seq);
 	trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq, TPS("start"));
 	rcu_poll_gp_seq_start(&rcu_state.gp_seq_polled_snap);
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -168,7 +168,7 @@ struct rcu_snap_record {
 	u64		cputime_irq;	/* Accumulated cputime of hard irqs */
 	u64		cputime_softirq;/* Accumulated cputime of soft irqs */
 	u64		cputime_system; /* Accumulated cputime of kernel tasks */
-	unsigned long	nr_hardirqs;	/* Accumulated number of hard irqs */
+	u64		nr_hardirqs;	/* Accumulated number of hard irqs */
 	unsigned int	nr_softirqs;	/* Accumulated number of soft irqs */
 	unsigned long long nr_csw;	/* Accumulated number of task switches */
 	unsigned long   jiffies;	/* Track jiffies value */
@@ -183,6 +183,7 @@ struct rcu_data {
 	bool		core_needs_qs;	/* Core waits for quiescent state. */
 	bool		beenonline;	/* CPU online at least once. */
 	bool		gpwrap;		/* Possible ->gp_seq wrap. */
+	unsigned int	gpwrap_count;	/* Count of GP sequence wrap. */
 	bool		cpu_started;	/* RCU watching this onlining CPU. */
 	struct rcu_node *mynode;	/* This CPU's leaf of hierarchy */
 	unsigned long grpmask;		/* Mask to apply to leaf qsmask. */
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -200,7 +200,7 @@ static void __rcu_report_exp_rnp(struct rcu_node *rnp,
 		if (rnp->parent == NULL) {
 			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			if (wake)
-				swake_up_one_online(&rcu_state.expedited_wq);
+				swake_up_one(&rcu_state.expedited_wq);

 			break;
 		}
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -216,7 +216,7 @@ static bool __wake_nocb_gp(struct rcu_data *rdp_gp,
 	raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags);
 	if (needwake) {
 		trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DoWake"));
-		swake_up_one_online(&rdp_gp->nocb_gp_wq);
+		swake_up_one(&rdp_gp->nocb_gp_wq);
 	}

 	return needwake;
@@ -554,19 +554,13 @@ static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone,
 			rcu_nocb_unlock(rdp);
 			wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE_LAZY,
 					   TPS("WakeLazy"));
-		} else if (!irqs_disabled_flags(flags) && cpu_online(rdp->cpu)) {
+		} else if (!irqs_disabled_flags(flags)) {
 			/* ... if queue was empty ... */
 			rcu_nocb_unlock(rdp);
 			wake_nocb_gp(rdp, false);
 			trace_rcu_nocb_wake(rcu_state.name, rdp->cpu,
 					    TPS("WakeEmpty"));
 		} else {
-			/*
-			 * Don't do the wake-up upfront on fragile paths.
-			 * Also offline CPUs can't call swake_up_one_online() from
-			 * (soft-)IRQs. Rely on the final deferred wake-up from
-			 * rcutree_report_cpu_dead()
-			 */
 			rcu_nocb_unlock(rdp);
 			wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE,
 					   TPS("WakeEmptyIsDeferred"));
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -29,7 +29,7 @@ static bool rcu_rdp_is_offloaded(struct rcu_data *rdp)
 		  (IS_ENABLED(CONFIG_HOTPLUG_CPU) && lockdep_is_cpus_held()) ||
 		  lockdep_is_held(&rdp->nocb_lock) ||
 		  lockdep_is_held(&rcu_state.nocb_mutex) ||
-		  (!(IS_ENABLED(CONFIG_PREEMPT_COUNT) && preemptible()) &&
+		  ((!(IS_ENABLED(CONFIG_PREEMPT_COUNT) && preemptible()) || softirq_count()) &&
 		   rdp == this_cpu_ptr(&rcu_data)) ||
 		  rcu_current_is_nocb_kthread(rdp)),
 		"Unsafe read of RCU_NOCB offloaded state"
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -435,8 +435,8 @@ static void print_cpu_stat_info(int cpu)
 	rsr.cputime_system  = kcpustat_field(kcsp, CPUTIME_SYSTEM, cpu);

 	pr_err("\t         hardirqs   softirqs   csw/system\n");
-	pr_err("\t number: %8ld %10d %12lld\n",
-		kstat_cpu_irqs_sum(cpu) - rsrp->nr_hardirqs,
+	pr_err("\t number: %8lld %10d %12lld\n",
+		kstat_cpu_irqs_sum(cpu) + arch_irq_stat_cpu(cpu) - rsrp->nr_hardirqs,
 		kstat_cpu_softirqs_sum(cpu) - rsrp->nr_softirqs,
 		nr_context_switches_cpu(cpu) - rsrp->nr_csw);
 	pr_err("\tcputime: %8lld %10lld %12lld   ==> %d(ms)\n",
--- a/rust/kernel/sync/rcu.rs
+++ b/rust/kernel/sync/rcu.rs
@@ -17,6 +17,7 @@ pub struct Guard(NotThreadSafe);

 impl Guard {
    /// Acquires the RCU read side lock and returns a guard.
+    #[inline]
    pub fn new() -> Self {
        // SAFETY: An FFI call with no additional requirements.
        unsafe { bindings::rcu_read_lock() };
@@ -25,16 +26,19 @@ impl Guard {
    }

    /// Explicitly releases the RCU read side lock.
+    #[inline]
    pub fn unlock(self) {}
 }

 impl Default for Guard {
+    #[inline]
    fn default() -> Self {
        Self::new()
    }
 }

 impl Drop for Guard {
+    #[inline]
    fn drop(&mut self) {
        // SAFETY: By the type invariants, the RCU read side is locked, so it is ok to unlock it.
        unsafe { bindings::rcu_read_unlock() };
@@ -42,6 +46,7 @@ impl Drop for Guard {
 }

 /// Acquires the RCU read side lock.
+#[inline]
 pub fn read_lock() -> Guard {
    Guard::new()
 }
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -839,6 +839,8 @@ our %deprecated_apis = (
 	"kunmap"				=> "kunmap_local",
 	"kmap_atomic"				=> "kmap_local_page",
 	"kunmap_atomic"				=> "kunmap_local",
+	"srcu_read_lock_lite"			=> "srcu_read_lock_fast",
+	"srcu_read_unlock_lite"			=> "srcu_read_unlock_fast",
 );

 #Create a search pattern for all these strings to speed up a loop below
--- a/tools/testing/selftests/rcutorture/bin/console-badness.sh
+++ b/tools/testing/selftests/rcutorture/bin/console-badness.sh
@@ -10,7 +10,7 @@
 #
 # Authors: Paul E. McKenney <paulmck@kernel.org>

-grep -E 'Badness|WARNING:|Warn|BUG|===========|BUG: KCSAN:|Call Trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state|rcu_.*kthread starved for|!!!' |
+grep -E 'Badness|WARNING:|Warn|BUG|===========|BUG: KCSAN:|Call Trace:|Call trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state|rcu_.*kthread starved for|!!!' |
 grep -v 'ODEBUG: ' |
 grep -v 'This means that this is a DEBUG kernel and it is' |
 grep -v 'Warning: unable to open an initial console' |
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -73,7 +73,7 @@ config_override_param "$config_dir/CFcommon.$(uname -m)" KcList \
 cp $T/KcList $resdir/ConfigFragment

 base_resdir=`echo $resdir | sed -e 's/\.[0-9]\+$//'`
-if test "$base_resdir" != "$resdir" && test -f $base_resdir/bzImage && test -f $base_resdir/vmlinux
+if test "$base_resdir" != "$resdir" && (test -f $base_resdir/bzImage || test -f $base_resdir/Image) && test -f $base_resdir/vmlinux
 then
 	# Rerunning previous test, so use that test's kernel.
 	QEMU="`identify_qemu $base_resdir/vmlinux`"
--- a/tools/testing/selftests/rcutorture/bin/parse-console.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-console.sh
@@ -148,7 +148,7 @@ then
 			summary="$summary  KCSAN: $n_kcsan"
 		fi
 	fi
-	n_calltrace=`grep -c 'Call Trace:' $file`
+	n_calltrace=`grep -Ec 'Call Trace:|Call trace:' $file`
 	if test "$n_calltrace" -ne 0
 	then
 		summary="$summary  Call Traces: $n_calltrace"
--- a/tools/testing/selftests/rcutorture/bin/srcu_lockdep.sh
+++ b/tools/testing/selftests/rcutorture/bin/srcu_lockdep.sh
@@ -39,8 +39,9 @@ do
 	shift
 done

-err=
 nerrs=0
+
+# Test lockdep's handling of deadlocks.
 for d in 0 1
 do
 	for t in 0 1 2
@@ -52,6 +53,12 @@ do
 			tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 5s --configs "SRCU-P" --kconfig "CONFIG_FORCE_NEED_SRCU_NMI_SAFE=y" --bootargs "rcutorture.test_srcu_lockdep=$val rcutorture.reader_flavor=0x2" --trust-make --datestamp "$ds/$val" > "$T/kvm.sh.out" 2>&1
 			ret=$?
 			mv "$T/kvm.sh.out" "$RCUTORTURE/res/$ds/$val"
+			if ! grep -q '^CONFIG_PROVE_LOCKING=y' .config
+			then
+				echo "rcu_torture_init_srcu_lockdep:Error: CONFIG_PROVE_LOCKING disabled in rcutorture SRCU-P scenario"
+				nerrs=$((nerrs+1))
+				err=1
+			fi
 			if test "$d" -ne 0 && test "$ret" -eq 0
 			then
 				err=1
@@ -71,6 +78,39 @@ do
 		done
 	done
 done
+
+# Test lockdep-enabled testing of mixed SRCU readers.
+for val in 0x1 0xf
+do
+	err=
+	tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 5s --configs "SRCU-P" --kconfig "CONFIG_FORCE_NEED_SRCU_NMI_SAFE=y" --bootargs "rcutorture.reader_flavor=$val" --trust-make --datestamp "$ds/$val" > "$T/kvm.sh.out" 2>&1
+	ret=$?
+	mv "$T/kvm.sh.out" "$RCUTORTURE/res/$ds/$val"
+	if ! grep -q '^CONFIG_PROVE_LOCKING=y' .config
+	then
+		echo "rcu_torture_init_srcu_lockdep:Error: CONFIG_PROVE_LOCKING disabled in rcutorture SRCU-P scenario"
+		nerrs=$((nerrs+1))
+		err=1
+	fi
+	if test "$val" -eq 0xf && test "$ret" -eq 0
+	then
+		err=1
+		echo -n Unexpected success for > "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+	fi
+	if test "$val" -eq 0x1 && test "$ret" -ne 0
+	then
+		err=1
+		echo -n Unexpected failure for > "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+	fi
+	if test -n "$err"
+	then
+		grep "rcu_torture_init_srcu_lockdep: test_srcu_lockdep = " "$RCUTORTURE/res/$ds/$val/SRCU-P/console.log" | sed -e 's/^.*rcu_torture_init_srcu_lockdep://' >> "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+		cat "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+		nerrs=$((nerrs+1))
+	fi
+done
+
+# Set up exit code.
 if test "$nerrs" -ne 0
 then
 	exit 1
--- a/tools/testing/selftests/rcutorture/bin/torture.sh
+++ b/tools/testing/selftests/rcutorture/bin/torture.sh
@@ -51,12 +51,15 @@ do_scftorture=yes
 do_rcuscale=yes
 do_refscale=yes
 do_kvfree=yes
+do_normal=yes
+explicit_normal=no
 do_kasan=yes
 do_kcsan=no
 do_clocksourcewd=yes
 do_rt=yes
 do_rcutasksflavors=yes
 do_srcu_lockdep=yes
+do_rcu_rust=no

 # doyesno - Helper function for yes/no arguments
 function doyesno () {
@@ -87,6 +90,7 @@ usage () {
 	echo "       --do-rcutorture / --do-no-rcutorture / --no-rcutorture"
 	echo "       --do-refscale / --do-no-refscale / --no-refscale"
 	echo "       --do-rt / --do-no-rt / --no-rt"
+	echo "       --do-rcu-rust / --do-no-rcu-rust / --no-rcu-rust"
 	echo "       --do-scftorture / --do-no-scftorture / --no-scftorture"
 	echo "       --do-srcu-lockdep / --do-no-srcu-lockdep / --no-srcu-lockdep"
 	echo "       --duration [ <minutes> | <hours>h | <days>d ]"
@@ -128,6 +132,8 @@ do
 		do_refscale=yes
 		do_rt=yes
 		do_kvfree=yes
+		do_normal=yes
+		explicit_normal=no
 		do_kasan=yes
 		do_kcsan=yes
 		do_clocksourcewd=yes
@@ -161,11 +167,17 @@ do
 		do_refscale=no
 		do_rt=no
 		do_kvfree=no
+		do_normal=no
+		explicit_normal=no
 		do_kasan=no
 		do_kcsan=no
 		do_clocksourcewd=no
 		do_srcu_lockdep=no
 		;;
+	--do-normal|--do-no-normal|--no-normal)
+		do_normal=`doyesno "$1" --do-normal`
+		explicit_normal=yes
+		;;
 	--do-rcuscale|--do-no-rcuscale|--no-rcuscale)
 		do_rcuscale=`doyesno "$1" --do-rcuscale`
 		;;
@@ -181,6 +193,9 @@ do
 	--do-rt|--do-no-rt|--no-rt)
 		do_rt=`doyesno "$1" --do-rt`
 		;;
+	--do-rcu-rust|--do-no-rcu-rust|--no-rcu-rust)
+		do_rcu_rust=`doyesno "$1" --do-rcu-rust`
+		;;
 	--do-scftorture|--do-no-scftorture|--no-scftorture)
 		do_scftorture=`doyesno "$1" --do-scftorture`
 		;;
@@ -242,6 +257,17 @@ trap 'rm -rf $T' 0 2
 echo " --- " $scriptname $args | tee -a $T/log
 echo " --- Results directory: " $ds | tee -a $T/log

+if test "$do_normal" = "no" && test "$do_kasan" = "no" && test "$do_kcsan" = "no"
+then
+	# Match old scripts so that "--do-none --do-rcutorture" does
+	# normal rcutorture testing, but no KASAN or KCSAN testing.
+	if test $explicit_normal = yes
+	then
+		echo " --- Everything disabled, so explicit --do-normal overridden" | tee -a $T/log
+	fi
+	do_normal=yes
+fi
+
 # Calculate rcutorture defaults and apportion time
 if test -z "$configs_rcutorture"
 then
@@ -332,9 +358,12 @@ function torture_set {
 	local kcsan_kmake_tag=
 	local flavor=$1
 	shift
-	curflavor=$flavor
-	torture_one "$@"
-	mv $T/last-resdir $T/last-resdir-nodebug || :
+	if test "$do_normal" = "yes"
+	then
+		curflavor=$flavor
+		torture_one "$@"
+		mv $T/last-resdir $T/last-resdir-nodebug || :
+	fi
 	if test "$do_kasan" = "yes"
 	then
 		curflavor=${flavor}-kasan
@@ -448,13 +477,57 @@ fi

 if test "$do_rt" = "yes"
 then
-	# With all post-boot grace periods forced to normal.
-	torture_bootargs="rcupdate.rcu_cpu_stall_suppress_at_boot=1 torture.disable_onoff_at_boot rcupdate.rcu_task_stall_timeout=30000 rcupdate.rcu_normal=1"
-	torture_set "rcurttorture" tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration "$duration_rcutorture" --configs "TREE03" --trust-make
+	# In both runs, disable testing of RCU priority boosting because
+	# -rt doesn't like its interaction with testing of callback
+	# flooding.
+
+	# With all post-boot grace periods forced to normal (default for PREEMPT_RT).
+	torture_bootargs="rcupdate.rcu_cpu_stall_suppress_at_boot=1 torture.disable_onoff_at_boot rcupdate.rcu_task_stall_timeout=30000 rcutorture.test_boost=0 rcutorture.preempt_duration=0"
+	torture_set "rcurttorture" tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration "$duration_rcutorture" --configs "TREE03" --kconfig "CONFIG_PREEMPT_RT=y CONFIG_EXPERT=y CONFIG_HZ_PERIODIC=n CONFIG_NO_HZ_IDLE=y CONFIG_RCU_NOCB_CPU=y" --trust-make

 	# With all post-boot grace periods forced to expedited.
-	torture_bootargs="rcupdate.rcu_cpu_stall_suppress_at_boot=1 torture.disable_onoff_at_boot rcupdate.rcu_task_stall_timeout=30000 rcupdate.rcu_expedited=1"
-	torture_set "rcurttorture-exp" tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration "$duration_rcutorture" --configs "TREE03" --trust-make
+	torture_bootargs="rcupdate.rcu_cpu_stall_suppress_at_boot=1 torture.disable_onoff_at_boot rcupdate.rcu_task_stall_timeout=30000 rcutorture.test_boost=0 rcupdate.rcu_normal_after_boot=0 rcupdate.rcu_expedited=1 rcutorture.preempt_duration=0"
+	torture_set "rcurttorture-exp" tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration "$duration_rcutorture" --configs "TREE03" --kconfig "CONFIG_PREEMPT_RT=y CONFIG_EXPERT=y CONFIG_HZ_PERIODIC=n CONFIG_NO_HZ_FULL=y CONFIG_RCU_NOCB_CPU=y" --trust-make
+fi
+
+if test "$do_rcu_rust" = "yes"
+then
+	echo " --- do-rcu-rust:" Start `date` | tee -a $T/log
+	rrdir="tools/testing/selftests/rcutorture/res/$ds/results-rcu-rust"
+	mkdir -p "$rrdir"
+	echo " --- make LLVM=1 rustavailable " | tee -a $rrdir/log > $rrdir/rustavailable.out
+	make LLVM=1 rustavailable > $T/rustavailable.out 2>&1
+	retcode=$?
+	echo $retcode > $rrdir/rustavailable.exitcode
+	cat $T/rustavailable.out | tee -a $rrdir/log >> $rrdir/rustavailable.out 2>&1
+	buildphase=rustavailable
+	if test "$retcode" -eq 0
+	then
+		echo " --- Running 'make mrproper' in order to run kunit." | tee -a $rrdir/log > $rrdir/mrproper.out
+		make mrproper > $rrdir/mrproper.out 2>&1
+		retcode=$?
+		echo $retcode > $rrdir/mrproper.exitcode
+		buildphase=mrproper
+	fi
+	if test "$retcode" -eq 0
+	then
+		echo " --- Running rust_doctests_kernel." | tee -a $rrdir/log > $rrdir/rust_doctests_kernel.out
+		./tools/testing/kunit/kunit.py run --make_options LLVM=1 --make_options CLIPPY=1 --arch arm64 --kconfig_add CONFIG_SMP=y --kconfig_add CONFIG_WERROR=y --kconfig_add CONFIG_RUST=y rust_doctests_kernel >> $rrdir/rust_doctests_kernel.out 2>&1
+		# @@@ Remove "--arch arm64" in order to test on native architecture?
+		# @@@ Analyze $rrdir/rust_doctests_kernel.out contents?
+		retcode=$?
+		echo $retcode > $rrdir/rust_doctests_kernel.exitcode
+		buildphase=rust_doctests_kernel
+	fi
+	if test "$retcode" -eq 0
+	then
+		echo "rcu-rust($retcode)" $rrdir >> $T/successes
+		echo Success >> $rrdir/log
+	else
+		echo "rcu-rust($retcode)" $rrdir >> $T/failures
+		echo " --- rcu-rust Test summary:" >> $rrdir/log
+		echo " --- Summary: Exit code $retcode from $buildphase, see $rrdir/$buildphase.out" >> $rrdir/log
+	fi
 fi

 if test "$do_srcu_lockdep" = "yes"
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01
@@ -8,8 +8,6 @@ CONFIG_NO_HZ_IDLE=y
 CONFIG_NO_HZ_FULL=n
 CONFIG_RCU_TRACE=y
 CONFIG_HOTPLUG_CPU=y
-CONFIG_MAXSMP=y
-CONFIG_CPUMASK_OFFSTACK=y
 CONFIG_RCU_NOCB_CPU=y
 CONFIG_DEBUG_LOCK_ALLOC=n
 CONFIG_RCU_BOOST=n
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
@@ -1,4 +1,4 @@
-maxcpus=8 nr_cpus=43
+maxcpus=8 nr_cpus=17
 rcutree.gp_preinit_delay=3
 rcutree.gp_init_delay=3
 rcutree.gp_cleanup_delay=3