Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 31 insertions, 0 deletions

diff --git a/tools/perf/util/evswitch.h b/tools/perf/util/evswitch.h
new file mode 100644
index 000000000..8ffdbe526
--- /dev/null
+++ b/tools/perf/util/evswitch.h
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2019, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
+#ifndef __PERF_EVSWITCH_H
+#define __PERF_EVSWITCH_H 1
+
+#include <stdbool.h>
+#include <stdio.h>
+
+struct evsel;
+struct evlist;
+
+struct evswitch {
+	struct evsel *on, *off;
+	const char   *on_name, *off_name;
+	bool	     discarding;
+	bool	     show_on_off_events;
+};
+
+int evswitch__init(struct evswitch *evswitch, struct evlist *evlist, FILE *fp);
+
+bool evswitch__discard(struct evswitch *evswitch, struct evsel *evsel);
+
+#define OPTS_EVSWITCH(evswitch)								  \
+	OPT_STRING(0, "switch-on", &(evswitch)->on_name,				  \
+		   "event", "Consider events after the occurrence of this event"),	  \
+	OPT_STRING(0, "switch-off", &(evswitch)->off_name,				  \
+		   "event", "Stop considering events after the occurrence of this event"), \
+	OPT_BOOLEAN(0, "show-on-off-events", &(evswitch)->show_on_off_events,		  \
+		    "Show the on/off switch events, used with --switch-on and --switch-off")
+
+#endif /* __PERF_EVSWITCH_H */