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, 71 insertions, 0 deletions

diff --git a/tools/perf/util/counts.c b/tools/perf/util/counts.c
new file mode 100644
index 000000000..11cd85b27
--- /dev/null
+++ b/tools/perf/util/counts.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include "evsel.h"
+#include "counts.h"
+#include <perf/threadmap.h>
+#include <linux/zalloc.h>
+
+struct perf_counts *perf_counts__new(int ncpus, int nthreads)
+{
+	struct perf_counts *counts = zalloc(sizeof(*counts));
+
+	if (counts) {
+		struct xyarray *values;
+
+		values = xyarray__new(ncpus, nthreads, sizeof(struct perf_counts_values));
+		if (!values) {
+			free(counts);
+			return NULL;
+		}
+
+		counts->values = values;
+
+		values = xyarray__new(ncpus, nthreads, sizeof(bool));
+		if (!values) {
+			xyarray__delete(counts->values);
+			free(counts);
+			return NULL;
+		}
+
+		counts->loaded = values;
+	}
+
+	return counts;
+}
+
+void perf_counts__delete(struct perf_counts *counts)
+{
+	if (counts) {
+		xyarray__delete(counts->loaded);
+		xyarray__delete(counts->values);
+		free(counts);
+	}
+}
+
+void perf_counts__reset(struct perf_counts *counts)
+{
+	xyarray__reset(counts->loaded);
+	xyarray__reset(counts->values);
+}
+
+void evsel__reset_counts(struct evsel *evsel)
+{
+	perf_counts__reset(evsel->counts);
+}
+
+int evsel__alloc_counts(struct evsel *evsel)
+{
+	struct perf_cpu_map *cpus = evsel__cpus(evsel);
+	int nthreads = perf_thread_map__nr(evsel->core.threads);
+
+	evsel->counts = perf_counts__new(perf_cpu_map__nr(cpus), nthreads);
+	return evsel->counts != NULL ? 0 : -ENOMEM;
+}
+
+void evsel__free_counts(struct evsel *evsel)
+{
+	perf_counts__delete(evsel->counts);
+	evsel->counts = NULL;
+}