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, 63 insertions, 0 deletions

diff --git a/tools/perf/tests/mem.c b/tools/perf/tests/mem.c
new file mode 100644
index 000000000..cb3d749e1
--- /dev/null
+++ b/tools/perf/tests/mem.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "util/map_symbol.h"
+#include "util/mem-events.h"
+#include "util/mem-info.h"
+#include "util/symbol.h"
+#include "linux/perf_event.h"
+#include "util/debug.h"
+#include "tests.h"
+#include <string.h>
+
+static int check(union perf_mem_data_src data_src,
+		  const char *string)
+{
+	char out[100];
+	char failure[100];
+	struct mem_info *mi = mem_info__new();
+	int n;
+
+	TEST_ASSERT_VAL("Memory allocation failed", mi);
+	*mem_info__data_src(mi) = data_src;
+	n = perf_mem__snp_scnprintf(out, sizeof out, mi);
+	n += perf_mem__lvl_scnprintf(out + n, sizeof out - n, mi);
+	mem_info__put(mi);
+	scnprintf(failure, sizeof failure, "unexpected %s", out);
+	TEST_ASSERT_VAL(failure, !strcmp(string, out));
+	return 0;
+}
+
+static int test__mem(struct test_suite *text __maybe_unused, int subtest __maybe_unused)
+{
+	int ret = 0;
+	union perf_mem_data_src src;
+
+	memset(&src, 0, sizeof(src));
+
+	src.mem_lvl = PERF_MEM_LVL_HIT;
+	src.mem_lvl_num = 4;
+
+	ret |= check(src, "N/AL4 hit");
+
+	src.mem_remote = 1;
+
+	ret |= check(src, "N/ARemote L4 hit");
+
+	src.mem_lvl = PERF_MEM_LVL_MISS;
+	src.mem_lvl_num = PERF_MEM_LVLNUM_PMEM;
+	src.mem_remote = 0;
+
+	ret |= check(src, "N/APMEM miss");
+
+	src.mem_remote = 1;
+
+	ret |= check(src, "N/ARemote PMEM miss");
+
+	src.mem_snoopx = PERF_MEM_SNOOPX_FWD;
+	src.mem_lvl_num = PERF_MEM_LVLNUM_RAM;
+
+	ret |= check(src , "FwdRemote RAM miss");
+
+	return ret;
+}
+
+DEFINE_SUITE("Test data source output", mem);