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, 130 insertions, 0 deletions

diff --git a/tools/docs/gen-renames.py b/tools/docs/gen-renames.py
new file mode 100755
index 000000000..8cb3b2157
--- /dev/null
+++ b/tools/docs/gen-renames.py
@@ -0,0 +1,130 @@
+#! /usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright © 2025, Oracle and/or its affiliates.
+# Author: Vegard Nossum <vegard.nossum@oracle.com>
+
+"""Trawl repository history for renames of Documentation/**.rst files.
+
+Example:
+
+    tools/docs/gen-renames.py --rev HEAD > Documentation/.renames.txt
+"""
+
+import argparse
+import itertools
+import os
+import subprocess
+import sys
+
+parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+parser.add_argument('--rev', default='HEAD', help='generate renames up to this revision')
+
+args = parser.parse_args()
+
+def normalize(path):
+    prefix = 'Documentation/'
+    suffix = '.rst'
+
+    assert path.startswith(prefix)
+    assert path.endswith(suffix)
+
+    return path[len(prefix):-len(suffix)]
+
+class Name(object):
+    def __init__(self, name):
+        self.names = [name]
+
+    def rename(self, new_name):
+        self.names.append(new_name)
+
+names = {
+}
+
+for line in subprocess.check_output([
+    'git', 'log',
+    '--reverse',
+    '--oneline',
+    '--find-renames',
+    '--diff-filter=RD',
+    '--name-status',
+    '--format=commit %H',
+    # ~v4.8-ish is when Sphinx/.rst was added in the first place
+    f'v4.8..{args.rev}',
+    '--',
+    'Documentation/'
+], text=True).splitlines():
+    # rename
+    if line.startswith('R'):
+        _, old, new = line[1:].split('\t', 2)
+
+        if old.endswith('.rst') and new.endswith('.rst'):
+            old = normalize(old)
+            new = normalize(new)
+
+            name = names.get(old)
+            if name is None:
+                name = Name(old)
+            else:
+                del names[old]
+
+            name.rename(new)
+            names[new] = name
+
+        continue
+
+    # delete
+    if line.startswith('D'):
+        _, old = line.split('\t', 1)
+
+        if old.endswith('.rst'):
+            old = normalize(old)
+
+            # TODO: we could save added/modified files as well and propose
+            # them as alternatives
+            name = names.get(old)
+            if name is None:
+                pass
+            else:
+                del names[old]
+
+        continue
+
+#
+# Get the set of current files so we can sanity check that we aren't
+# redirecting any of those
+#
+
+current_files = set()
+for line in subprocess.check_output([
+    'git', 'ls-tree',
+    '-r',
+    '--name-only',
+    args.rev,
+    'Documentation/',
+], text=True).splitlines():
+    if line.endswith('.rst'):
+        current_files.add(normalize(line))
+
+#
+# Format/group/output result
+#
+
+result = []
+for _, v in names.items():
+    old_names = v.names[:-1]
+    new_name = v.names[-1]
+
+    for old_name in old_names:
+        if old_name == new_name:
+            # A file was renamed to its new name twice; don't redirect that
+            continue
+
+        if old_name in current_files:
+            # A file was recreated with a former name; don't redirect those
+            continue
+
+        result.append((old_name, new_name))
+
+for old_name, new_name in sorted(result):
+    print(f"{old_name} {new_name}")