Merge branch 'core-rcu.2021.08.28a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:
 "RCU changes for this cycle were:

   - Documentation updates

   - Miscellaneous fixes

   - Offloaded-callbacks updates

   - Updates to the nolibc library

   - Tasks-RCU updates

   - In-kernel torture-test updates

   - Torture-test scripting, perhaps most notably the pinning of
     torture-test guest OSes so as to force differences in memory
     latency. For example, in a two-socket system, a four-CPU guest OS
     will have one pair of its CPUs pinned to threads in a single core
     on one socket and the other pair pinned to threads in a single core
     on the other socket. This approach proved able to force race
     conditions that earlier testing missed. Some of these race
     conditions are still being tracked down"

* 'core-rcu.2021.08.28a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (61 commits)
  torture: Replace deprecated CPU-hotplug functions.
  rcu: Replace deprecated CPU-hotplug functions
  rcu: Print human-readable message for schedule() in RCU reader
  rcu: Explain why rcu_all_qs() is a stub in preemptible TREE RCU
  rcu: Use per_cpu_ptr to get the pointer of per_cpu variable
  rcu: Remove useless "ret" update in rcu_gp_fqs_loop()
  rcu: Mark accesses in tree_stall.h
  rcu: Make rcu_gp_init() and rcu_gp_fqs_loop noinline to conserve stack
  rcu: Mark lockless ->qsmask read in rcu_check_boost_fail()
  srcutiny: Mark read-side data races
  rcu: Start timing stall repetitions after warning complete
  rcu: Do not disable GP stall detection in rcu_cpu_stall_reset()
  rcu/tree: Handle VM stoppage in stall detection
  rculist: Unify documentation about missing list_empty_rcu()
  rcu: Mark accesses to ->rcu_read_lock_nesting
  rcu: Weaken ->dynticks accesses and updates
  rcu: Remove special bit at the bottom of the ->dynticks counter
  rcu: Fix stall-warning deadlock due to non-release of rcu_node ->lock
  rcu: Fix to include first blocked task in stall warning
  torture: Make kvm-test-1-run-qemu.sh check for reboot loops
  ...

19 files changed, 382 insertions, 59 deletions

diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index 8b7a9830dd22..3430667b0d24 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -1031,7 +1031,7 @@ struct sys_stat_struct {
  *     scall32-o32.S in the kernel sources.
  *   - the system call is performed by calling "syscall"
  *   - syscall return comes in v0, and register a3 needs to be checked to know
- *     if an error occured, in which case errno is in v0.
+ *     if an error occurred, in which case errno is in v0.
  *   - the arguments are cast to long and assigned into the target registers
  *     which are then simply passed as registers to the asm code, so that we
  *     don't have to experience issues with register constraints.
@@ -2244,6 +2244,19 @@ unsigned int sleep(unsigned int seconds)
 }
 
 static __attribute__((unused))
+int msleep(unsigned int msecs)
+{
+	struct timeval my_timeval = { msecs / 1000, (msecs % 1000) * 1000 };
+
+	if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
+		return (my_timeval.tv_sec * 1000) +
+			(my_timeval.tv_usec / 1000) +
+			!!(my_timeval.tv_usec % 1000);
+	else
+		return 0;
+}
+
+static __attribute__((unused))
 int stat(const char *path, struct stat *buf)
 {
 	int ret = sys_stat(path, buf);
diff --git a/tools/testing/selftests/rcutorture/bin/jitter.sh b/tools/testing/selftests/rcutorture/bin/jitter.sh
index 15d937ba96ca..fd1ffaa5a135 100755
--- a/tools/testing/selftests/rcutorture/bin/jitter.sh
+++ b/tools/testing/selftests/rcutorture/bin/jitter.sh
@@ -68,16 +68,12 @@ do
 	cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN {
 		srand(n + me + systime());
 		ncpus = split(cpus, ca);
-		curcpu = ca[int(rand() * ncpus + 1)];
-		z = "";
-		for (i = 1; 4 * i <= curcpu; i++)
-			z = z "0";
-		print "0x" 2 ^ (curcpu % 4) z;
+		print ca[int(rand() * ncpus + 1)];
 	}' < /dev/null`
 	n=$(($n+1))
-	if ! taskset -p $cpumask $$ > /dev/null 2>&1
+	if ! taskset -c -p $cpumask $$ > /dev/null 2>&1
 	then
-		echo taskset failure: '"taskset -p ' $cpumask $$ '"'
+		echo taskset failure: '"taskset -c -p ' $cpumask $$ '"'
 		exit 1
 	fi
 
diff --git a/tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh b/tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh
index e5cc6b2f195e..1af5d6b86b39 100755
--- a/tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh
+++ b/tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh
@@ -14,7 +14,7 @@ if test -z "$TORTURE_KCONFIG_KCSAN_ARG"
 then
 	exit 0
 fi
-cat $1/*/console.log |
+find $1 -name console.log -exec cat {} \; |
 	grep "BUG: KCSAN: " |
 	sed -e 's/^\[[^]]*] //' |
 	sort |
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-again.sh b/tools/testing/selftests/rcutorture/bin/kvm-again.sh
index d8c8483c46f1..5a0023d183da 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-again.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-again.sh
@@ -142,7 +142,7 @@ then
 	echo "Cannot copy from $oldrun to $rundir."
 	usage
 fi
-rm -f "$rundir"/*/{console.log,console.log.diags,qemu_pid,qemu-retval,Warnings,kvm-test-1-run.sh.out,kvm-test-1-run-qemu.sh.out,vmlinux} "$rundir"/log
+rm -f "$rundir"/*/{console.log,console.log.diags,qemu_pid,qemu-pid,qemu-retval,Warnings,kvm-test-1-run.sh.out,kvm-test-1-run-qemu.sh.out,vmlinux} "$rundir"/log
 touch "$rundir/log"
 echo $scriptname $args | tee -a "$rundir/log"
 echo $oldrun > "$rundir/re-run"
@@ -179,6 +179,6 @@ if test -n "$dryrun"
 then
 	echo ---- Dryrun complete, directory: $rundir | tee -a "$rundir/log"
 else
-	( cd "$rundir"; sh $T/runbatches.sh )
+	( cd "$rundir"; sh $T/runbatches.sh ) | tee -a "$rundir/log"
 	kvm-end-run-stats.sh "$rundir" "$starttime"
 fi
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-assign-cpus.sh b/tools/testing/selftests/rcutorture/bin/kvm-assign-cpus.sh
new file mode 100755
index 000000000000..f99b2c146f83
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/kvm-assign-cpus.sh
@@ -0,0 +1,106 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Produce awk statements roughly depicting the system's CPU and cache
+# layout.  If the required information is not available, produce
+# error messages as awk comments.  Successful exit regardless.
+#
+# Usage: kvm-assign-cpus.sh /path/to/sysfs
+
+T=/tmp/kvm-assign-cpus.sh.$$
+trap 'rm -rf $T' 0 2
+mkdir $T
+
+sysfsdir=${1-/sys/devices/system/node}
+if ! cd "$sysfsdir" > $T/msg 2>&1
+then
+	sed -e 's/^/# /' < $T/msg
+	exit 0
+fi
+nodelist="`ls -d node*`"
+for i in node*
+do
+	if ! test -d $i/
+	then
+		echo "# Not a directory: $sysfsdir/node*"
+		exit 0
+	fi
+	for j in $i/cpu*/cache/index*
+	do
+		if ! test -d $j/
+		then
+			echo "# Not a directory: $sysfsdir/$j"
+			exit 0
+		else
+			break
+		fi
+	done
+	indexlist="`ls -d $i/cpu* | grep 'cpu[0-9][0-9]*' | head -1 | sed -e 's,^.*$,ls -d &/cache/index*,' | sh | sed -e 's,^.*/,,'`"
+	break
+done
+for i in node*/cpu*/cache/index*/shared_cpu_list
+do
+	if ! test -f $i
+	then
+		echo "# Not a file: $sysfsdir/$i"
+		exit 0
+	else
+		break
+	fi
+done
+firstshared=
+for i in $indexlist
+do
+	rm -f $T/cpulist
+	for n in node*
+	do
+		f="$n/cpu*/cache/$i/shared_cpu_list"
+		if ! cat $f > $T/msg 2>&1
+		then
+			sed -e 's/^/# /' < $T/msg
+			exit 0
+		fi
+		cat $f >> $T/cpulist
+	done
+	if grep -q '[-,]' $T/cpulist
+	then
+		if test -z "$firstshared"
+		then
+			firstshared="$i"
+		fi
+	fi
+done
+if test -z "$firstshared"
+then
+	splitindex="`echo $indexlist | sed -e 's/ .*$//'`"
+else
+	splitindex="$firstshared"
+fi
+nodenum=0
+for n in node*
+do
+	cat $n/cpu*/cache/$splitindex/shared_cpu_list | sort -u -k1n |
+	awk -v nodenum="$nodenum" '
+	BEGIN {
+		idx = 0;
+	}
+
+	{
+		nlists = split($0, cpulists, ",");
+		for (i = 1; i <= nlists; i++) {
+			listsize = split(cpulists[i], cpus, "-");
+			if (listsize == 1)
+				cpus[2] = cpus[1];
+			for (j = cpus[1]; j <= cpus[2]; j++) {
+				print "cpu[" nodenum "][" idx "] = " j ";";
+				idx++;
+			}
+		}
+	}
+
+	END {
+		print "nodecpus[" nodenum "] = " idx ";";
+	}'
+	nodenum=`expr $nodenum + 1`
+done
+echo "numnodes = $nodenum;"
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh b/tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh
new file mode 100755
index 000000000000..20c7c53c5795
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh
@@ -0,0 +1,88 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Create an awk script that takes as input numbers of CPUs and outputs
+# lists of CPUs, one per line in both cases.
+#
+# Usage: kvm-get-cpus-script.sh /path/to/cpu/arrays /path/to/put/script [ /path/to/state ]
+#
+# The CPU arrays are output by kvm-assign-cpus.sh, and are valid awk
+# statements initializing the variables describing the system's topology.
+#
+# The optional state is input by this script (if the file exists and is
+# non-empty), and can also be output by this script.
+
+cpuarrays="${1-/sys/devices/system/node}"
+scriptfile="${2}"
+statefile="${3}"
+
+if ! test -f "$cpuarrays"
+then
+	echo "File not found: $cpuarrays" 1>&2
+	exit 1
+fi
+scriptdir="`dirname "$scriptfile"`"
+if ! test -d "$scriptdir" || ! test -x "$scriptdir" || ! test -w "$scriptdir"
+then
+	echo "Directory not usable for script output: $scriptdir"
+	exit 1
+fi
+
+cat << '___EOF___' > "$scriptfile"
+BEGIN {
+___EOF___
+cat "$cpuarrays" >> "$scriptfile"
+if test -r "$statefile"
+then
+	cat "$statefile" >> "$scriptfile"
+fi
+cat << '___EOF___' >> "$scriptfile"
+}
+
+# Do we have the system architecture to guide CPU affinity?
+function gotcpus()
+{
+	return numnodes != "";
+}
+
+# Return a comma-separated list of the next n CPUs.
+function nextcpus(n,  i, s)
+{
+	for (i = 0; i < n; i++) {
+		if (nodecpus[curnode] == "")
+			curnode = 0;
+		if (cpu[curnode][curcpu[curnode]] == "")
+			curcpu[curnode] = 0;
+		if (s != "")
+			s = s ",";
+		s = s cpu[curnode][curcpu[curnode]];
+		curcpu[curnode]++;
+		curnode++
+	}
+	return s;
+}
+
+# Dump out the current node/CPU state so that a later invocation of this
+# script can continue where this one left off.  Of course, this only works
+# when a state file was specified and where there was valid sysfs state.
+# Returns 1 if the state was dumped, 0 otherwise.
+#
+# Dumping the state for one system configuration and loading it into
+# another isn't likely to do what you want, whatever that might be.
+function dumpcpustate(  i, fn)
+{
+___EOF___
+echo '	fn = "'"$statefile"'";' >> $scriptfile
+cat << '___EOF___' >> "$scriptfile"
+	if (fn != "" && gotcpus()) {
+		print "curnode = " curnode ";" > fn;
+		for (i = 0; i < numnodes; i++)
+			if (curcpu[i] != "")
+				print "curcpu[" i "] = " curcpu[i] ";" >> fn;
+		return 1;
+	}
+	if (fn != "")
+		print "# No CPU state to dump." > fn;
+	return 0;
+}
+___EOF___
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck-lock.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck-lock.sh
index f3a7a5e2b89d..db2c0e2c8e1d 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck-lock.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck-lock.sh
@@ -25,7 +25,7 @@ then
 	echo "$configfile -------"
 else
 	title="$configfile ------- $ncs acquisitions/releases"
-	dur=`sed -e 's/^.* locktorture.shutdown_secs=//' -e 's/ .*$//' < $i/qemu-cmd 2> /dev/null`
+	dur=`grep -v '^#' $i/qemu-cmd | sed -e 's/^.* locktorture.shutdown_secs=//' -e 's/ .*$//' 2> /dev/null`
 	if test -z "$dur"
 	then
 		:
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck-scf.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck-scf.sh
index 671bfee4fcef..3afa5c6eda4f 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck-scf.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck-scf.sh
@@ -25,7 +25,7 @@ if test -z "$nscfs"
 then
 	echo "$configfile ------- "
 else
-	dur="`sed -e 's/^.* scftorture.shutdown_secs=//' -e 's/ .*$//' < $i/qemu-cmd 2> /dev/null`"
+	dur="`grep -v '^#' $i/qemu-cmd | sed -e 's/^.* scftorture.shutdown_secs=//' -e 's/ .*$//' 2> /dev/null`"
 	if test -z "$dur"
 	then
 		rate=""
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
index e01b31b87044..0a5419982ab3 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
@@ -74,7 +74,10 @@ do
 	done
 	if test -f "$rd/kcsan.sum"
 	then
-		if grep -q CONFIG_KCSAN=y $T
+		if ! test -f $T
+		then
+			:
+		elif grep -q CONFIG_KCSAN=y $T
 		then
 			echo "Compiler or architecture does not support KCSAN!"
 			echo Did you forget to switch your compiler with '--kmake-arg CC=<cc-that-supports-kcsan>'?
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-remote-noreap.sh b/tools/testing/selftests/rcutorture/bin/kvm-remote-noreap.sh
new file mode 100755
index 000000000000..014ce68260d7
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/kvm-remote-noreap.sh
@@ -0,0 +1,30 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Periodically scan a directory tree to prevent files from being reaped
+# by systemd and friends on long runs.
+#
+# Usage: kvm-remote-noreap.sh pathname
+#
+# Copyright (C) 2021 Facebook, Inc.
+#
+# Authors: Paul E. McKenney <paulmck@kernel.org>
+
+pathname="$1"
+if test "$pathname" = ""
+then
+	echo Usage: kvm-remote-noreap.sh pathname
+	exit 1
+fi
+if ! test -d "$pathname"
+then
+	echo  Usage: kvm-remote-noreap.sh pathname
+	echo "       pathname must be a directory."
+	exit 2
+fi
+
+while test -d "$pathname"
+do
+	find "$pathname" -type f -exec touch -c {} \; > /dev/null 2>&1
+	sleep 30
+done
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
index 79e680e0e7bf..03126eb6ec5a 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
@@ -124,10 +124,12 @@ awk < "$rundir"/scenarios -v dest="$T/bin" -v rundir="$rundir" '
 	n = $1;
 	sub(/\./, "", n);
 	fn = dest "/kvm-remote-" n ".sh"
+	print "kvm-remote-noreap.sh " rundir " &" > fn;
 	scenarios = "";
 	for (i = 2; i <= NF; i++)
 		scenarios = scenarios " " $i;
-	print "kvm-test-1-run-batch.sh" scenarios > fn;
+	print "kvm-test-1-run-batch.sh" scenarios >> fn;
+	print "sync" >> fn;
 	print "rm " rundir "/remote.run" >> fn;
 }'
 chmod +x $T/bin/kvm-remote-*.sh
@@ -172,11 +174,20 @@ checkremotefile () {
 	do
 		ssh $1 "test -f \"$2\""
 		ret=$?
-		if test "$ret" -ne 255
+		if test "$ret" -eq 255
 		then
+			echo " ---" ssh failure to $1 checking for file $2, retry after $sleeptime seconds. `date`
+		elif test "$ret" -eq 0
+		then
+			return 0
+		elif test "$ret" -eq 1
+		then
+			echo " ---" File \"$2\" not found: ssh $1 test -f \"$2\"
+			return 1
+		else
+			echo " ---" Exit code $ret: ssh $1 test -f \"$2\", retry after $sleeptime seconds. `date`
 			return $ret
 		fi
-		echo " ---" ssh failure to $1 checking for file $2, retry after $sleeptime seconds. `date`
 		sleep $sleeptime
 	done
 }
@@ -242,7 +253,8 @@ do
 	do
 		sleep 30
 	done
-	( cd "$oldrun"; ssh $i "cd $rundir; tar -czf - kvm-remote-*.sh.out */console.log */kvm-test-1-run*.sh.out */qemu_pid */qemu-retval; rm -rf $T > /dev/null 2>&1" | tar -xzf - )
+	echo " ---" Collecting results from $i `date`
+	( cd "$oldrun"; ssh $i "cd $rundir; tar -czf - kvm-remote-*.sh.out */console.log */kvm-test-1-run*.sh.out */qemu[_-]pid */qemu-retval */qemu-affinity; rm -rf $T > /dev/null 2>&1" | tar -xzf - )
 done
 
 ( kvm-end-run-stats.sh "$oldrun" "$starttime"; echo $? > $T/exitcode ) | tee -a "$oldrun/remote-log"
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh
index 7ea0809e229e..1e29d656501b 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh
@@ -50,10 +50,34 @@ grep '^#' $1/qemu-cmd | sed -e 's/^# //' > $T/qemu-cmd-settings
 echo ---- System running test: `uname -a`
 echo ---- Starting kernels. `date` | tee -a log
 $TORTURE_JITTER_START
+kvm-assign-cpus.sh /sys/devices/system/node > $T/cpuarray.awk
 for i in "$@"
 do
 	echo ---- System running test: `uname -a` > $i/kvm-test-1-run-qemu.sh.out
 	echo > $i/kvm-test-1-run-qemu.sh.out
+	export TORTURE_AFFINITY=
+	kvm-get-cpus-script.sh $T/cpuarray.awk $T/cpubatches.awk $T/cpustate
+	cat << '	___EOF___' >> $T/cpubatches.awk
+	END {
+		affinitylist = "";
+		if (!gotcpus()) {
+			print "echo No CPU-affinity information, so no taskset command.";
+		} else if (cpu_count !~ /^[0-9][0-9]*$/) {
+			print "echo " scenario ": Bogus number of CPUs (old qemu-cmd?), so no taskset command.";
+		} else {
+			affinitylist = nextcpus(cpu_count);
+			if (!(affinitylist ~ /^[0-9,-][0-9,-]*$/))
+				print "echo " scenario ": Bogus CPU-affinity information, so no taskset command.";
+			else if (!dumpcpustate())
+				print "echo " scenario ": Could not dump state, so no taskset command.";
+			else
+				print "export TORTURE_AFFINITY=" affinitylist;
+		}
+	}
+	___EOF___
+	cpu_count="`grep '# TORTURE_CPU_COUNT=' $i/qemu-cmd | sed -e 's/^.*=//'`"
+	affinity_export="`awk -f $T/cpubatches.awk -v cpu_count="$cpu_count" -v scenario=$i < /dev/null`"
+	$affinity_export
 	kvm-test-1-run-qemu.sh $i >> $i/kvm-test-1-run-qemu.sh.out 2>&1 &
 done
 for i in $runfiles
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-qemu.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-qemu.sh
index 5b1aa2a4f3f6..44280582c594 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-qemu.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-qemu.sh
@@ -39,27 +39,34 @@ echo ' ---' `date`: Starting kernel, PID $$
 grep '^#' $resdir/qemu-cmd | sed -e 's/^# //' > $T/qemu-cmd-settings
 . $T/qemu-cmd-settings
 
-# Decorate qemu-cmd with redirection, backgrounding, and PID capture
-sed -e 's/$/ 2>\&1 \&/' < $resdir/qemu-cmd > $T/qemu-cmd
-echo 'echo $! > $resdir/qemu_pid' >> $T/qemu-cmd
+# Decorate qemu-cmd with affinity, redirection, backgrounding, and PID capture
+taskset_command=
+if test -n "$TORTURE_AFFINITY"
+then
+	taskset_command="taskset -c $TORTURE_AFFINITY "
+fi
+sed -e 's/^[^#].*$/'"$taskset_command"'& 2>\&1 \&/' < $resdir/qemu-cmd > $T/qemu-cmd
+echo 'qemu_pid=$!' >> $T/qemu-cmd
+echo 'echo $qemu_pid > $resdir/qemu-pid' >> $T/qemu-cmd
+echo 'taskset -c -p $qemu_pid > $resdir/qemu-affinity' >> $T/qemu-cmd
 
 # In case qemu refuses to run...
 echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log
 
 # Attempt to run qemu
 kstarttime=`gawk 'BEGIN { print systime() }' < /dev/null`
-( . $T/qemu-cmd; wait `cat  $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) &
+( . $T/qemu-cmd; wait `cat  $resdir/qemu-pid`; echo $? > $resdir/qemu-retval ) &
 commandcompleted=0
 if test -z "$TORTURE_KCONFIG_GDB_ARG"
 then
 	sleep 10 # Give qemu's pid a chance to reach the file
-	if test -s "$resdir/qemu_pid"
+	if test -s "$resdir/qemu-pid"
 	then
-		qemu_pid=`cat "$resdir/qemu_pid"`
-		echo Monitoring qemu job at pid $qemu_pid
+		qemu_pid=`cat "$resdir/qemu-pid"`
+		echo Monitoring qemu job at pid $qemu_pid `date`
 	else
 		qemu_pid=""
-		echo Monitoring qemu job at yet-as-unknown pid
+		echo Monitoring qemu job at yet-as-unknown pid `date`
 	fi
 fi
 if test -n "$TORTURE_KCONFIG_GDB_ARG"
@@ -82,9 +89,9 @@ then
 fi
 while :
 do
-	if test -z "$qemu_pid" -a -s "$resdir/qemu_pid"
+	if test -z "$qemu_pid" && test -s "$resdir/qemu-pid"
 	then
-		qemu_pid=`cat "$resdir/qemu_pid"`
+		qemu_pid=`cat "$resdir/qemu-pid"`
 	fi
 	kruntime=`gawk 'BEGIN { print systime() - '"$kstarttime"' }' < /dev/null`
 	if test -z "$qemu_pid" || kill -0 "$qemu_pid" > /dev/null 2>&1
@@ -115,22 +122,22 @@ do
 		break
 	fi
 done
-if test -z "$qemu_pid" -a -s "$resdir/qemu_pid"
+if test -z "$qemu_pid" && test -s "$resdir/qemu-pid"
 then
-	qemu_pid=`cat "$resdir/qemu_pid"`
+	qemu_pid=`cat "$resdir/qemu-pid"`
 fi
-if test $commandcompleted -eq 0 -a -n "$qemu_pid"
+if test $commandcompleted -eq 0 && test -n "$qemu_pid"
 then
 	if ! test -f "$resdir/../STOP.1"
 	then
-		echo Grace period for qemu job at pid $qemu_pid
+		echo Grace period for qemu job at pid $qemu_pid `date`
 	fi
 	oldline="`tail $resdir/console.log`"
 	while :
 	do
 		if test -f "$resdir/../STOP.1"
 		then
-			echo "PID $qemu_pid killed due to run STOP.1 request" >> $resdir/Warnings 2>&1
+			echo "PID $qemu_pid killed due to run STOP.1 request `date`" >> $resdir/Warnings 2>&1
 			kill -KILL $qemu_pid
 			break
 		fi
@@ -152,13 +159,17 @@ then
 		then
 			last_ts=0
 		fi
-		if test "$newline" != "$oldline" -a "$last_ts" -lt $((seconds + $TORTURE_SHUTDOWN_GRACE))
+		if test "$newline" != "$oldline" && test "$last_ts" -lt $((seconds + $TORTURE_SHUTDOWN_GRACE)) && test "$last_ts" -gt "$TORTURE_SHUTDOWN_GRACE"
 		then
 			must_continue=yes
+			if test $kruntime -ge $((seconds + $TORTURE_SHUTDOWN_GRACE))
+			then
+				echo Continuing at console.log time $last_ts \"`tail -n 1 $resdir/console.log`\" `date`
+			fi
 		fi
-		if test $must_continue = no -a $kruntime -ge $((seconds + $TORTURE_SHUTDOWN_GRACE))
+		if test $must_continue = no && test $kruntime -ge $((seconds + $TORTURE_SHUTDOWN_GRACE))
 		then
-			echo "!!! PID $qemu_pid hung at $kruntime vs. $seconds seconds" >> $resdir/Warnings 2>&1
+			echo "!!! PID $qemu_pid hung at $kruntime vs. $seconds seconds `date`" >> $resdir/Warnings 2>&1
 			kill -KILL $qemu_pid
 			break
 		fi
@@ -172,5 +183,3 @@ fi
 
 # Tell the script that this run is done.
 rm -f $resdir/build.run
-
-parse-console.sh $resdir/console.log $title
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
index 420ed5ce9d32..f4c8055dbf7a 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -205,6 +205,7 @@ echo "# TORTURE_KCONFIG_GDB_ARG=\"$TORTURE_KCONFIG_GDB_ARG\"" >> $resdir/qemu-cm
 echo "# TORTURE_JITTER_START=\"$TORTURE_JITTER_START\"" >> $resdir/qemu-cmd
 echo "# TORTURE_JITTER_STOP=\"$TORTURE_JITTER_STOP\"" >> $resdir/qemu-cmd
 echo "# TORTURE_TRUST_MAKE=\"$TORTURE_TRUST_MAKE\"; export TORTURE_TRUST_MAKE" >> $resdir/qemu-cmd
+echo "# TORTURE_CPU_COUNT=$cpu_count" >> $resdir/qemu-cmd
 
 if test -n "$TORTURE_BUILDONLY"
 then
@@ -214,3 +215,4 @@ then
 fi
 
 kvm-test-1-run-qemu.sh $resdir
+parse-console.sh $resdir/console.log $title
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index b4ac4ee33222..f442d84fb2a3 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -430,17 +430,10 @@ then
 	git diff HEAD >> $resdir/$ds/testid.txt
 fi
 ___EOF___
-awk < $T/cfgcpu.pack \
-	-v TORTURE_BUILDONLY="$TORTURE_BUILDONLY" \
-	-v CONFIGDIR="$CONFIGFRAG/" \
-	-v KVM="$KVM" \
-	-v ncpus=$cpus \
-	-v jitter="$jitter" \
-	-v rd=$resdir/$ds/ \
-	-v dur=$dur \
-	-v TORTURE_QEMU_ARG="$TORTURE_QEMU_ARG" \
-	-v TORTURE_BOOTARGS="$TORTURE_BOOTARGS" \
-'BEGIN {
+kvm-assign-cpus.sh /sys/devices/system/node > $T/cpuarray.awk
+kvm-get-cpus-script.sh $T/cpuarray.awk $T/dumpbatches.awk
+cat << '___EOF___' >> $T/dumpbatches.awk
+BEGIN {
 	i = 0;
 }
 
@@ -451,7 +444,7 @@ awk < $T/cfgcpu.pack \
 }
 
 # Dump out the scripting required to run one test batch.
-function dump(first, pastlast, batchnum)
+function dump(first, pastlast, batchnum,  affinitylist)
 {
 	print "echo ----Start batch " batchnum ": `date` | tee -a " rd "log";
 	print "needqemurun="
@@ -483,6 +476,14 @@ function dump(first, pastlast, batchnum)
 		print "echo ", cfr[jn], cpusr[jn] ovf ": Starting build. `date` | tee -a " rd "log";
 		print "mkdir " rd cfr[jn] " || :";
 		print "touch " builddir ".wait";
+		affinitylist = "";
+		if (gotcpus()) {
+			affinitylist = nextcpus(cpusr[jn]);
+		}
+		if (affinitylist ~ /^[0-9,-][0-9,-]*$/)
+			print "export TORTURE_AFFINITY=" affinitylist;
+		else
+			print "export TORTURE_AFFINITY=";
 		print "kvm-test-1-run.sh " CONFIGDIR cf[j], rd cfr[jn], dur " \"" TORTURE_QEMU_ARG "\" \"" TORTURE_BOOTARGS "\" > " rd cfr[jn]  "/kvm-test-1-run.sh.out 2>&1 &"
 		print "echo ", cfr[jn], cpusr[jn] ovf ": Waiting for build to complete. `date` | tee -a " rd "log";
 		print "while test -f " builddir ".wait"
@@ -560,7 +561,19 @@ END {
 	# Dump the last batch.
 	if (ncpus != 0)
 		dump(first, i, batchnum);
-}' >> $T/script
+}
+___EOF___
+awk < $T/cfgcpu.pack \
+	-v TORTURE_BUILDONLY="$TORTURE_BUILDONLY" \
+	-v CONFIGDIR="$CONFIGFRAG/" \
+	-v KVM="$KVM" \
+	-v ncpus=$cpus \
+	-v jitter="$jitter" \
+	-v rd=$resdir/$ds/ \
+	-v dur=$dur \
+	-v TORTURE_QEMU_ARG="$TORTURE_QEMU_ARG" \
+	-v TORTURE_BOOTARGS="$TORTURE_BOOTARGS" \
+	-f $T/dumpbatches.awk >> $T/script
 echo kvm-end-run-stats.sh "$resdir/$ds" "$starttime" >> $T/script
 
 # Extract the tests and their batches from the script.
diff --git a/tools/testing/selftests/rcutorture/bin/torture.sh b/tools/testing/selftests/rcutorture/bin/torture.sh
index 53ec7c046262..363f56081eff 100755
--- a/tools/testing/selftests/rcutorture/bin/torture.sh
+++ b/tools/testing/selftests/rcutorture/bin/torture.sh
@@ -53,6 +53,7 @@ do_refscale=yes
 do_kvfree=yes
 do_kasan=yes
 do_kcsan=no
+do_clocksourcewd=yes
 
 # doyesno - Helper function for yes/no arguments
 function doyesno () {
@@ -72,6 +73,7 @@ usage () {
 	echo "       --configs-scftorture \"config-file list w/ repeat factor (2*CFLIST)\""
 	echo "       --doall"
 	echo "       --doallmodconfig / --do-no-allmodconfig"
+	echo "       --do-clocksourcewd / --do-no-clocksourcewd"
 	echo "       --do-kasan / --do-no-kasan"
 	echo "       --do-kcsan / --do-no-kcsan"
 	echo "       --do-kvfree / --do-no-kvfree"
@@ -109,7 +111,7 @@ do
 		configs_scftorture="$configs_scftorture $2"
 		shift
 		;;
-	--doall)
+	--do-all|--doall)
 		do_allmodconfig=yes
 		do_rcutorture=yes
 		do_locktorture=yes
@@ -119,10 +121,14 @@ do
 		do_kvfree=yes
 		do_kasan=yes
 		do_kcsan=yes
+		do_clocksourcewd=yes
 		;;
 	--do-allmodconfig|--do-no-allmodconfig)
 		do_allmodconfig=`doyesno "$1" --do-allmodconfig`
 		;;
+	--do-clocksourcewd|--do-no-clocksourcewd)
+		do_clocksourcewd=`doyesno "$1" --do-clocksourcewd`
+		;;
 	--do-kasan|--do-no-kasan)
 		do_kasan=`doyesno "$1" --do-kasan`
 		;;
@@ -135,7 +141,7 @@ do
 	--do-locktorture|--do-no-locktorture)
 		do_locktorture=`doyesno "$1" --do-locktorture`
 		;;
-	--do-none)
+	--do-none|--donone)
 		do_allmodconfig=no
 		do_rcutorture=no
 		do_locktorture=no
@@ -145,6 +151,7 @@ do
 		do_kvfree=no
 		do_kasan=no
 		do_kcsan=no
+		do_clocksourcewd=no
 		;;
 	--do-rcuscale|--do-no-rcuscale)
 		do_rcuscale=`doyesno "$1" --do-rcuscale`
@@ -279,9 +286,9 @@ function torture_one {
 #	torture_bootargs="[ kernel boot arguments ]"
 #	torture_set flavor [ kvm.sh arguments ]
 #
-# Note that "flavor" is an arbitrary string.  Supply --torture if needed.
-# Note that quoting is problematic.  So on the command line, pass multiple
-# values with multiple kvm.sh argument instances.
+# Note that "flavor" is an arbitrary string that does not affect kvm.sh
+# in any way.  So also supply --torture if you need something other than
+# the default.
 function torture_set {
 	local cur_kcsan_kmake_args=
 	local kcsan_kmake_tag=
@@ -377,6 +384,22 @@ then
 	torture_set "rcuscale-kvfree" tools/testing/selftests/rcutorture/bin/kvm.sh --torture rcuscale --allcpus --duration 10 --kconfig "CONFIG_NR_CPUS=$HALF_ALLOTED_CPUS" --memory 1G --trust-make
 fi
 
+if test "$do_clocksourcewd" = "yes"
+then
+	torture_bootargs="rcupdate.rcu_cpu_stall_suppress_at_boot=1 torture.disable_onoff_at_boot rcupdate.rcu_task_stall_timeout=30000"
+	torture_set "clocksourcewd-1" tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 45s --configs TREE03 --kconfig "CONFIG_TEST_CLOCKSOURCE_WATCHDOG=y" --trust-make
+
+	torture_bootargs="rcupdate.rcu_cpu_stall_suppress_at_boot=1 torture.disable_onoff_at_boot rcupdate.rcu_task_stall_timeout=30000 clocksource.max_cswd_read_retries=1"
+	torture_set "clocksourcewd-2" tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 45s --configs TREE03 --kconfig "CONFIG_TEST_CLOCKSOURCE_WATCHDOG=y" --trust-make
+
+	# In case our work is already done...
+	if test "$do_rcutorture" != "yes"
+	then
+		torture_bootargs="rcupdate.rcu_cpu_stall_suppress_at_boot=1 torture.disable_onoff_at_boot rcupdate.rcu_task_stall_timeout=30000"
+		torture_set "clocksourcewd-3" tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 45s --configs TREE03 --trust-make
+	fi
+fi
+
 echo " --- " $scriptname $args
 echo " --- " Done `date` | tee -a $T/log
 ret=0
@@ -395,6 +418,10 @@ then
 	nfailures="`wc -l "$T/failures" | awk '{ print $1 }'`"
 	ret=2
 fi
+if test "$do_kcsan" = "yes"
+then
+	TORTURE_KCONFIG_KCSAN_ARG=1 tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh tools/testing/selftests/rcutorture/res/$ds > tools/testing/selftests/rcutorture/res/$ds/kcsan.sum
+fi
 echo Started at $startdate, ended at `date`, duration `get_starttime_duration $starttime`. | tee -a $T/log
 echo Summary: Successes: $nsuccesses Failures: $nfailures. | tee -a $T/log
 tdir="`cat $T/successes $T/failures | head -1 | awk '{ print $NF }' | sed -e 's,/[^/]\+/*$,,'`"
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/RUDE01 b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
index bafe94cbd739..3ca112444ce7 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
+++ b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
@@ -1,5 +1,5 @@
 CONFIG_SMP=y
-CONFIG_NR_CPUS=2
+CONFIG_NR_CPUS=4
 CONFIG_HOTPLUG_CPU=y
 CONFIG_PREEMPT_NONE=n
 CONFIG_PREEMPT_VOLUNTARY=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TASKS01 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS01
index bafe94cbd739..3ca112444ce7 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TASKS01
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TASKS01
@@ -1,5 +1,5 @@
 CONFIG_SMP=y
-CONFIG_NR_CPUS=2
+CONFIG_NR_CPUS=4
 CONFIG_HOTPLUG_CPU=y
 CONFIG_PREEMPT_NONE=n
 CONFIG_PREEMPT_VOLUNTARY=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TASKS03 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS03
index ea4399020c6c..dc02083803ce 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TASKS03
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TASKS03
@@ -1,5 +1,5 @@
 CONFIG_SMP=y
-CONFIG_NR_CPUS=2
+CONFIG_NR_CPUS=4
 CONFIG_PREEMPT_NONE=n
 CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=y