Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
 "The RCU changes in this cycle were:
   - Expedited grace-period updates
   - kfree_rcu() updates
   - RCU list updates
   - Preemptible RCU updates
   - Torture-test updates
   - Miscellaneous fixes
   - Documentation updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits)
  rcu: Remove unused stop-machine #include
  powerpc: Remove comment about read_barrier_depends()
  .mailmap: Add entries for old paulmck@kernel.org addresses
  srcu: Apply *_ONCE() to ->srcu_last_gp_end
  rcu: Switch force_qs_rnp() to for_each_leaf_node_cpu_mask()
  rcu: Move rcu_{expedited,normal} definitions into rcupdate.h
  rcu: Move gp_state_names[] and gp_state_getname() to tree_stall.h
  rcu: Remove the declaration of call_rcu() in tree.h
  rcu: Fix tracepoint tracking RCU CPU kthread utilization
  rcu: Fix harmless omission of "CONFIG_" from #if condition
  rcu: Avoid tick_dep_set_cpu() misordering
  rcu: Provide wrappers for uses of ->rcu_read_lock_nesting
  rcu: Use READ_ONCE() for ->expmask in rcu_read_unlock_special()
  rcu: Clear ->rcu_read_unlock_special only once
  rcu: Clear .exp_hint only when deferred quiescent state has been reported
  rcu: Rename some instance of CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU
  rcu: Remove kfree_call_rcu_nobatch()
  rcu: Remove kfree_rcu() special casing and lazy-callback handling
  rcu: Add support for debug_objects debugging for kfree_rcu()
  rcu: Add multiple in-flight batches of kfree_rcu() work
  ...

tools/testing/selftests/rcutorture/bin/cpus2use.sh

@@ -15,8 +15,15 @@ then
 	exit 0
 fi
 ncpus=`grep '^processor' /proc/cpuinfo | wc -l`
-idlecpus=`mpstat | tail -1 | \
-	awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'`
+if mpstat -V > /dev/null 2>&1
+then
+	idlecpus=`mpstat | tail -1 | \
+		awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'`
+else
+	# No mpstat command, so use all available CPUs.
+	echo The mpstat command is not available, so greedily using all CPUs.
+	idlecpus=$ncpus
+fi
 awk -v ncpus=$ncpus -v idlecpus=$idlecpus < /dev/null '
 BEGIN {
 	cpus2use = idlecpus;

tools/testing/selftests/rcutorture/bin/jitter.sh

@@ -23,25 +23,39 @@ spinmax=${4-1000}
 
 n=1
 
-starttime=`awk 'BEGIN { print systime(); }' < /dev/null`
+starttime=`gawk 'BEGIN { print systime(); }' < /dev/null`
+
+nohotplugcpus=
+for i in /sys/devices/system/cpu/cpu[0-9]*
+do
+	if test -f $i/online
+	then
+		:
+	else
+		curcpu=`echo $i | sed -e 's/^[^0-9]*//'`
+		nohotplugcpus="$nohotplugcpus $curcpu"
+	fi
+done
 
 while :
 do
 	# Check for done.
-	t=`awk -v s=$starttime 'BEGIN { print systime() - s; }' < /dev/null`
+	t=`gawk -v s=$starttime 'BEGIN { print systime() - s; }' < /dev/null`
 	if test "$t" -gt "$duration"
 	then
 		exit 0;
 	fi
 
 	# Set affinity to randomly selected online CPU
-	cpus=`grep 1 /sys/devices/system/cpu/*/online |
-		sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//'`
-
-	# Do not leave out poor old cpu0 which may not be hot-pluggable
-	if [ ! -f "/sys/devices/system/cpu/cpu0/online" ]; then
-		cpus="0 $cpus"
+	if cpus=`grep 1 /sys/devices/system/cpu/*/online 2>&1 |
+		 sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//'`
+	then
+		:
+	else
+		cpus=
 	fi
+	# Do not leave out non-hot-pluggable CPUs
+	cpus="$cpus $nohotplugcpus"
 
 	cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN {
 		srand(n + me + systime());

tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh

@@ -25,6 +25,7 @@ stopstate="`grep 'End-test grace-period state: g' $i/console.log 2> /dev/null |
 	    tail -1 | sed -e 's/^\[[ 0-9.]*] //' |
 	    awk '{ print \"[\" $1 \" \" $5 \" \" $6 \" \" $7 \"]\"; }' |
 	    tr -d '\012\015'`"
+fwdprog="`grep 'rcu_torture_fwd_prog_cr Duration' $i/console.log 2> /dev/null | sed -e 's/^\[[^]]*] //' | sort -k15nr | head -1 | awk '{ print $14 " " $15 }'`"
 if test -z "$ngps"
 then
 	echo "$configfile ------- " $stopstate
@@ -39,7 +40,7 @@ else
 			BEGIN { print ngps / dur }' < /dev/null`
 		title="$title ($ngpsps/s)"
 	fi
-	echo $title $stopstate
+	echo $title $stopstate $fwdprog
 	nclosecalls=`grep --binary-files=text 'torture: Reader Batch' $i/console.log | tail -1 | awk '{for (i=NF-8;i<=NF;i++) sum+=$i; } END {print sum}'`
 	if test -z "$nclosecalls"
 	then

tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh

@@ -123,7 +123,7 @@ qemu_args=$5
 boot_args=$6
 
 cd $KVM
-kstarttime=`awk 'BEGIN { print systime() }' < /dev/null`
+kstarttime=`gawk 'BEGIN { print systime() }' < /dev/null`
 if test -z "$TORTURE_BUILDONLY"
 then
 	echo ' ---' `date`: Starting kernel
@@ -133,11 +133,10 @@ fi
 qemu_args="-enable-kvm -nographic $qemu_args"
 cpu_count=`configNR_CPUS.sh $resdir/ConfigFragment`
 cpu_count=`configfrag_boot_cpus "$boot_args" "$config_template" "$cpu_count"`
-vcpus=`identify_qemu_vcpus`
-if test $cpu_count -gt $vcpus
+if test "$cpu_count" -gt "$TORTURE_ALLOTED_CPUS"
 then
-	echo CPU count limited from $cpu_count to $vcpus | tee -a $resdir/Warnings
-	cpu_count=$vcpus
+	echo CPU count limited from $cpu_count to $TORTURE_ALLOTED_CPUS | tee -a $resdir/Warnings
+	cpu_count=$TORTURE_ALLOTED_CPUS
 fi
 qemu_args="`specify_qemu_cpus "$QEMU" "$qemu_args" "$cpu_count"`"
 
@@ -177,7 +176,7 @@ do
 	then
 		qemu_pid=`cat "$resdir/qemu_pid"`
 	fi
-	kruntime=`awk 'BEGIN { print systime() - '"$kstarttime"' }' < /dev/null`
+	kruntime=`gawk 'BEGIN { print systime() - '"$kstarttime"' }' < /dev/null`
 	if test -z "$qemu_pid" || kill -0 "$qemu_pid" > /dev/null 2>&1
 	then
 		if test $kruntime -ge $seconds
@@ -213,7 +212,7 @@ then
 	oldline="`tail $resdir/console.log`"
 	while :
 	do
-		kruntime=`awk 'BEGIN { print systime() - '"$kstarttime"' }' < /dev/null`
+		kruntime=`gawk 'BEGIN { print systime() - '"$kstarttime"' }' < /dev/null`
 		if kill -0 $qemu_pid > /dev/null 2>&1
 		then
 			:

tools/testing/selftests/rcutorture/bin/kvm.sh

@@ -24,7 +24,9 @@ dur=$((30*60))
 dryrun=""
 KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
 PATH=${KVM}/bin:$PATH; export PATH
-TORTURE_ALLOTED_CPUS=""
+. functions.sh
+
+TORTURE_ALLOTED_CPUS="`identify_qemu_vcpus`"
 TORTURE_DEFCONFIG=defconfig
 TORTURE_BOOT_IMAGE=""
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
@@ -40,8 +42,6 @@ cpus=0
 ds=`date +%Y.%m.%d-%H:%M:%S`
 jitter="-1"
 
-. functions.sh
-
 usage () {
 	echo "Usage: $scriptname optional arguments:"
 	echo "       --bootargs kernel-boot-arguments"
@@ -93,6 +93,11 @@ do
 		checkarg --cpus "(number)" "$#" "$2" '^[0-9]*$' '^--'
 		cpus=$2
 		TORTURE_ALLOTED_CPUS="$2"
+		max_cpus="`identify_qemu_vcpus`"
+		if test "$TORTURE_ALLOTED_CPUS" -gt "$max_cpus"
+		then
+			TORTURE_ALLOTED_CPUS=$max_cpus
+		fi
 		shift
 		;;
 	--datestamp)
@@ -198,9 +203,10 @@ fi
 
 CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
 
+defaultconfigs="`tr '\012' ' ' < $CONFIGFRAG/CFLIST`"
 if test -z "$configs"
 then
-	configs="`cat $CONFIGFRAG/CFLIST`"
+	configs=$defaultconfigs
 fi
 
 if test -z "$resdir"
@@ -209,7 +215,7 @@ then
 fi
 
 # Create a file of test-name/#cpus pairs, sorted by decreasing #cpus.
-touch $T/cfgcpu
+configs_derep=
 for CF in $configs
 do
 	case $CF in
@@ -222,15 +228,21 @@ do
 		CF1=$CF
 		;;
 	esac
+	for ((cur_rep=0;cur_rep<$config_reps;cur_rep++))
+	do
+		configs_derep="$configs_derep $CF1"
+	done
+done
+touch $T/cfgcpu
+configs_derep="`echo $configs_derep | sed -e "s/\<CFLIST\>/$defaultconfigs/g"`"
+for CF1 in $configs_derep
+do
 	if test -f "$CONFIGFRAG/$CF1"
 	then
 		cpu_count=`configNR_CPUS.sh $CONFIGFRAG/$CF1`
 		cpu_count=`configfrag_boot_cpus "$TORTURE_BOOTARGS" "$CONFIGFRAG/$CF1" "$cpu_count"`
 		cpu_count=`configfrag_boot_maxcpus "$TORTURE_BOOTARGS" "$CONFIGFRAG/$CF1" "$cpu_count"`
-		for ((cur_rep=0;cur_rep<$config_reps;cur_rep++))
-		do
-			echo $CF1 $cpu_count >> $T/cfgcpu
-		done
+		echo $CF1 $cpu_count >> $T/cfgcpu
 	else
 		echo "The --configs file $CF1 does not exist, terminating."
 		exit 1

tools/testing/selftests/rcutorture/bin/mkinitrd.sh

@@ -20,58 +20,9 @@ if [ -s "$D/initrd/init" ]; then
     exit 0
 fi
 
-T=${TMPDIR-/tmp}/mkinitrd.sh.$$
-trap 'rm -rf $T' 0 2
-mkdir $T
-
-cat > $T/init << '__EOF___'
-#!/bin/sh
-# Run in userspace a few milliseconds every second.  This helps to
-# exercise the NO_HZ_FULL portions of RCU.  The 192 instances of "a" was
-# empirically shown to give a nice multi-millisecond burst of user-mode
-# execution on a 2GHz CPU, as desired.  Modern CPUs will vary from a
-# couple of milliseconds up to perhaps 100 milliseconds, which is an
-# acceptable range.
-#
-# Why not calibrate an exact delay?  Because within this initrd, we
-# are restricted to Bourne-shell builtins, which as far as I know do not
-# provide any means of obtaining a fine-grained timestamp.
-
-a4="a a a a"
-a16="$a4 $a4 $a4 $a4"
-a64="$a16 $a16 $a16 $a16"
-a192="$a64 $a64 $a64"
-while :
-do
-	q=
-	for i in $a192
-	do
-		q="$q $i"
-	done
-	sleep 1
-done
-__EOF___
-
-# Try using dracut to create initrd
-if command -v dracut >/dev/null 2>&1
-then
-	echo Creating $D/initrd using dracut.
-	# Filesystem creation
-	dracut --force --no-hostonly --no-hostonly-cmdline --module "base" $T/initramfs.img
-	cd $D
-	mkdir -p initrd
-	cd initrd
-	zcat $T/initramfs.img | cpio -id
-	cp $T/init init
-	chmod +x init
-	echo Done creating $D/initrd using dracut
-	exit 0
-fi
-
-# No dracut, so create a C-language initrd/init program and statically
-# link it.  This results in a very small initrd, but might be a bit less
-# future-proof than dracut.
-echo "Could not find dracut, attempting C initrd"
+# Create a C-language initrd/init infinite-loop program and statically
+# link it.  This results in a very small initrd.
+echo "Creating a statically linked C-language initrd"
 cd $D
 mkdir -p initrd
 cd initrd