rcutorture: Enable concurrent rcutorture runs

The rcutorture tests run by default range from using one CPU to using
sixteen of them.  Therefore, rcutorture testing could be sped up
significantly simply by running the kernels in parallel.  Building
them in parallel is not all that helpful: "make -j" is usually a
better bet.  So this commit takes a new "--cpus" argument that
specifies how many CPUs rcutorture is permitted to use for its
parallel runs.  The default of zero does sequential runs as before.

The bin-packing is minimal, and will be grossly suboptimal for
some configurations.  However, powers of two work reasonably well.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

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

@@ -96,6 +96,7 @@ identify_qemu () {
 		echo qemu-system-ppc64
 	else
 		echo Cannot figure out what qemu command to use! 1>&2
+		echo file $1 output: $u
 		# Usually this will be one of /usr/bin/qemu-system-*
 		# Use RCU_QEMU_CMD environment variable or appropriate
 		# argument to top-level script.

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

@@ -31,9 +31,9 @@ do
 	dirs=`find $rd -name Make.defconfig.out -print | sort | sed -e 's,/[^/]*$,,' | sort -u`
 	for i in $dirs
 	do
-		if test $firsttime
+		if test -n "$firsttime"
 		then
-			firsttime=0
+			firsttime=""
 			resdir=`echo $i | sed -e 's,/$,,' -e 's,/[^/]*$,,'`
 			head -1 $resdir/log
 		fi

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

@@ -123,7 +123,7 @@ kstarttime=`awk 'BEGIN { print systime() }' < /dev/null`
 echo ' ---' `date`: Starting kernel
 
 # Determine the appropriate flavor of qemu command.
-QEMU="`identify_qemu $builddir/vmlinux.o`"
+QEMU="`identify_qemu $builddir/vmlinux`"
 
 # Generate -smp qemu argument.
 qemu_args="-nographic $qemu_args"

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

@@ -30,6 +30,10 @@
 scriptname=$0
 args="$*"
 
+T=/tmp/kvm.sh.$$
+trap 'rm -rf $T' 0
+mkdir $T
+
 dur=30
 KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
 PATH=${KVM}/bin:$PATH; export PATH
@@ -38,6 +42,7 @@ RCU_INITRD="$KVM/initrd"; export RCU_INITRD
 RCU_KMAKE_ARG=""; export RCU_KMAKE_ARG
 resdir=""
 configs=""
+cpus=0
 ds=`date +%Y.%m.%d-%H:%M:%S`
 kversion=""
 
@@ -49,6 +54,7 @@ usage () {
 	echo "       --builddir absolute-pathname"
 	echo "       --buildonly"
 	echo "       --configs \"config-file list\""
+	echo "       --cpus N"
 	echo "       --datestamp string"
 	echo "       --duration minutes"
 	echo "       --interactive"
@@ -85,6 +91,11 @@ do
 		configs="$2"
 		shift
 		;;
+	--cpus)
+		checkarg --cpus "(number)" "$#" "$2" '^[0-9]*$' '^--'
+		cpus=$2
+		shift
+		;;
 	--datestamp)
 		checkarg --datestamp "(relative pathname)" "$#" "$2" '^[^/]*$' '^--'
 		ds=$2
@@ -168,6 +179,7 @@ else
 	fi
 fi
 mkdir $resdir/$ds
+echo Results directory: $resdir/$ds
 touch $resdir/$ds/log
 echo $scriptname $args
 echo $scriptname $args >> $resdir/$ds/log
@@ -178,33 +190,104 @@ then
 	git status >> $resdir/$ds/testid.txt
 	git rev-parse HEAD >> $resdir/$ds/testid.txt
 fi
-builddir=$KVM/b1
-if ! test -e $builddir
-then
-	mkdir $builddir || :
-fi
 
+touch $T/cfgcpu
 for CF in $configs
 do
-	# Running TREE01 multiple times creates TREE01, TREE01.2, TREE01.3, ...
-	rd=$resdir/$ds/$CF
-	if test -d "${rd}"
+	if test -f "$CONFIGFRAG/$kversion/$CF"
 	then
-		n="`ls -d "${rd}"* | grep '\.[0-9]\+$' |
-			sed -e 's/^.*\.\([0-9]\+\)/\1/' |
-			sort -k1n | tail -1`"
-		if test -z "$n"
-		then
-			rd="${rd}.2"
+		echo $CF `configNR_CPUS.sh $CONFIGFRAG/$kversion/$CF` >> $T/cfgcpu
 	else
-			n="`expr $n + 1`"
-			rd="${rd}.${n}"
+		echo "The --configs file $CF does not exist, terminating."
+		exit 1
 	fi
-	fi
-	mkdir "${rd}"
-	echo Results directory: $rd
-	kvm-test-1-rcu.sh $CONFIGFRAG/$kversion/$CF $builddir $rd $dur "$RCU_QEMU_ARG" "$RCU_BOOTARGS"
 done
+sort -k2nr $T/cfgcpu > $T/cfgcpu.sort
+
+awk < $T/cfgcpu.sort \
+	-v CONFIGDIR="$CONFIGFRAG/$kversion/" \
+	-v KVM="$KVM" \
+	-v ncpus=$cpus \
+	-v rd=$resdir/$ds/ \
+	-v dur=$dur \
+	-v RCU_QEMU_ARG=$RCU_QEMU_ARG \
+	-v RCU_BOOTARGS=$RCU_BOOTARGS \
+'BEGIN {
+	i = 0;
+}
+
+{
+	cf[i] = $1;
+	cpus[i] = $2;
+	i++;
+}
+
+function dump(first, pastlast)
+{
+	print "echo ----start batch----"
+	jn=1
+	for (j = first; j < pastlast; j++) {
+		builddir=KVM "/b" jn
+		print "echo ", cf[j], cpus[j] ": Starting build."
+		print "rm -f " builddir ".*"
+		print "touch " builddir ".wait"
+		print "mkdir " builddir " || :"
+		if (cfrep[cf[j]] == "") {
+			cfr[j] = cf[j];
+			cfrep[cf[j]] = 1;
+		} else {
+			cfrep[cf[j]]++;
+			cfr[j] = cf[j] "." cfrep[cf[j]];
+		}
+		print "mkdir " rd cfr[j] " || :";
+		print "kvm-test-1-rcu.sh " CONFIGDIR cf[j], builddir, rd cfr[j], dur " \"" RCU_QEMU_ARG "\" \"" RCU_BOOTARGS "\" > " builddir ".out 2>&1 &"
+		print "echo ", cf[j], cpus[j] ": Waiting for build to complete."
+		print "while test -f " builddir ".wait"
+		print "do"
+		print "\tsleep 1"
+		print "done"
+		print "echo ", cf[j], cpus[j] ": Build complete."
+		jn++;
+	}
+	k = first
+	for (j = 1; j < jn; j++) {
+		builddir=KVM "/b" j
+		print "rm -f " builddir ".ready"
+		print "echo ----", cf[k], cpus[k] ": Starting kernel"
+		k++;
+	}
+	print "wait"
+	print "echo ---- All kernel runs complete"
+	k = first
+	for (j = 1; j < jn; j++) {
+		builddir=KVM "/b" j
+		print "echo ----", cf[k], cpus[k] ": Build/run results:"
+		print "cat " builddir ".out"
+		k++;
+	}
+}
+
+END {
+	njobs = i;
+	nc = ncpus;
+	first = 0;
+	for (i = 0; i < njobs; i++) {
+		if (ncpus == 0) {
+			dump(i, i + 1);
+			first = i;
+		} else if (nc < cpus[i] && i != 0) {
+			dump(first, i);
+			first = i;
+			nc = ncpus;
+		}
+		nc -= cpus[i];
+	}
+	if (ncpus != 0)
+		dump(first, i);
+}' > $T/script
+
+sh $T/script
+
 # Tracing: trace_event=rcu:rcu_grace_period,rcu:rcu_future_grace_period,rcu:rcu_grace_period_init,rcu:rcu_nocb_wake,rcu:rcu_preempt_task,rcu:rcu_unlock_preempted_task,rcu:rcu_quiescent_state_report,rcu:rcu_fqs,rcu:rcu_callback,rcu:rcu_kfree_callback,rcu:rcu_batch_start,rcu:rcu_invoke_callback,rcu:rcu_invoke_kfree_callback,rcu:rcu_batch_end,rcu:rcu_torture_read,rcu:rcu_barrier
 
 echo " --- `date` Test summary:"