Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU changes from Paul E. McKenney:

 - Documentation updates.  Just some simple changes, no design-level
   additions.

 - Miscellaneous fixes.

 - Torture-test updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

5 files changed, 60 insertions, 17 deletions

diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh
index b325470c01b3..1426a9b97494 100644
--- a/tools/testing/selftests/rcutorture/bin/functions.sh
+++ b/tools/testing/selftests/rcutorture/bin/functions.sh
@@ -99,8 +99,9 @@ configfrag_hotplug_cpu () {
 # identify_boot_image qemu-cmd
 #
 # Returns the relative path to the kernel build image.  This will be
-# arch/<arch>/boot/bzImage unless overridden with the TORTURE_BOOT_IMAGE
-# environment variable.
+# arch/<arch>/boot/bzImage or vmlinux if bzImage is not a target for the
+# architecture, unless overridden with the TORTURE_BOOT_IMAGE environment
+# variable.
 identify_boot_image () {
 	if test -n "$TORTURE_BOOT_IMAGE"
 	then
@@ -110,11 +111,8 @@ identify_boot_image () {
 		qemu-system-x86_64|qemu-system-i386)
 			echo arch/x86/boot/bzImage
 			;;
-		qemu-system-ppc64)
-			echo arch/powerpc/boot/bzImage
-			;;
 		*)
-			echo ""
+			echo vmlinux
 			;;
 		esac
 	fi
@@ -175,7 +173,7 @@ identify_qemu_args () {
 	qemu-system-x86_64|qemu-system-i386)
 		;;
 	qemu-system-ppc64)
-		echo -enable-kvm -M pseries -cpu POWER7 -nodefaults
+		echo -enable-kvm -M pseries -nodefaults
 		echo -device spapr-vscsi
 		if test -n "$TORTURE_QEMU_INTERACTIVE" -a -n "$TORTURE_QEMU_MAC"
 		then
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
index 4109f306d855..ea6e373edc27 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -8,9 +8,9 @@
 #
 # Usage: kvm-test-1-run.sh config builddir resdir seconds qemu-args boot_args
 #
-# qemu-args defaults to "-enable-kvm -soundhw pcspk -nographic", along with
-#			arguments specifying the number of CPUs and other
-#			options generated from the underlying CPU architecture.
+# qemu-args defaults to "-enable-kvm -nographic", along with arguments
+#			specifying the number of CPUs and other options
+#			generated from the underlying CPU architecture.
 # boot_args defaults to value returned by the per_version_boot_params
 #			shell function.
 #
@@ -96,7 +96,8 @@ if test "$base_resdir" != "$resdir" -a -f $base_resdir/bzImage -a -f $base_resdi
 then
 	# Rerunning previous test, so use that test's kernel.
 	QEMU="`identify_qemu $base_resdir/vmlinux`"
-	KERNEL=$base_resdir/bzImage
+	BOOT_IMAGE="`identify_boot_image $QEMU`"
+	KERNEL=$base_resdir/${BOOT_IMAGE##*/} # use the last component of ${BOOT_IMAGE}
 	ln -s $base_resdir/Make*.out $resdir  # for kvm-recheck.sh
 	ln -s $base_resdir/.config $resdir  # for kvm-recheck.sh
 elif kvm-build.sh $config_template $builddir $T
@@ -110,7 +111,7 @@ then
 	if test -n "$BOOT_IMAGE"
 	then
 		cp $builddir/$BOOT_IMAGE $resdir
-		KERNEL=$resdir/bzImage
+		KERNEL=$resdir/${BOOT_IMAGE##*/}
 	else
 		echo No identifiable boot image, not running KVM, see $resdir.
 		echo Do the torture scripts know about your architecture?
@@ -147,7 +148,7 @@ then
 fi
 
 # Generate -smp qemu argument.
-qemu_args="-enable-kvm -soundhw pcspk -nographic $qemu_args"
+qemu_args="-enable-kvm -nographic $qemu_args"
 cpu_count=`configNR_CPUS.sh $config_template`
 cpu_count=`configfrag_boot_cpus "$boot_args" "$config_template" "$cpu_count"`
 vcpus=`identify_qemu_vcpus`
@@ -229,6 +230,7 @@ fi
 if test $commandcompleted -eq 0 -a -n "$qemu_pid"
 then
 	echo Grace period for qemu job at pid $qemu_pid
+	oldline="`tail $resdir/console.log`"
 	while :
 	do
 		kruntime=`awk 'BEGIN { print systime() - '"$kstarttime"' }' < /dev/null`
@@ -238,13 +240,29 @@ then
 		else
 			break
 		fi
-		if test $kruntime -ge $((seconds + $TORTURE_SHUTDOWN_GRACE))
+		must_continue=no
+		newline="`tail $resdir/console.log`"
+		if test "$newline" != "$oldline" && echo $newline | grep -q ' [0-9]\+us : '
+		then
+			must_continue=yes
+		fi
+		last_ts="`tail $resdir/console.log | grep '^\[ *[0-9]\+\.[0-9]\+]' | tail -1 | sed -e 's/^\[ *//' -e 's/\..*$//'`"
+		if test -z "last_ts"
+		then
+			last_ts=0
+		fi
+		if test "$newline" != "$oldline" -a "$last_ts" -lt $((seconds + $TORTURE_SHUTDOWN_GRACE))
+		then
+			must_continue=yes
+		fi
+		if test $must_continue = no -a $kruntime -ge $((seconds + $TORTURE_SHUTDOWN_GRACE))
 		then
 			echo "!!! PID $qemu_pid hung at $kruntime vs. $seconds seconds" >> $resdir/Warnings 2>&1
 			kill -KILL $qemu_pid
 			break
 		fi
-		sleep 1
+		oldline=$newline
+		sleep 10
 	done
 elif test -z "$qemu_pid"
 then
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 0d598145873e..0aed965f0062 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -48,7 +48,7 @@ resdir=""
 configs=""
 cpus=0
 ds=`date +%Y.%m.%d-%H:%M:%S`
-jitter=0
+jitter="-1"
 
 . functions.sh
 
diff --git a/tools/testing/selftests/rcutorture/bin/parse-console.sh b/tools/testing/selftests/rcutorture/bin/parse-console.sh
index 5eb49b7f864c..08aa7d50ae0e 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-console.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-console.sh
@@ -33,7 +33,7 @@ if grep -Pq '\x00' < $file
 then
 	print_warning Console output contains nul bytes, old qemu still running?
 fi
-egrep 'Badness|WARNING:|Warn|BUG|===========|Call Trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state' < $file | grep -v 'ODEBUG: ' | grep -v 'Warning: unable to open an initial console' > $1.diags
+egrep 'Badness|WARNING:|Warn|BUG|===========|Call Trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state|rcu_.*kthread starved for' < $file | grep -v 'ODEBUG: ' | grep -v 'Warning: unable to open an initial console' > $1.diags
 if test -s $1.diags
 then
 	print_warning Assertion failure in $file $title
@@ -69,6 +69,11 @@ then
 	then
 		summary="$summary  Stalls: $n_stalls"
 	fi
+	n_starves=`grep -c 'rcu_.*kthread starved for' $1`
+	if test "$n_starves" -ne 0
+	then
+		summary="$summary  Starves: $n_starves"
+	fi
 	print_warning Summary: $summary
 else
 	rm $1.diags
diff --git a/tools/testing/selftests/rcutorture/doc/initrd.txt b/tools/testing/selftests/rcutorture/doc/initrd.txt
index 4170e714f044..833f826d6ec2 100644
--- a/tools/testing/selftests/rcutorture/doc/initrd.txt
+++ b/tools/testing/selftests/rcutorture/doc/initrd.txt
@@ -13,6 +13,22 @@ cd initrd
 cpio -id < /tmp/initrd.img.zcat
 ------------------------------------------------------------------------
 
+Another way to create an initramfs image is using "dracut"[1], which is
+available on many distros, however the initramfs dracut generates is a cpio
+archive with another cpio archive in it, so an extra step is needed to create
+the initrd directory hierarchy.
+
+Here are the commands to create a initrd directory for rcutorture using
+dracut:
+
+------------------------------------------------------------------------
+dracut --no-hostonly --no-hostonly-cmdline --module "base bash shutdown" /tmp/initramfs.img
+cd tools/testing/selftests/rcutorture
+mkdir initrd
+cd initrd
+/usr/lib/dracut/skipcpio /tmp/initramfs.img | zcat | cpio -id < /tmp/initramfs.img
+------------------------------------------------------------------------
+
 Interestingly enough, if you are running rcutorture, you don't really
 need userspace in many cases.  Running without userspace has the
 advantage of allowing you to test your kernel independently of the
@@ -89,3 +105,9 @@ while :
 do
 	sleep 10
 done
+------------------------------------------------------------------------
+
+References:
+[1]: https://dracut.wiki.kernel.org/index.php/Main_Page
+[2]: http://blog.elastocloud.org/2015/06/rapid-linux-kernel-devtest-with-qemu.html
+[3]: https://www.centos.org/forums/viewtopic.php?t=51621