rcutorture: Don't rebuild identical kernel

Currently, if the user specifies multiple runs of a given test
configuration, the scripting does multiple kernel builds.  This wastes
both time and disk space, so this commit makes the scripting use the
first build for all runs of a given test configuration.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

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 73a2656..4109f30 100755 (executable)
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -91,25 +91,33 @@ fi
 # CONFIG_PCMCIA=n
 # CONFIG_CARDBUS=n
 # CONFIG_YENTA=n
-if kvm-build.sh $config_template $builddir $T
+base_resdir=`echo $resdir | sed -e 's/\.[0-9]\+$//'`
+if test "$base_resdir" != "$resdir" -a -f $base_resdir/bzImage -a -f $base_resdir/vmlinux
 then
+       # Rerunning previous test, so use that test's kernel.
+       QEMU="`identify_qemu $base_resdir/vmlinux`"
+       KERNEL=$base_resdir/bzImage
+       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
+then
+       # Had to build a kernel for this test.
        QEMU="`identify_qemu $builddir/vmlinux`"
        BOOT_IMAGE="`identify_boot_image $QEMU`"
        cp $builddir/Make*.out $resdir
+       cp $builddir/vmlinux $resdir
        cp $builddir/.config $resdir
        if test -n "$BOOT_IMAGE"
        then
                cp $builddir/$BOOT_IMAGE $resdir
+               KERNEL=$resdir/bzImage
        else
                echo No identifiable boot image, not running KVM, see $resdir.
                echo Do the torture scripts know about your architecture?
        fi
        parse-build.sh $resdir/Make.out $title
-       if test -f $builddir.wait
-       then
-               mv $builddir.wait $builddir.ready
-       fi
 else
+       # Build failed.
        cp $builddir/Make*.out $resdir
        cp $builddir/.config $resdir || :
        echo Build failed, not running KVM, see $resdir.
@@ -119,6 +127,10 @@ else
        fi
        exit 1
 fi
+if test -f $builddir.wait
+then
+       mv $builddir.wait $builddir.ready
+fi
 while test -f $builddir.ready
 do
        sleep 1
@@ -166,8 +178,8 @@ then
        exit 0
 fi
 echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log
-echo $QEMU $qemu_args -m 512 -kernel $resdir/bzImage -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd
-( $QEMU $qemu_args -m 512 -kernel $resdir/bzImage -append "$qemu_append $boot_args"& echo $! > $resdir/qemu_pid; wait `cat  $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) &
+echo $QEMU $qemu_args -m 512 -kernel $KERNEL -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd
+( $QEMU $qemu_args -m 512 -kernel $KERNEL -append "$qemu_append $boot_args"& echo $! > $resdir/qemu_pid; wait `cat  $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) &
 commandcompleted=0
 sleep 10 # Give qemu's pid a chance to reach the file
 if test -s "$resdir/qemu_pid"