rcutorture: Add dryrun capability

Actual rcutorture tests take considerable time and machine resources,
so it is inconvenient to actually do an rcutorture run when optimizing
the bin-packing algorithm.  This commit therefore adds a --dryrun
argument, which defaults to doing a run, but for which "sched"
says to simply print the run schedule and "script" dumps the script
without running it.

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

1 files changed, 35 insertions, 4 deletions

diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index f74f00628afe..9fab7c8e76f0 100644
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -35,6 +35,7 @@ trap 'rm -rf $T' 0
 mkdir $T
 
 dur=30
+dryrun=""
 KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
 PATH=${KVM}/bin:$PATH; export PATH
 builddir="${KVM}/b1"
@@ -56,6 +57,7 @@ usage () {
         echo "       --configs \"config-file list\""
         echo "       --cpus N"
         echo "       --datestamp string"
+        echo "       --dryrun sched|script"
         echo "       --duration minutes"
         echo "       --interactive"
         echo "       --kmake-arg kernel-make-arguments"
@@ -101,6 +103,11 @@ do
                 ds=$2
                 shift
                 ;;
+        --dryrun)
+                checkarg --dryrun "sched|script" $# "$2" 'sched\|script' '^--'
+                dryrun=$2
+                shift
+                ;;
         --duration)
                 checkarg --duration "(minutes)" $# "$2" '^[0-9]*$' '^error'
                 dur=$2
@@ -179,9 +186,12 @@ else
         fi
 fi
 mkdir $resdir/$ds
-echo Results directory: $resdir/$ds
+if test "$dryrun" = ""
+then
+        echo Results directory: $resdir/$ds
+        echo $scriptname $args
+fi
 touch $resdir/$ds/log
-echo $scriptname $args
 echo $scriptname $args >> $resdir/$ds/log
 
 pwd > $resdir/$ds/testid.txt
@@ -231,7 +241,7 @@ function dump(first, pastlast)
                 print "echo ", cf[j], cpus[j] ": Starting build."
                 print "rm -f " builddir ".*"
                 print "touch " builddir ".wait"
-                print "mkdir " builddir " || :"
+                print "mkdir " builddir " > /dev/null 2>&1 || :"
                 if (cfrep[cf[j]] == "") {
                         cfr[j] = cf[j];
                         cfrep[cf[j]] = 1;
@@ -286,7 +296,28 @@ END {
                 dump(first, i);
 }' > $T/script
 
-sh $T/script
+if test "$dryrun" = script
+then
+        echo CONFIGFRAG="$CONFIGFRAG; export CONFIGFRAG"
+        echo KVM="$KVM; export KVM"
+        echo KVPATH="$KVPATH; export KVPATH"
+        echo PATH="$PATH; export PATH"
+        echo RCU_BUILDONLY="$RCU_BUILDONLY; export RCU_BUILDONLY"
+        echo RCU_INITRD="$RCU_INITRD; export RCU_INITRD"
+        echo RCU_KMAKE_ARG="$RCU_KMAKE_ARG; export RCU_KMAKE_ARG"
+        echo RCU_QEMU_CMD="$RCU_QEMU_CMD; export RCU_QEMU_CMD"
+        echo RCU_QEMU_INTERACTIVE="$RCU_QEMU_INTERACTIVE; export RCU_QEMU_INTERACTIVE"
+        echo RCU_QEMU_MAC="$RCU_QEMU_MAC; export RCU_QEMU_MAC"
+        cat $T/script
+        exit 0
+elif test "$dryrun" = sched
+then
+        egrep 'start batch|Starting build\.' $T/script |
+                sed -e 's/:.*$//' -e 's/^echo //'
+        exit 0
+else
+        sh $T/script
+fi
 
 # 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