Merge branches 'fixes.2018.02.23a', 'srcu.2018.02.20a' and 'torture.2018.02.20a' into HEAD

fixes.2018.02.23a: Miscellaneous fixes
srcu.2018.02.20a: SRCU updates
torture.2018.02.20a: Torture-test updates

kernel/rcu/rcuperf.c

@@ -61,11 +61,30 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.vnet.ibm.com>");
 #define VERBOSE_PERFOUT_ERRSTRING(s) \
 	do { if (verbose) pr_alert("%s" PERF_FLAG "!!! %s\n", perf_type, s); } while (0)
 
+/*
+ * The intended use cases for the nreaders and nwriters module parameters
+ * are as follows:
+ *
+ * 1.	Specify only the nr_cpus kernel boot parameter.  This will
+ *	set both nreaders and nwriters to the value specified by
+ *	nr_cpus for a mixed reader/writer test.
+ *
+ * 2.	Specify the nr_cpus kernel boot parameter, but set
+ *	rcuperf.nreaders to zero.  This will set nwriters to the
+ *	value specified by nr_cpus for an update-only test.
+ *
+ * 3.	Specify the nr_cpus kernel boot parameter, but set
+ *	rcuperf.nwriters to zero.  This will set nreaders to the
+ *	value specified by nr_cpus for a read-only test.
+ *
+ * Various other use cases may of course be specified.
+ */
+
 torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives");
 torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader");
 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
 torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
-torture_param(int, nreaders, 0, "Number of RCU reader threads");
+torture_param(int, nreaders, -1, "Number of RCU reader threads");
 torture_param(int, nwriters, -1, "Number of RCU updater threads");
 torture_param(bool, shutdown, !IS_ENABLED(MODULE),
 	      "Shutdown at end of performance tests.");

kernel/rcu/rcutorture.c

@@ -909,34 +909,38 @@ rcu_torture_writer(void *arg)
 	int nsynctypes = 0;
 
 	VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
-	if (!can_expedite) {
+	if (!can_expedite)
 		pr_alert("%s" TORTURE_FLAG
-			 " GP expediting controlled from boot/sysfs for %s,\n",
+			 " GP expediting controlled from boot/sysfs for %s.\n",
 			 torture_type, cur_ops->name);
-		pr_alert("%s" TORTURE_FLAG
-			 " Disabled dynamic grace-period expediting.\n",
-			 torture_type);
-	}
 
 	/* Initialize synctype[] array.  If none set, take default. */
 	if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
 		gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
-	if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync)
+	if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync) {
 		synctype[nsynctypes++] = RTWS_COND_GET;
-	else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync))
-		pr_alert("rcu_torture_writer: gp_cond without primitives.\n");
-	if (gp_exp1 && cur_ops->exp_sync)
+		pr_info("%s: Testing conditional GPs.\n", __func__);
+	} else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync)) {
+		pr_alert("%s: gp_cond without primitives.\n", __func__);
+	}
+	if (gp_exp1 && cur_ops->exp_sync) {
 		synctype[nsynctypes++] = RTWS_EXP_SYNC;
-	else if (gp_exp && !cur_ops->exp_sync)
-		pr_alert("rcu_torture_writer: gp_exp without primitives.\n");
-	if (gp_normal1 && cur_ops->deferred_free)
+		pr_info("%s: Testing expedited GPs.\n", __func__);
+	} else if (gp_exp && !cur_ops->exp_sync) {
+		pr_alert("%s: gp_exp without primitives.\n", __func__);
+	}
+	if (gp_normal1 && cur_ops->deferred_free) {
 		synctype[nsynctypes++] = RTWS_DEF_FREE;
-	else if (gp_normal && !cur_ops->deferred_free)
-		pr_alert("rcu_torture_writer: gp_normal without primitives.\n");
-	if (gp_sync1 && cur_ops->sync)
+		pr_info("%s: Testing asynchronous GPs.\n", __func__);
+	} else if (gp_normal && !cur_ops->deferred_free) {
+		pr_alert("%s: gp_normal without primitives.\n", __func__);
+	}
+	if (gp_sync1 && cur_ops->sync) {
 		synctype[nsynctypes++] = RTWS_SYNC;
-	else if (gp_sync && !cur_ops->sync)
-		pr_alert("rcu_torture_writer: gp_sync without primitives.\n");
+		pr_info("%s: Testing normal GPs.\n", __func__);
+	} else if (gp_sync && !cur_ops->sync) {
+		pr_alert("%s: gp_sync without primitives.\n", __func__);
+	}
 	if (WARN_ONCE(nsynctypes == 0,
 		      "rcu_torture_writer: No update-side primitives.\n")) {
 		/*
@@ -1011,6 +1015,9 @@ rcu_torture_writer(void *arg)
 				rcu_unexpedite_gp();
 			if (++expediting > 3)
 				expediting = -expediting;
+		} else if (!can_expedite) { /* Disabled during boot, recheck. */
+			can_expedite = !rcu_gp_is_expedited() &&
+				       !rcu_gp_is_normal();
 		}
 		rcu_torture_writer_state = RTWS_STUTTER;
 		stutter_wait("rcu_torture_writer");
@@ -1021,6 +1028,10 @@ rcu_torture_writer(void *arg)
 	while (can_expedite && expediting++ < 0)
 		rcu_unexpedite_gp();
 	WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
+	if (!can_expedite)
+		pr_alert("%s" TORTURE_FLAG
+			 " Dynamic grace-period expediting was disabled.\n",
+			 torture_type);
 	rcu_torture_writer_state = RTWS_STOPPING;
 	torture_kthread_stopping("rcu_torture_writer");
 	return 0;
@@ -1045,13 +1056,13 @@ rcu_torture_fakewriter(void *arg)
 		    torture_random(&rand) % (nfakewriters * 8) == 0) {
 			cur_ops->cb_barrier();
 		} else if (gp_normal == gp_exp) {
-			if (torture_random(&rand) & 0x80)
+			if (cur_ops->sync && torture_random(&rand) & 0x80)
 				cur_ops->sync();
-			else
+			else if (cur_ops->exp_sync)
 				cur_ops->exp_sync();
-		} else if (gp_normal) {
+		} else if (gp_normal && cur_ops->sync) {
 			cur_ops->sync();
-		} else {
+		} else if (cur_ops->exp_sync) {
 			cur_ops->exp_sync();
 		}
 		stutter_wait("rcu_torture_fakewriter");
@@ -1557,11 +1568,10 @@ static int rcu_torture_barrier_init(void)
 	atomic_set(&barrier_cbs_count, 0);
 	atomic_set(&barrier_cbs_invoked, 0);
 	barrier_cbs_tasks =
-		kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]),
+		kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]),
 			GFP_KERNEL);
 	barrier_cbs_wq =
-		kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
-			GFP_KERNEL);
+		kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL);
 	if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
 		return -ENOMEM;
 	for (i = 0; i < n_barrier_cbs; i++) {
@@ -1674,7 +1684,7 @@ static void rcu_torture_err_cb(struct rcu_head *rhp)
 	 * next grace period.  Unlikely, but can happen.  If it
 	 * does happen, the debug-objects subsystem won't have splatted.
 	 */
-	pr_alert("rcutorture: duplicated callback was invoked.\n");
+	pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME);
 }
 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
 
@@ -1691,7 +1701,7 @@ static void rcu_test_debug_objects(void)
 
 	init_rcu_head_on_stack(&rh1);
 	init_rcu_head_on_stack(&rh2);
-	pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
+	pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME);
 
 	/* Try to queue the rh2 pair of callbacks for the same grace period. */
 	preempt_disable(); /* Prevent preemption from interrupting test. */
@@ -1706,11 +1716,11 @@ static void rcu_test_debug_objects(void)
 
 	/* Wait for them all to get done so we can safely return. */
 	rcu_barrier();
-	pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
+	pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
 	destroy_rcu_head_on_stack(&rh1);
 	destroy_rcu_head_on_stack(&rh2);
 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
-	pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
+	pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
 }
 
@@ -1799,7 +1809,7 @@ rcu_torture_init(void)
 	if (firsterr)
 		goto unwind;
 	if (nfakewriters > 0) {
-		fakewriter_tasks = kzalloc(nfakewriters *
+		fakewriter_tasks = kcalloc(nfakewriters,
 					   sizeof(fakewriter_tasks[0]),
 					   GFP_KERNEL);
 		if (fakewriter_tasks == NULL) {
@@ -1814,7 +1824,7 @@ rcu_torture_init(void)
 		if (firsterr)
 			goto unwind;
 	}
-	reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
+	reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
 			       GFP_KERNEL);
 	if (reader_tasks == NULL) {
 		VERBOSE_TOROUT_ERRSTRING("out of memory");

kernel/rcu/srcutree.c

@@ -386,7 +386,7 @@ void cleanup_srcu_struct(struct srcu_struct *sp)
 		flush_delayed_work(&per_cpu_ptr(sp->sda, cpu)->work);
 	if (WARN_ON(rcu_seq_state(READ_ONCE(sp->srcu_gp_seq)) != SRCU_STATE_IDLE) ||
 	    WARN_ON(srcu_readers_active(sp))) {
-		pr_info("cleanup_srcu_struct: Active srcu_struct %p state: %d\n", sp, rcu_seq_state(READ_ONCE(sp->srcu_gp_seq)));
+		pr_info("%s: Active srcu_struct %p state: %d\n", __func__, sp, rcu_seq_state(READ_ONCE(sp->srcu_gp_seq)));
 		return; /* Caller forgot to stop doing call_srcu()? */
 	}
 	free_percpu(sp->sda);
@@ -526,11 +526,11 @@ static void srcu_gp_end(struct srcu_struct *sp)
 {
 	unsigned long cbdelay;
 	bool cbs;
+	bool last_lvl;
 	int cpu;
 	unsigned long flags;
 	unsigned long gpseq;
 	int idx;
-	int idxnext;
 	unsigned long mask;
 	struct srcu_data *sdp;
 	struct srcu_node *snp;
@@ -554,11 +554,11 @@ static void srcu_gp_end(struct srcu_struct *sp)
 
 	/* Initiate callback invocation as needed. */
 	idx = rcu_seq_ctr(gpseq) % ARRAY_SIZE(snp->srcu_have_cbs);
-	idxnext = (idx + 1) % ARRAY_SIZE(snp->srcu_have_cbs);
 	rcu_for_each_node_breadth_first(sp, snp) {
 		spin_lock_irq_rcu_node(snp);
 		cbs = false;
-		if (snp >= sp->level[rcu_num_lvls - 1])
+		last_lvl = snp >= sp->level[rcu_num_lvls - 1];
+		if (last_lvl)
 			cbs = snp->srcu_have_cbs[idx] == gpseq;
 		snp->srcu_have_cbs[idx] = gpseq;
 		rcu_seq_set_state(&snp->srcu_have_cbs[idx], 1);
@@ -571,13 +571,16 @@ static void srcu_gp_end(struct srcu_struct *sp)
 			srcu_schedule_cbs_snp(sp, snp, mask, cbdelay);
 
 		/* Occasionally prevent srcu_data counter wrap. */
-		if (!(gpseq & counter_wrap_check))
+		if (!(gpseq & counter_wrap_check) && last_lvl)
 			for (cpu = snp->grplo; cpu <= snp->grphi; cpu++) {
 				sdp = per_cpu_ptr(sp->sda, cpu);
 				spin_lock_irqsave_rcu_node(sdp, flags);
 				if (ULONG_CMP_GE(gpseq,
 						 sdp->srcu_gp_seq_needed + 100))
 					sdp->srcu_gp_seq_needed = gpseq;
+				if (ULONG_CMP_GE(gpseq,
+						 sdp->srcu_gp_seq_needed_exp + 100))
+					sdp->srcu_gp_seq_needed_exp = gpseq;
 				spin_unlock_irqrestore_rcu_node(sdp, flags);
 			}
 	}
@@ -592,9 +595,7 @@ static void srcu_gp_end(struct srcu_struct *sp)
 	    ULONG_CMP_LT(gpseq, sp->srcu_gp_seq_needed)) {
 		srcu_gp_start(sp);
 		spin_unlock_irq_rcu_node(sp);
-		/* Throttle expedited grace periods: Should be rare! */
-		srcu_reschedule(sp, rcu_seq_ctr(gpseq) & 0x3ff
-				    ? 0 : SRCU_INTERVAL);
+		srcu_reschedule(sp, 0);
 	} else {
 		spin_unlock_irq_rcu_node(sp);
 	}

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

@@ -136,6 +136,9 @@ identify_boot_image () {
 		qemu-system-x86_64|qemu-system-i386)
 			echo arch/x86/boot/bzImage
 			;;
+		qemu-system-aarch64)
+			echo arch/arm64/boot/Image
+			;;
 		*)
 			echo vmlinux
 			;;
@@ -158,6 +161,9 @@ identify_qemu () {
 	elif echo $u | grep -q "Intel 80386"
 	then
 		echo qemu-system-i386
+	elif echo $u | grep -q aarch64
+	then
+		echo qemu-system-aarch64
 	elif uname -a | grep -q ppc64
 	then
 		echo qemu-system-ppc64
@@ -176,16 +182,20 @@ identify_qemu () {
 # Output arguments for the qemu "-append" string based on CPU type
 # and the TORTURE_QEMU_INTERACTIVE environment variable.
 identify_qemu_append () {
+	local console=ttyS0
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
 		echo noapic selinux=0 initcall_debug debug
 		;;
+	qemu-system-aarch64)
+		console=ttyAMA0
+		;;
 	esac
 	if test -n "$TORTURE_QEMU_INTERACTIVE"
 	then
 		echo root=/dev/sda
 	else
-		echo console=ttyS0
+		echo console=$console
 	fi
 }
 
@@ -197,6 +207,9 @@ identify_qemu_args () {
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
 		;;
+	qemu-system-aarch64)
+		echo -machine virt,gic-version=host -cpu host
+		;;
 	qemu-system-ppc64)
 		echo -enable-kvm -M pseries -nodefaults
 		echo -device spapr-vscsi
@@ -254,7 +267,7 @@ specify_qemu_cpus () {
 		echo $2
 	else
 		case "$1" in
-		qemu-system-x86_64|qemu-system-i386)
+		qemu-system-x86_64|qemu-system-i386|qemu-system-aarch64)
 			echo $2 -smp $3
 			;;
 		qemu-system-ppc64)

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

@@ -39,30 +39,31 @@ sed -e 's/us : / : /' |
 tr -d '\015' |
 awk '
 $8 == "start" {
-	if (starttask != "")
+	if (startseq != "")
 		nlost++;
 	starttask = $1;
 	starttime = $3;
 	startseq = $7;
+	seqtask[startseq] = starttask;
 }
 
 $8 == "end" {
-	if (starttask == $1 && startseq == $7) {
+	if (startseq == $7) {
 		curgpdur = $3 - starttime;
 		gptimes[++n] = curgpdur;
 		gptaskcnt[starttask]++;
 		sum += curgpdur;
 		if (curgpdur > 1000)
 			print "Long GP " starttime "us to " $3 "us (" curgpdur "us)";
-		starttask = "";
+		startseq = "";
 	} else {
 		# Lost a message or some such, reset.
-		starttask = "";
+		startseq = "";
 		nlost++;
 	}
 }
 
-$8 == "done" {
+$8 == "done" && seqtask[$7] != $1 {
 	piggybackcnt[$1]++;
 }
 

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

@@ -177,8 +177,8 @@ then
 	exit 0
 fi
 echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log
-echo $QEMU $qemu_args -m 512 -kernel $KERNEL -append \"$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 ) &
+echo $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd
+( $QEMU $qemu_args -m $TORTURE_QEMU_MEM -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"

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

@@ -1,10 +1,8 @@
 #!/bin/bash
 #
-# Run a series of 14 tests under KVM.  These are not particularly
-# well-selected or well-tuned, but are the current set.
-#
-# Edit the definitions below to set the locations of the various directories,
-# as well as the test duration.
+# Run a series of tests under KVM.  By default, this series is specified
+# by the relevant CFLIST file, but can be overridden by the --configs
+# command-line argument.
 #
 # Usage: kvm.sh [ options ]
 #
@@ -44,6 +42,7 @@ TORTURE_BOOT_IMAGE=""
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
 TORTURE_KCONFIG_ARG=""
 TORTURE_KMAKE_ARG=""
+TORTURE_QEMU_MEM=512
 TORTURE_SHUTDOWN_GRACE=180
 TORTURE_SUITE=rcu
 resdir=""
@@ -70,6 +69,7 @@ usage () {
 	echo "       --kconfig Kconfig-options"
 	echo "       --kmake-arg kernel-make-arguments"
 	echo "       --mac nn:nn:nn:nn:nn:nn"
+	echo "       --memory megabytes | nnnG"
 	echo "       --no-initrd"
 	echo "       --qemu-args qemu-arguments"
 	echo "       --qemu-cmd qemu-system-..."
@@ -147,6 +147,11 @@ do
 		TORTURE_QEMU_MAC=$2
 		shift
 		;;
+	--memory)
+		checkarg --memory "(memory size)" $# "$2" '^[0-9]\+[MG]\?$' error
+		TORTURE_QEMU_MEM=$2
+		shift
+		;;
 	--no-initrd)
 		TORTURE_INITRD=""; export TORTURE_INITRD
 		;;
@@ -174,6 +179,12 @@ do
 		checkarg --torture "(suite name)" "$#" "$2" '^\(lock\|rcu\|rcuperf\)$' '^--'
 		TORTURE_SUITE=$2
 		shift
+		if test "$TORTURE_SUITE" = rcuperf
+		then
+			# If you really want jitter for rcuperf, specify
+			# it after specifying rcuperf.  (But why?)
+			jitter=0
+		fi
 		;;
 	*)
 		echo Unknown argument $1
@@ -288,6 +299,7 @@ TORTURE_KMAKE_ARG="$TORTURE_KMAKE_ARG"; export TORTURE_KMAKE_ARG
 TORTURE_QEMU_CMD="$TORTURE_QEMU_CMD"; export TORTURE_QEMU_CMD
 TORTURE_QEMU_INTERACTIVE="$TORTURE_QEMU_INTERACTIVE"; export TORTURE_QEMU_INTERACTIVE
 TORTURE_QEMU_MAC="$TORTURE_QEMU_MAC"; export TORTURE_QEMU_MAC
+TORTURE_QEMU_MEM="$TORTURE_QEMU_MEM"; export TORTURE_QEMU_MEM
 TORTURE_SHUTDOWN_GRACE="$TORTURE_SHUTDOWN_GRACE"; export TORTURE_SHUTDOWN_GRACE
 TORTURE_SUITE="$TORTURE_SUITE"; export TORTURE_SUITE
 if ! test -e $resdir

tools/testing/selftests/rcutorture/configs/rcuperf/ver_functions.sh

@@ -20,32 +20,10 @@
 #
 # Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
 
-# rcuperf_param_nreaders bootparam-string
-#
-# Adds nreaders rcuperf module parameter if not already specified.
-rcuperf_param_nreaders () {
-	if ! echo "$1" | grep -q "rcuperf.nreaders"
-	then
-		echo rcuperf.nreaders=-1
-	fi
-}
-
-# rcuperf_param_nwriters bootparam-string
-#
-# Adds nwriters rcuperf module parameter if not already specified.
-rcuperf_param_nwriters () {
-	if ! echo "$1" | grep -q "rcuperf.nwriters"
-	then
-		echo rcuperf.nwriters=-1
-	fi
-}
-
 # per_version_boot_params bootparam-string config-file seconds
 #
 # Adds per-version torture-module parameters to kernels supporting them.
 per_version_boot_params () {
-	echo $1 `rcuperf_param_nreaders "$1"` \
-		`rcuperf_param_nwriters "$1"` \
-		rcuperf.shutdown=1 \
+	echo $1 rcuperf.shutdown=1 \
 		rcuperf.verbose=1
 }