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* [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3
@ 2019-05-30 15:16 Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 01/21] rcutorture: Select from only online CPUs Paul E. McKenney
                   ` (20 more replies)
  0 siblings, 21 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel

Hello!

This series contains torture-test updates:

1.	Make jitter.sh select from only online CPUs, courtesy of
	Joel Fernandes.

2.	Add cpu0 to the set of CPUs to add jitter, courtesy of Joel
	Fernandes.

3.	Add cond_resched() to forward-progress free-up loop.

4.	Fix stutter_wait() return value and freelist checks.

5.	Allow inter-stutter interval to be specified.

6.	Make kvm-find-errors.sh and kvm-recheck.sh provide exit status.

7.	Provide rudimentary Makefile.

8.	Exempt tasks RCU from timely draining of grace periods.

9.	Exempt TREE01 from forward-progress testing.

10.	Give the scheduler a chance on PREEMPT && NO_HZ_FULL kernels.

11.	Halt forward-progress checks at end of run.

12.	Add trivial RCU implementation.

13.	Tweak kvm options, courtesy of Sebastian Andrzej Siewior.

14.	Capture qemu output.

15.	Add function graph-tracing cheat sheet.

16.	Run kernel build in source directory.

17.	Make --cpus override idleness calculations.

18.	Add --trust-make to suppress "make clean".

19.	Dump trace buffer for callback pipe drain failures.

20.	Suppress propagating trace_printk() warning.

21.	Upper case solves the case of the vanishing NULL pointer.

							Thanx, Paul

------------------------------------------------------------------------

 include/linux/torture.h                                     |    2 
 kernel/locking/locktorture.c                                |    2 
 kernel/rcu/rcu.h                                            |    5 
 kernel/rcu/rcutorture.c                                     |  104 ++++++++++--
 kernel/rcu/update.c                                         |   13 +
 kernel/torture.c                                            |   23 +-
 tools/testing/selftests/rcutorture/Makefile                 |    3 
 tools/testing/selftests/rcutorture/bin/configinit.sh        |   41 +---
 tools/testing/selftests/rcutorture/bin/cpus2use.sh          |    5 
 tools/testing/selftests/rcutorture/bin/functions.sh         |   13 +
 tools/testing/selftests/rcutorture/bin/jitter.sh            |   13 +
 tools/testing/selftests/rcutorture/bin/kvm-build.sh         |    9 -
 tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh   |    3 
 tools/testing/selftests/rcutorture/bin/kvm-recheck.sh       |   13 +
 tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh    |   23 +-
 tools/testing/selftests/rcutorture/bin/kvm.sh               |   14 +
 tools/testing/selftests/rcutorture/bin/parse-build.sh       |    2 
 tools/testing/selftests/rcutorture/bin/parse-console.sh     |    1 
 tools/testing/selftests/rcutorture/configs/rcu/CFcommon     |    3 
 tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot  |    1 
 tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL      |   14 +
 tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot |    3 
 22 files changed, 231 insertions(+), 79 deletions(-)


^ permalink raw reply	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 01/21] rcutorture: Select from only online CPUs
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 02/21] rcutorture: Add cpu0 to the set of CPUs to add jitter Paul E. McKenney
                   ` (19 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E . McKenney

From: "Joel Fernandes (Google)" <joel@joelfernandes.org>

The rcutorture jitter.sh script selects a random CPU but does not check
if it is offline or online. This leads to taskset errors many times. On
my machine, hyper threading is disabled so half the cores are offline
causing taskset errors a lot of times. Let us fix this by checking from
only the online CPUs on the system.

Cc: rcu@vger.kernel.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/jitter.sh | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rcutorture/bin/jitter.sh b/tools/testing/selftests/rcutorture/bin/jitter.sh
index 435b60933985..81c6e6ab5d83 100755
--- a/tools/testing/selftests/rcutorture/bin/jitter.sh
+++ b/tools/testing/selftests/rcutorture/bin/jitter.sh
@@ -34,10 +34,11 @@ do
 		exit 0;
 	fi
 
-	# Set affinity to randomly selected CPU
-	cpus=`ls /sys/devices/system/cpu/*/online |
+	# Set affinity to randomly selected online CPU
+	cpus=`grep 1 /sys/devices/system/cpu/*/online |
 		sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//' |
 		grep -v '^0*$'`
+
 	cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN {
 		srand(n + me + systime());
 		ncpus = split(cpus, ca);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 02/21] rcutorture: Add cpu0 to the set of CPUs to add jitter
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 01/21] rcutorture: Select from only online CPUs Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 03/21] rcutorture: Add cond_resched() to forward-progress free-up loop Paul E. McKenney
                   ` (18 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E . McKenney

From: "Joel Fernandes (Google)" <joel@joelfernandes.org>

jitter.sh currently does not add CPU0 to the list of CPUs for adding of
jitter. Let us add it to this list even when it is not hot-pluggable.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/jitter.sh | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rcutorture/bin/jitter.sh b/tools/testing/selftests/rcutorture/bin/jitter.sh
index 81c6e6ab5d83..dc49a3ba6111 100755
--- a/tools/testing/selftests/rcutorture/bin/jitter.sh
+++ b/tools/testing/selftests/rcutorture/bin/jitter.sh
@@ -36,8 +36,12 @@ do
 
 	# Set affinity to randomly selected online CPU
 	cpus=`grep 1 /sys/devices/system/cpu/*/online |
-		sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//' |
-		grep -v '^0*$'`
+		sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//'`
+
+	# Do not leave out poor old cpu0 which may not be hot-pluggable
+	if [ ! -f "/sys/devices/system/cpu/cpu0/online" ]; then
+		cpus="0 $cpus"
+	fi
 
 	cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN {
 		srand(n + me + systime());
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 03/21] rcutorture: Add cond_resched() to forward-progress free-up loop
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 01/21] rcutorture: Select from only online CPUs Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 02/21] rcutorture: Add cpu0 to the set of CPUs to add jitter Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 04/21] rcutorture: Fix stutter_wait() return value and freelist checks Paul E. McKenney
                   ` (17 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

The rcu_torture_fwd_prog_cbfree() function frees callbacks used during
rcutorture's call_rcu() forward-progress test, but does so in a tight
loop.  This could cause problems given a very long list of callbacks to be
freed, and actual testing produces lists with as many as 25M callbacks.
This commit therefore adds a cond_resched() to this loop.  While in
the area, this commit also rearranges the lock releases to look a bit
more sane.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 kernel/rcu/rcutorture.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index efaa5b3f4d3f..7906ba2d9dad 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1674,16 +1674,18 @@ static unsigned long rcu_torture_fwd_prog_cbfree(void)
 	for (;;) {
 		spin_lock_irqsave(&rcu_fwd_lock, flags);
 		rfcp = rcu_fwd_cb_head;
-		if (!rfcp)
+		if (!rfcp) {
+			spin_unlock_irqrestore(&rcu_fwd_lock, flags);
 			break;
+		}
 		rcu_fwd_cb_head = rfcp->rfc_next;
 		if (!rcu_fwd_cb_head)
 			rcu_fwd_cb_tail = &rcu_fwd_cb_head;
 		spin_unlock_irqrestore(&rcu_fwd_lock, flags);
 		kfree(rfcp);
 		freed++;
+		cond_resched();
 	}
-	spin_unlock_irqrestore(&rcu_fwd_lock, flags);
 	return freed;
 }
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 04/21] rcutorture: Fix stutter_wait() return value and freelist checks
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (2 preceding siblings ...)
  2019-05-30 15:16 ` [PATCH tip/core/rcu 03/21] rcutorture: Add cond_resched() to forward-progress free-up loop Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 05/21] torture: Allow inter-stutter interval to be specified Paul E. McKenney
                   ` (16 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

The stutter_wait() function is supposed to return true if it actually
waits and false otherwise, but it instead unconditionally returns false.
Which hides a bug in rcu_torture_writer() that fails to account for
the fact that one of the rcu_tortures[] array elements will normally be
referenced by rcu_torture_current, and thus not be on the freelist.

This commit therefore corrects the stutter_wait() return value and adds a
check for rcu_torture_current to rcu_torture_writer()'s check that things
get freed after everything goes quiescent.  In addition, this commit
causes torture_stutter() to give a bit more than one second (instead of
only one jiffy) warning of the end of the stutter interval.  Finally,
this commit disables long-delay readers and aggressive update-side
forward-progress checks while forward-progress testing is in flight.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 kernel/rcu/rcutorture.c | 16 ++++++++++++----
 kernel/torture.c        | 17 +++++++++++++----
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 7906ba2d9dad..954ac2b98619 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1010,10 +1010,13 @@ rcu_torture_writer(void *arg)
 				       !rcu_gp_is_normal();
 		}
 		rcu_torture_writer_state = RTWS_STUTTER;
-		if (stutter_wait("rcu_torture_writer"))
+		if (stutter_wait("rcu_torture_writer") &&
+		    !READ_ONCE(rcu_fwd_cb_nodelay))
 			for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)
-				if (list_empty(&rcu_tortures[i].rtort_free))
-					WARN_ON_ONCE(1);
+				if (list_empty(&rcu_tortures[i].rtort_free) &&
+				    rcu_access_pointer(rcu_torture_current) !=
+				    &rcu_tortures[i])
+					WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
 	} while (!torture_must_stop());
 	/* Reset expediting back to unexpedited. */
 	if (expediting > 0)
@@ -1709,6 +1712,8 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)
 	}
 
 	/* Tight loop containing cond_resched(). */
+	WRITE_ONCE(rcu_fwd_cb_nodelay, true);
+	cur_ops->sync(); /* Later readers see above write. */
 	if  (selfpropcb) {
 		WRITE_ONCE(fcs.stop, 0);
 		cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb);
@@ -1747,6 +1752,8 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)
 		WARN_ON(READ_ONCE(fcs.stop) != 2);
 		destroy_rcu_head_on_stack(&fcs.rh);
 	}
+	schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */
+	WRITE_ONCE(rcu_fwd_cb_nodelay, false);
 }
 
 /* Carry out call_rcu() forward-progress testing. */
@@ -1816,7 +1823,6 @@ static void rcu_torture_fwd_prog_cr(void)
 	cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */
 	(void)rcu_torture_fwd_prog_cbfree();
 
-	WRITE_ONCE(rcu_fwd_cb_nodelay, false);
 	if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop)) {
 		WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED);
 		pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n",
@@ -1827,6 +1833,8 @@ static void rcu_torture_fwd_prog_cr(void)
 			 n_max_gps, n_max_cbs, cver, gps);
 		rcu_torture_fwd_cb_hist();
 	}
+	schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */
+	WRITE_ONCE(rcu_fwd_cb_nodelay, false);
 }
 
 
diff --git a/kernel/torture.c b/kernel/torture.c
index 17b2be9bde12..de0e0ecf88e1 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -578,10 +578,12 @@ static int stutter;
 bool stutter_wait(const char *title)
 {
 	int spt;
+	bool ret = false;
 
 	cond_resched_tasks_rcu_qs();
 	spt = READ_ONCE(stutter_pause_test);
 	for (; spt; spt = READ_ONCE(stutter_pause_test)) {
+		ret = true;
 		if (spt == 1) {
 			schedule_timeout_interruptible(1);
 		} else if (spt == 2) {
@@ -592,7 +594,7 @@ bool stutter_wait(const char *title)
 		}
 		torture_shutdown_absorb(title);
 	}
-	return !!spt;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(stutter_wait);
 
@@ -602,13 +604,20 @@ EXPORT_SYMBOL_GPL(stutter_wait);
  */
 static int torture_stutter(void *arg)
 {
+	int wtime;
+
 	VERBOSE_TOROUT_STRING("torture_stutter task started");
 	do {
 		if (!torture_must_stop() && stutter > 1) {
-			WRITE_ONCE(stutter_pause_test, 1);
-			schedule_timeout_interruptible(stutter - 1);
+			wtime = stutter;
+			if (stutter > HZ + 1) {
+				WRITE_ONCE(stutter_pause_test, 1);
+				wtime = stutter - HZ - 1;
+				schedule_timeout_interruptible(wtime);
+				wtime = HZ + 1;
+			}
 			WRITE_ONCE(stutter_pause_test, 2);
-			schedule_timeout_interruptible(1);
+			schedule_timeout_interruptible(wtime);
 		}
 		WRITE_ONCE(stutter_pause_test, 0);
 		if (!torture_must_stop())
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 05/21] torture: Allow inter-stutter interval to be specified
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (3 preceding siblings ...)
  2019-05-30 15:16 ` [PATCH tip/core/rcu 04/21] rcutorture: Fix stutter_wait() return value and freelist checks Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 06/21] torture: Make kvm-find-errors.sh and kvm-recheck.sh provide exit status Paul E. McKenney
                   ` (15 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Currently, the inter-stutter interval is the same as the stutter duration,
that is, whatever number of jiffies is passed into torture_stutter_init().
This has worked well for quite some time, but the addition of
forward-progress testing to rcutorture can delay processes for several
seconds, which can triple the time that they are stuttered.

This commit therefore adds a second argument to torture_stutter_init()
that specifies the inter-stutter interval.  While locktorture preserves
the current behavior, rcutorture uses the RCU CPU stall warning interval
to provide a wider inter-stutter interval.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 include/linux/torture.h      | 2 +-
 kernel/locking/locktorture.c | 2 +-
 kernel/rcu/rcutorture.c      | 5 ++++-
 kernel/torture.c             | 6 ++++--
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/include/linux/torture.h b/include/linux/torture.h
index 23d80db426d7..a620118385bb 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -66,7 +66,7 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void));
 
 /* Task stuttering, which forces load/no-load transitions. */
 bool stutter_wait(const char *title);
-int torture_stutter_init(int s);
+int torture_stutter_init(int s, int sgap);
 
 /* Initialization and cleanup. */
 bool torture_init_begin(char *ttype, int v);
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 80a463d31a8d..c513031cd7e3 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -975,7 +975,7 @@ static int __init lock_torture_init(void)
 			goto unwind;
 	}
 	if (stutter > 0) {
-		firsterr = torture_stutter_init(stutter);
+		firsterr = torture_stutter_init(stutter, stutter);
 		if (firsterr)
 			goto unwind;
 	}
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 954ac2b98619..a16d6abe1715 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -2373,7 +2373,10 @@ rcu_torture_init(void)
 	if (stutter < 0)
 		stutter = 0;
 	if (stutter) {
-		firsterr = torture_stutter_init(stutter * HZ);
+		int t;
+
+		t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ;
+		firsterr = torture_stutter_init(stutter * HZ, t);
 		if (firsterr)
 			goto unwind;
 	}
diff --git a/kernel/torture.c b/kernel/torture.c
index de0e0ecf88e1..a8d9bdfba7c3 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -570,6 +570,7 @@ static void torture_shutdown_cleanup(void)
 static struct task_struct *stutter_task;
 static int stutter_pause_test;
 static int stutter;
+static int stutter_gap;
 
 /*
  * Block until the stutter interval ends.  This must be called periodically
@@ -621,7 +622,7 @@ static int torture_stutter(void *arg)
 		}
 		WRITE_ONCE(stutter_pause_test, 0);
 		if (!torture_must_stop())
-			schedule_timeout_interruptible(stutter);
+			schedule_timeout_interruptible(stutter_gap);
 		torture_shutdown_absorb("torture_stutter");
 	} while (!torture_must_stop());
 	torture_kthread_stopping("torture_stutter");
@@ -631,9 +632,10 @@ static int torture_stutter(void *arg)
 /*
  * Initialize and kick off the torture_stutter kthread.
  */
-int torture_stutter_init(const int s)
+int torture_stutter_init(const int s, const int sgap)
 {
 	stutter = s;
+	stutter_gap = sgap;
 	return torture_create_kthread(torture_stutter, NULL, stutter_task);
 }
 EXPORT_SYMBOL_GPL(torture_stutter_init);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 06/21] torture: Make kvm-find-errors.sh and kvm-recheck.sh provide exit status
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (4 preceding siblings ...)
  2019-05-30 15:16 ` [PATCH tip/core/rcu 05/21] torture: Allow inter-stutter interval to be specified Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 07/21] rcutorture: Provide rudimentary Makefile Paul E. McKenney
                   ` (14 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

This commit causes both kvm-find-errors.sh and kvm-recheck.sh to provide
an exit status based on whether or not errors were located.  In the
case of kvm-recheck.sh, this will be the error status of the last run.
This change allows these commands to be used in scripting and Makefiles
to automatically report failed rcutorture runs.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh | 3 +++
 tools/testing/selftests/rcutorture/bin/kvm-recheck.sh     | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
index 8426fe1f15ee..1871d00bccd7 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
@@ -11,6 +11,7 @@
 #
 # The "directory" above should end with the date/time directory, for example,
 # "tools/testing/selftests/rcutorture/res/2018.02.25-14:27:27".
+# Returns error status reflecting the success (or not) of the specified run.
 #
 # Copyright (C) IBM Corporation, 2018
 #
@@ -56,6 +57,8 @@ done
 if test -n "$files"
 then
 	$editor $files
+	exit 1
 else
 	echo No errors in console logs.
+	exit 0
 fi
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
index 2adde6aaafdb..2297ddc2d4c5 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
@@ -7,6 +7,8 @@
 #
 # Usage: kvm-recheck.sh resdir ...
 #
+# Returns status reflecting the success or not of the last run specified.
+#
 # Copyright (C) IBM Corporation, 2011
 #
 # Authors: Paul E. McKenney <paulmck@linux.ibm.com>
@@ -58,3 +60,4 @@ do
 		fi
 	done
 done
+EDITOR=echo kvm-find-errors.sh "${@: -1}" > /dev/null 2>&1
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 07/21] rcutorture: Provide rudimentary Makefile
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (5 preceding siblings ...)
  2019-05-30 15:16 ` [PATCH tip/core/rcu 06/21] torture: Make kvm-find-errors.sh and kvm-recheck.sh provide exit status Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:16 ` [PATCH tip/core/rcu 08/21] rcutorture: Exempt tasks RCU from timely draining of grace periods Paul E. McKenney
                   ` (13 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

This commit provides a rudimentary Makefile that runs a 10-minute
rcutorture test on scenario TREE01.  This must be run on a system capable
of spawning virtual machines and with everything installed to permit
building Linux kernels.

Reported-by: Shuah Khan <shuah@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/Makefile | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 tools/testing/selftests/rcutorture/Makefile

diff --git a/tools/testing/selftests/rcutorture/Makefile b/tools/testing/selftests/rcutorture/Makefile
new file mode 100644
index 000000000000..5202dc666206
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+all:
+	( cd ../../../..; tools/testing/selftests/rcutorture/bin/kvm.sh --duration 10 --configs TREE01 )
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 08/21] rcutorture: Exempt tasks RCU from timely draining of grace periods
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (6 preceding siblings ...)
  2019-05-30 15:16 ` [PATCH tip/core/rcu 07/21] rcutorture: Provide rudimentary Makefile Paul E. McKenney
@ 2019-05-30 15:16 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 09/21] rcutorture: Exempt TREE01 from forward-progress testing Paul E. McKenney
                   ` (12 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:16 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

After the end of each stutter pause interval, the rcu_torture_writer()
kthread checks to be sure that all prior callbacks have completed so
that all the test structures have been freed.  This works fine except
for tasks RCU, in which grace periods can take one good long time.
This commit therefore exempts tasks RCU from this check.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 kernel/rcu/rcutorture.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index a16d6abe1715..6a4558532eac 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -299,6 +299,7 @@ struct rcu_torture_ops {
 	int irq_capable;
 	int can_boost;
 	int extendables;
+	int slow_gps;
 	const char *name;
 };
 
@@ -667,6 +668,7 @@ static struct rcu_torture_ops tasks_ops = {
 	.fqs		= NULL,
 	.stats		= NULL,
 	.irq_capable	= 1,
+	.slow_gps	= 1,
 	.name		= "tasks"
 };
 
@@ -1011,7 +1013,8 @@ rcu_torture_writer(void *arg)
 		}
 		rcu_torture_writer_state = RTWS_STUTTER;
 		if (stutter_wait("rcu_torture_writer") &&
-		    !READ_ONCE(rcu_fwd_cb_nodelay))
+		    !READ_ONCE(rcu_fwd_cb_nodelay) &&
+		    !cur_ops->slow_gps)
 			for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)
 				if (list_empty(&rcu_tortures[i].rtort_free) &&
 				    rcu_access_pointer(rcu_torture_current) !=
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 09/21] rcutorture: Exempt TREE01 from forward-progress testing
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (7 preceding siblings ...)
  2019-05-30 15:16 ` [PATCH tip/core/rcu 08/21] rcutorture: Exempt tasks RCU from timely draining of grace periods Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 10/21] rcutorture: Give the scheduler a chance on PREEMPT && NO_HZ_FULL kernels Paul E. McKenney
                   ` (11 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Because TREE01 can end up running more vCPUs that physical CPUs,
hammering these shortchanged CPUs with tight loops containing call_rcu()
invocations seems a bit like overkill.  This commit therefore exempts
TREE01 from rcutorture's forward-progress testing.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
index ea47da95374b..d6da9a61d44a 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
@@ -3,3 +3,4 @@ rcutree.gp_preinit_delay=3
 rcutree.gp_init_delay=3
 rcutree.gp_cleanup_delay=3
 rcu_nocbs=0
+rcutorture.fwd_progress=0
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 10/21] rcutorture: Give the scheduler a chance on PREEMPT && NO_HZ_FULL kernels
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (8 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 09/21] rcutorture: Exempt TREE01 from forward-progress testing Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 11/21] rcutorture: Halt forward-progress checks at end of run Paul E. McKenney
                   ` (10 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

In !PREEMPT kernels, cond_resched() is a no-op.  In NO_HZ_FULL kernels,
in-kernel execution (such as that of rcutorture's kthreads) might extend
indefinitely without the scheduler gaining the aid of a scheduling-clock
interrupt.  This combination can make the interaction of an rcutorture
forward-progress test and a CPU-hotplug stop_machine operation make less
forward progress than one might like.  Additionally, Sebastian Siewior
notes that NO_HZ_FULL kernels have a scheduler check upon return to
userspace execution, which suggests that in-kernel emulation of tight
userspace loops containing system calls doing call_rcu() might also need
explicit checks in the PREEMPT && NO_HZ_FULL case.

This commit therefore introduces a rcu_torture_fwd_prog_cond_resched()
function that explicitly invokes schedule() in such kernels whenever
need_resched() returns true, while retaining use of cond_resched()
for kernels that are either !PREEMPT or !NO_HZ_FULL.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 kernel/rcu/rcutorture.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 6a4558532eac..ef6f6dedf4c4 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1667,6 +1667,17 @@ static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp)
 	spin_unlock_irqrestore(&rcu_fwd_lock, flags);
 }
 
+// Give the scheduler a chance, even on nohz_full CPUs.
+static void rcu_torture_fwd_prog_cond_resched(void)
+{
+	if (IS_ENABLED(CONFIG_PREEMPT) && IS_ENABLED(CONFIG_NO_HZ_FULL)) {
+		if (need_resched())
+			schedule();
+	} else {
+		cond_resched();
+	}
+}
+
 /*
  * Free all callbacks on the rcu_fwd_cb_head list, either because the
  * test is over or because we hit an OOM event.
@@ -1690,7 +1701,7 @@ static unsigned long rcu_torture_fwd_prog_cbfree(void)
 		spin_unlock_irqrestore(&rcu_fwd_lock, flags);
 		kfree(rfcp);
 		freed++;
-		cond_resched();
+		rcu_torture_fwd_prog_cond_resched();
 	}
 	return freed;
 }
@@ -1734,7 +1745,7 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)
 		udelay(10);
 		cur_ops->readunlock(idx);
 		if (!fwd_progress_need_resched || need_resched())
-			cond_resched();
+			rcu_torture_fwd_prog_cond_resched();
 	}
 	(*tested_tries)++;
 	if (!time_before(jiffies, stopat) &&
@@ -1817,7 +1828,7 @@ static void rcu_torture_fwd_prog_cr(void)
 			rfcp->rfc_gps = 0;
 		}
 		cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr);
-		cond_resched();
+		rcu_torture_fwd_prog_cond_resched();
 	}
 	stoppedat = jiffies;
 	n_launders_cb_snap = READ_ONCE(n_launders_cb);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 11/21] rcutorture: Halt forward-progress checks at end of run
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (9 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 10/21] rcutorture: Give the scheduler a chance on PREEMPT && NO_HZ_FULL kernels Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 12/21] rcutorture: Add trivial RCU implementation Paul E. McKenney
                   ` (9 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Once removed, an rcu_torture element can be deferred-freed by a chain
of call_rcu() invocations, with each callback invoking another round of
call_rcu() until either a fixed number of call_rcu() invocations have
been chained or until the test ends.  This means that if the test ends,
some of the rcu_torture elements will be "stranded" partway through the
deferred-free process, which results in false-positive warnings from
rcu_torture_writer() due to lack of forward progress should the test
end just at the end of a stutter interval.

This commit therefore suppresses rcu_torture_writer()'s forward-progress
checks when the test ends in order to avoid these false-positive reports..

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 kernel/rcu/rcutorture.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index ef6f6dedf4c4..a3f5488a319a 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1014,7 +1014,8 @@ rcu_torture_writer(void *arg)
 		rcu_torture_writer_state = RTWS_STUTTER;
 		if (stutter_wait("rcu_torture_writer") &&
 		    !READ_ONCE(rcu_fwd_cb_nodelay) &&
-		    !cur_ops->slow_gps)
+		    !cur_ops->slow_gps &&
+		    !torture_must_stop())
 			for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)
 				if (list_empty(&rcu_tortures[i].rtort_free) &&
 				    rcu_access_pointer(rcu_torture_current) !=
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 12/21] rcutorture: Add trivial RCU implementation
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (10 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 11/21] rcutorture: Halt forward-progress checks at end of run Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 13/21] rcutorture: Tweak kvm options Paul E. McKenney
                   ` (8 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

I have been showing off a trivial RCU implementation for non-preemptive
environments for some time now:

	#define rcu_read_lock()
	#define rcu_read_unlock()
	#define rcu_dereference(p) READ_ONCE(p)
	#define rcu_assign_pointer(p, v) smp_store_release(&(p), (v))
	void synchronize_rcu(void)
	{
	int cpu;
		for_each_online_cpu(cpu)
			sched_setaffinity(current->pid, cpumask_of(cpu));
	}

Trivial or not, as the old saying goes, "if it ain't tested, it don't
work!".  This commit therefore adds a "trivial" flavor to rcutorture
and a corresponding TRIVIAL test scenario.  This variant does not handle
CPU hotplug, which is unconditionally enabled on x86 for post-v5.1-rc3
kernels, which is why the TRIVIAL.boot says "rcutorture.onoff_interval=0".
This commit actually does handle CONFIG_PREEMPT=y kernels, but only
because it turns back the Linux-kernel clock in order to provide these
alternative definitions (or the moral equivalent thereof):

	#define rcu_read_lock() preempt_disable()
	#define rcu_read_unlock() preempt_enable()

In CONFIG_PREEMPT=n kernels without debugging, these are equivalent to
empty macros give or take a compiler barrier.  However, the have been
successfully tested with actual empty macros as well.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Fix symbol issue reported by kbuild test robot <lkp@intel.com>. ]
[ paulmck: Work around sched_setaffinity() issue noted by Andrea Parri. ]
[ paulmck: Add rcutorture.shuffle_interval=0 to TRIVIAL.boot to fix
  interaction with shuffler task noted by Peter Zijlstra. ]
Tested-by: Andrea Parri <andrea.parri@amarulasolutions.com>
---
 kernel/rcu/rcu.h                              |  5 +++
 kernel/rcu/rcutorture.c                       | 45 ++++++++++++++++++-
 kernel/rcu/update.c                           | 13 ++++++
 .../selftests/rcutorture/configs/rcu/TRIVIAL  | 14 ++++++
 .../rcutorture/configs/rcu/TRIVIAL.boot       |  3 ++
 5 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
 create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 390aab20115e..5290b01de534 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -446,6 +446,7 @@ void rcu_request_urgent_qs_task(struct task_struct *t);
 enum rcutorture_type {
 	RCU_FLAVOR,
 	RCU_TASKS_FLAVOR,
+	RCU_TRIVIAL_FLAVOR,
 	SRCU_FLAVOR,
 	INVALID_RCU_FLAVOR
 };
@@ -479,6 +480,10 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
 #endif
 #endif
 
+#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
+long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
+#endif
+
 #ifdef CONFIG_TINY_SRCU
 
 static inline void srcutorture_get_gp_data(enum rcutorture_type test_type,
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index a3f5488a319a..6b803fb2f7ca 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -672,6 +672,47 @@ static struct rcu_torture_ops tasks_ops = {
 	.name		= "tasks"
 };
 
+/*
+ * Definitions for trivial CONFIG_PREEMPT=n-only torture testing.
+ * This implementation does not necessarily work well with CPU hotplug.
+ */
+
+static void synchronize_rcu_trivial(void)
+{
+	int cpu;
+
+	for_each_online_cpu(cpu) {
+		rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu));
+		WARN_ON_ONCE(raw_smp_processor_id() != cpu);
+	}
+}
+
+static int rcu_torture_read_lock_trivial(void) __acquires(RCU)
+{
+	preempt_disable();
+	return 0;
+}
+
+static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU)
+{
+	preempt_enable();
+}
+
+static struct rcu_torture_ops trivial_ops = {
+	.ttype		= RCU_TRIVIAL_FLAVOR,
+	.init		= rcu_sync_torture_init,
+	.readlock	= rcu_torture_read_lock_trivial,
+	.read_delay	= rcu_read_delay,  /* just reuse rcu's version. */
+	.readunlock	= rcu_torture_read_unlock_trivial,
+	.get_gp_seq	= rcu_no_completed,
+	.sync		= synchronize_rcu_trivial,
+	.exp_sync	= synchronize_rcu_trivial,
+	.fqs		= NULL,
+	.stats		= NULL,
+	.irq_capable	= 1,
+	.name		= "trivial"
+};
+
 static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
 {
 	if (!cur_ops->gp_diff)
@@ -1789,6 +1830,8 @@ static void rcu_torture_fwd_prog_cr(void)
 
 	if (READ_ONCE(rcu_fwd_emergency_stop))
 		return; /* Get out of the way quickly, no GP wait! */
+	if (!cur_ops->call)
+		return; /* Can't do call_rcu() fwd prog without ->call. */
 
 	/* Loop continuously posting RCU callbacks. */
 	WRITE_ONCE(rcu_fwd_cb_nodelay, true);
@@ -2265,7 +2308,7 @@ rcu_torture_init(void)
 	int firsterr = 0;
 	static struct rcu_torture_ops *torture_ops[] = {
 		&rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
-		&busted_srcud_ops, &tasks_ops,
+		&busted_srcud_ops, &tasks_ops, &trivial_ops,
 	};
 
 	if (!torture_init_begin(torture_type, verbose))
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index c3bf44ba42e5..61df2bf08563 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -423,6 +423,19 @@ EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read);
 	do { } while (0)
 #endif
 
+#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
+/* Get rcutorture access to sched_setaffinity(). */
+long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
+{
+	int ret;
+
+	ret = sched_setaffinity(pid, in_mask);
+	WARN_ONCE(ret, "%s: sched_setaffinity() returned %d\n", __func__, ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rcutorture_sched_setaffinity);
+#endif
+
 #ifdef CONFIG_RCU_STALL_COMMON
 int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */
 EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress);
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
new file mode 100644
index 000000000000..4d8eb5bfb6f6
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
@@ -0,0 +1,14 @@
+CONFIG_SMP=y
+CONFIG_NR_CPUS=8
+CONFIG_PREEMPT_NONE=y
+CONFIG_PREEMPT_VOLUNTARY=n
+CONFIG_PREEMPT=n
+CONFIG_HZ_PERIODIC=n
+CONFIG_NO_HZ_IDLE=y
+CONFIG_NO_HZ_FULL=n
+CONFIG_HOTPLUG_CPU=n
+CONFIG_SUSPEND=n
+CONFIG_HIBERNATION=n
+CONFIG_DEBUG_LOCK_ALLOC=n
+CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
+CONFIG_RCU_EXPERT=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot
new file mode 100644
index 000000000000..7017f5f5a55f
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot
@@ -0,0 +1,3 @@
+rcutorture.torture_type=trivial
+rcutorture.onoff_interval=0
+rcutorture.shuffle_interval=0
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 13/21] rcutorture: Tweak kvm options
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (11 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 12/21] rcutorture: Add trivial RCU implementation Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 14/21] torture: Capture qemu output Paul E. McKenney
                   ` (7 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Sebastian Andrzej Siewior,
	Paul E . McKenney

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

In one of my rcutorture tests the TSC clocksource got marked unstable
due to a large difference in the TSC value. I'm not sure if the guest
run for a long time with disabled interrupts or if the host was very
busy and didn't schedule the guest for some time.

I took a look on the qemu/KVM options and decided to update the options:

- Use kvm{32|64} as CPU. We could probably use `host' (like ARM does)
  for maximum available features but since we don't run any userland I'm
  not sure if it makes any difference.

- Drop the "noapic" option. There is no history why the APIC was disabled,
  I see no reason for it.  Once old qemu versions fade away, we can add
  "x2apic=on,tsc-deadline=on,hypervisor=on,tsc_adjust=on".

- Additional config options. It ensures that the kernel knowns that it
  runs as a kvm guest and can use virt devices like the kvm-clock as
  clocksource. The kvm-clock was the main motivation here.

- I didn't add a random HW device. It would make the random device ready
  earlier (not it doesn't complete the initialisation at all) but I
  doubt that there is any need for this.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ paulmck: The world is not quite ready for CONFIG_PARAVIRT_SPINLOCKS=y
  and x2apic, so they are omitted for the time being. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/functions.sh | 13 ++++++++++++-
 .../selftests/rcutorture/configs/rcu/CFcommon       |  3 +++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh
index 6bcb8b5b2ff2..c3a49fb4d6f6 100644
--- a/tools/testing/selftests/rcutorture/bin/functions.sh
+++ b/tools/testing/selftests/rcutorture/bin/functions.sh
@@ -172,7 +172,7 @@ identify_qemu_append () {
 	local console=ttyS0
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
-		echo noapic selinux=0 initcall_debug debug
+		echo selinux=0 initcall_debug debug
 		;;
 	qemu-system-aarch64)
 		console=ttyAMA0
@@ -191,8 +191,19 @@ identify_qemu_append () {
 # Output arguments for qemu arguments based on the TORTURE_QEMU_MAC
 # and TORTURE_QEMU_INTERACTIVE environment variables.
 identify_qemu_args () {
+	local KVM_CPU=""
+	case "$1" in
+	qemu-system-x86_64)
+		KVM_CPU=kvm64
+		;;
+	qemu-system-i386)
+		KVM_CPU=kvm32
+		;;
+	esac
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
+		echo -machine q35,accel=kvm
+		echo -cpu ${KVM_CPU}
 		;;
 	qemu-system-aarch64)
 		echo -machine virt,gic-version=host -cpu host
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
index d2d2a86139db..e19a444a0684 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
+++ b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
@@ -1,2 +1,5 @@
 CONFIG_RCU_TORTURE_TEST=y
 CONFIG_PRINTK_TIME=y
+CONFIG_HYPERVISOR_GUEST=y
+CONFIG_PARAVIRT=y
+CONFIG_KVM_GUEST=y
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 14/21] torture: Capture qemu output
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (12 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 13/21] rcutorture: Tweak kvm options Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 15/21] torture: Add function graph-tracing cheat sheet Paul E. McKenney
                   ` (6 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Currently qemu output appears on standard output, but is inaccessible
later on.  This commit therefore captures this output and causes
kvm-recheck.sh to output this output if QEMU gave a non-zero non-137
exit code.  (And exit code of 137 indicates that QEMU was killed, in
which case we want to know about the hang rather than the fact that
QEMU was killed.)

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/kvm-recheck.sh  | 10 +++++++++-
 .../testing/selftests/rcutorture/bin/kvm-test-1-run.sh |  2 +-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
index 2297ddc2d4c5..e5edd5198725 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
@@ -30,8 +30,16 @@ do
 		TORTURE_SUITE="`cat $i/../TORTURE_SUITE`"
 		rm -f $i/console.log.*.diags
 		kvm-recheck-${TORTURE_SUITE}.sh $i
-		if test -f "$i/console.log"
+		if test -f "$i/qemu-retval" && test "`cat $i/qemu-retval`" -ne 0 && test "`cat $i/qemu-retval`" -ne 137
 		then
+			echo QEMU error, output:
+			cat $i/qemu-output
+		elif test -f "$i/console.log"
+		then
+			if test -f "$i/qemu-retval" && test "`cat $i/qemu-retval`" -eq 137
+			then
+				echo QEMU killed
+			fi
 			configcheck.sh $i/.config $i/ConfigFragment
 			if test -r $i/Make.oldconfig.err
 			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 0eb1ec16d78a..003511494fd9 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -165,7 +165,7 @@ then
 fi
 echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log
 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 ) &
+( $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append "$qemu_append $boot_args" > $resdir/qemu-output 2>&1 & 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"
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 15/21] torture: Add function graph-tracing cheat sheet
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (13 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 14/21] torture: Capture qemu output Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 16/21] torture: Run kernel build in source directory Paul E. McKenney
                   ` (5 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/kvm.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 8f1e337b9b54..3b4868906794 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -464,3 +464,5 @@ else
 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
+# Function-graph tracing: ftrace=function_graph ftrace_graph_filter=sched_setaffinity,migration_cpu_stop
+# Also --kconfig "CONFIG_FUNCTION_TRACER=y CONFIG_FUNCTION_GRAPH_TRACER=y"
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 16/21] torture: Run kernel build in source directory
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (14 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 15/21] torture: Add function graph-tracing cheat sheet Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 17/21] torture: Make --cpus override idleness calculations Paul E. McKenney
                   ` (4 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

For historical reasons, rcutorture places its build products in a
tools/testing/selftests/rcutorture/b1 directory using the O= kbuild
command-line argument.  However, doing this requires that the source
directory be pristine: Not just "make clean" pristine, but instead "make
mrproper" (or, equivalently, "make distclean") pristine.  Therefore,
rcutorture executes a "make mrproper" before each build.  Unfortunately,
"make mrproper" has the side effect of removing pretty much everything,
including tags files and cscope databases, which can be inconvenient
to people whose workflow centers around a single source tree.

This commit therefore makes rcutorture do the build directly in the
source directory, removing the need for "make mrproper".  This works
because all needed build products are moved to their proper place in the
"res" directory immediately after the build completes, so that multiple
rcutorture kernels can still run concurrently.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 .../selftests/rcutorture/bin/configinit.sh    | 36 +++++--------------
 .../selftests/rcutorture/bin/kvm-build.sh     |  9 +++--
 .../rcutorture/bin/kvm-test-1-run.sh          | 21 +++++------
 tools/testing/selftests/rcutorture/bin/kvm.sh |  3 +-
 4 files changed, 22 insertions(+), 47 deletions(-)

diff --git a/tools/testing/selftests/rcutorture/bin/configinit.sh b/tools/testing/selftests/rcutorture/bin/configinit.sh
index 40359486b3a8..bbeae6f67c36 100755
--- a/tools/testing/selftests/rcutorture/bin/configinit.sh
+++ b/tools/testing/selftests/rcutorture/bin/configinit.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0+
 #
-# Usage: configinit.sh config-spec-file build-output-dir results-dir
+# Usage: configinit.sh config-spec-file results-dir
 #
 # Create a .config file from the spec file.  Run from the kernel source tree.
 # Exits with 0 if all went well, with 1 if all went well but the config
@@ -11,10 +11,6 @@
 # desired settings, for example, "CONFIG_NO_HZ=y".  For best results,
 # this should be a full pathname.
 #
-# The second argument is a optional path to a build output directory,
-# for example, "O=/tmp/foo".  If this argument is omitted, the .config
-# file will be generated directly in the current directory.
-#
 # Copyright (C) IBM Corporation, 2013
 #
 # Authors: Paul E. McKenney <paulmck@linux.ibm.com>
@@ -26,34 +22,20 @@ mkdir $T
 # Capture config spec file.
 
 c=$1
-buildloc=$2
-resdir=$3
-builddir=
-if echo $buildloc | grep -q '^O='
-then
-	builddir=`echo $buildloc | sed -e 's/^O=//'`
-	if test ! -d $builddir
-	then
-		mkdir $builddir
-	fi
-else
-	echo Bad build directory: \"$buildloc\"
-	exit 2
-fi
+resdir=$2
 
 sed -e 's/^\(CONFIG[0-9A-Z_]*\)=.*$/grep -v "^# \1" |/' < $c > $T/u.sh
 sed -e 's/^\(CONFIG[0-9A-Z_]*=\).*$/grep -v \1 |/' < $c >> $T/u.sh
 grep '^grep' < $T/u.sh > $T/upd.sh
 echo "cat - $c" >> $T/upd.sh
-make mrproper
-make $buildloc distclean > $resdir/Make.distclean 2>&1
-make $buildloc $TORTURE_DEFCONFIG > $resdir/Make.defconfig.out 2>&1
-mv $builddir/.config $builddir/.config.sav
-sh $T/upd.sh < $builddir/.config.sav > $builddir/.config
-cp $builddir/.config $builddir/.config.new
-yes '' | make $buildloc oldconfig > $resdir/Make.oldconfig.out 2> $resdir/Make.oldconfig.err
+make clean > $resdir/Make.clean 2>&1
+make $TORTURE_DEFCONFIG > $resdir/Make.defconfig.out 2>&1
+mv .config .config.sav
+sh $T/upd.sh < .config.sav > .config
+cp .config .config.new
+yes '' | make oldconfig > $resdir/Make.oldconfig.out 2> $resdir/Make.oldconfig.err
 
 # verify new config matches specification.
-configcheck.sh $builddir/.config $c
+configcheck.sh .config $c
 
 exit 0
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-build.sh b/tools/testing/selftests/rcutorture/bin/kvm-build.sh
index c27a0bbb9c02..18d6518504ee 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-build.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-build.sh
@@ -3,7 +3,7 @@
 #
 # Build a kvm-ready Linux kernel from the tree in the current directory.
 #
-# Usage: kvm-build.sh config-template build-dir resdir
+# Usage: kvm-build.sh config-template resdir
 #
 # Copyright (C) IBM Corporation, 2011
 #
@@ -15,8 +15,7 @@ then
 	echo "kvm-build.sh :$config_template: Not a readable file"
 	exit 1
 fi
-builddir=${2}
-resdir=${3}
+resdir=${2}
 
 T=${TMPDIR-/tmp}/test-linux.sh.$$
 trap 'rm -rf $T' 0
@@ -29,14 +28,14 @@ CONFIG_VIRTIO_PCI=y
 CONFIG_VIRTIO_CONSOLE=y
 ___EOF___
 
-configinit.sh $T/config O=$builddir $resdir
+configinit.sh $T/config $resdir
 retval=$?
 if test $retval -gt 1
 then
 	exit 2
 fi
 ncpus=`cpus2use.sh`
-make O=$builddir -j$ncpus $TORTURE_KMAKE_ARG > $resdir/Make.out 2>&1
+make -j$ncpus $TORTURE_KMAKE_ARG > $resdir/Make.out 2>&1
 retval=$?
 if test $retval -ne 0 || grep "rcu[^/]*": < $resdir/Make.out | egrep -q "Stop|Error|error:|warning:" || egrep -q "Stop|Error|error:" < $resdir/Make.out
 then
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
index 003511494fd9..27b7b5693ede 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -36,11 +36,6 @@ config_template=${1}
 config_dir=`echo $config_template | sed -e 's,/[^/]*$,,'`
 title=`echo $config_template | sed -e 's/^.*\///'`
 builddir=${2}
-if test -z "$builddir" -o ! -d "$builddir" -o ! -w "$builddir"
-then
-	echo "kvm-test-1-run.sh :$builddir: Not a writable directory, cannot build into it"
-	exit 1
-fi
 resdir=${3}
 if test -z "$resdir" -o ! -d "$resdir" -o ! -w "$resdir"
 then
@@ -85,18 +80,18 @@ then
 	ln -s $base_resdir/.config $resdir  # for kvm-recheck.sh
 	# Arch-independent indicator
 	touch $resdir/builtkernel
-elif kvm-build.sh $T/Kc2 $builddir $resdir
+elif kvm-build.sh $T/Kc2 $resdir
 then
 	# Had to build a kernel for this test.
-	QEMU="`identify_qemu $builddir/vmlinux`"
+	QEMU="`identify_qemu vmlinux`"
 	BOOT_IMAGE="`identify_boot_image $QEMU`"
-	cp $builddir/vmlinux $resdir
-	cp $builddir/.config $resdir
-	cp $builddir/Module.symvers $resdir > /dev/null || :
-	cp $builddir/System.map $resdir > /dev/null || :
+	cp vmlinux $resdir
+	cp .config $resdir
+	cp Module.symvers $resdir > /dev/null || :
+	cp System.map $resdir > /dev/null || :
 	if test -n "$BOOT_IMAGE"
 	then
-		cp $builddir/$BOOT_IMAGE $resdir
+		cp $BOOT_IMAGE $resdir
 		KERNEL=$resdir/${BOOT_IMAGE##*/}
 		# Arch-independent indicator
 		touch $resdir/builtkernel
@@ -107,7 +102,7 @@ then
 	parse-build.sh $resdir/Make.out $title
 else
 	# Build failed.
-	cp $builddir/.config $resdir || :
+	cp .config $resdir || :
 	echo Build failed, not running KVM, see $resdir.
 	if test -f $builddir.wait
 	then
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 3b4868906794..8c43eb43409b 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -342,7 +342,7 @@ function dump(first, pastlast, batchnum)
 	print "needqemurun="
 	jn=1
 	for (j = first; j < pastlast; j++) {
-		builddir=KVM "/b1"
+		builddir=KVM "/b" j - first + 1
 		cpusr[jn] = cpus[j];
 		if (cfrep[cf[j]] == "") {
 			cfr[jn] = cf[j];
@@ -358,7 +358,6 @@ function dump(first, pastlast, batchnum)
 		print "echo ", cfr[jn], cpusr[jn] ovf ": Starting build. `date` | tee -a " rd "log";
 		print "rm -f " builddir ".*";
 		print "touch " builddir ".wait";
-		print "mkdir " builddir " > /dev/null 2>&1 || :";
 		print "mkdir " rd cfr[jn] " || :";
 		print "kvm-test-1-run.sh " CONFIGDIR cf[j], builddir, rd cfr[jn], dur " \"" TORTURE_QEMU_ARG "\" \"" TORTURE_BOOTARGS "\" > " rd cfr[jn]  "/kvm-test-1-run.sh.out 2>&1 &"
 		print "echo ", cfr[jn], cpusr[jn] ovf ": Waiting for build to complete. `date` | tee -a " rd "log";
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 17/21] torture: Make --cpus override idleness calculations
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (15 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 16/21] torture: Run kernel build in source directory Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 18/21] torture: Add --trust-make to suppress "make clean" Paul E. McKenney
                   ` (3 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Currently, rcutorture will use relatively few CPUs to build the kernel
on a busy system, which is often as it should be.  However, if the user
has used the --cpus argument to dedicate a specified number of CPUs to
this torture test, it would be good if the kernel build also made use
of them.  This commit therefore changes the cpus2use.sh script to use
--cpus when specified and to do the idleness calculations otherwise.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/cpus2use.sh | 5 +++++
 tools/testing/selftests/rcutorture/bin/kvm.sh      | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/tools/testing/selftests/rcutorture/bin/cpus2use.sh b/tools/testing/selftests/rcutorture/bin/cpus2use.sh
index ff7102212703..4e9485590c10 100755
--- a/tools/testing/selftests/rcutorture/bin/cpus2use.sh
+++ b/tools/testing/selftests/rcutorture/bin/cpus2use.sh
@@ -9,6 +9,11 @@
 #
 # Authors: Paul E. McKenney <paulmck@linux.ibm.com>
 
+if test -n "$TORTURE_ALLOTED_CPUS"
+then
+	echo $TORTURE_ALLOTED_CPUS
+	exit 0
+fi
 ncpus=`grep '^processor' /proc/cpuinfo | wc -l`
 idlecpus=`mpstat | tail -1 | \
 	awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'`
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 8c43eb43409b..ea6289a335f2 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -24,6 +24,7 @@ dur=$((30*60))
 dryrun=""
 KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
 PATH=${KVM}/bin:$PATH; export PATH
+TORTURE_ALLOTED_CPUS=""
 TORTURE_DEFCONFIG=defconfig
 TORTURE_BOOT_IMAGE=""
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
@@ -89,6 +90,7 @@ do
 	--cpus)
 		checkarg --cpus "(number)" "$#" "$2" '^[0-9]*$' '^--'
 		cpus=$2
+		TORTURE_ALLOTED_CPUS="$2"
 		shift
 		;;
 	--datestamp)
@@ -285,6 +287,7 @@ cat << ___EOF___ > $T/script
 CONFIGFRAG="$CONFIGFRAG"; export CONFIGFRAG
 KVM="$KVM"; export KVM
 PATH="$PATH"; export PATH
+TORTURE_ALLOTED_CPUS="$TORTURE_ALLOTED_CPUS"; export TORTURE_ALLOTED_CPUS
 TORTURE_BOOT_IMAGE="$TORTURE_BOOT_IMAGE"; export TORTURE_BOOT_IMAGE
 TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY
 TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 18/21] torture: Add --trust-make to suppress "make clean"
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (16 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 17/21] torture: Make --cpus override idleness calculations Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 19/21] rcutorture: Dump trace buffer for callback pipe drain failures Paul E. McKenney
                   ` (2 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

The current rcutorture scripts unconditionally do "make clean", which is
a good way of getting the needed testing done despite any imperfections in
Makefile dependency tracking.  However, this can be a bit irritating when
repeatedly running a single scenario after small changes, for example,
when debugging a problem that affects only a single scenario.  This commit
therefore adds a --trust-make argument that suppresses the "make clean".

Even when using ccache, this speeds up kernel builds by up to almost an
order of magnitude on my laptop.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/configinit.sh  | 5 ++++-
 tools/testing/selftests/rcutorture/bin/kvm.sh         | 6 ++++++
 tools/testing/selftests/rcutorture/bin/parse-build.sh | 2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rcutorture/bin/configinit.sh b/tools/testing/selftests/rcutorture/bin/configinit.sh
index bbeae6f67c36..93e80a42249a 100755
--- a/tools/testing/selftests/rcutorture/bin/configinit.sh
+++ b/tools/testing/selftests/rcutorture/bin/configinit.sh
@@ -28,7 +28,10 @@ sed -e 's/^\(CONFIG[0-9A-Z_]*\)=.*$/grep -v "^# \1" |/' < $c > $T/u.sh
 sed -e 's/^\(CONFIG[0-9A-Z_]*=\).*$/grep -v \1 |/' < $c >> $T/u.sh
 grep '^grep' < $T/u.sh > $T/upd.sh
 echo "cat - $c" >> $T/upd.sh
-make clean > $resdir/Make.clean 2>&1
+if test -z "$TORTURE_TRUST_MAKE"
+then
+	make clean > $resdir/Make.clean 2>&1
+fi
 make $TORTURE_DEFCONFIG > $resdir/Make.defconfig.out 2>&1
 mv .config .config.sav
 sh $T/upd.sh < .config.sav > .config
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index ea6289a335f2..72518580df23 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -33,6 +33,7 @@ TORTURE_KMAKE_ARG=""
 TORTURE_QEMU_MEM=512
 TORTURE_SHUTDOWN_GRACE=180
 TORTURE_SUITE=rcu
+TORTURE_TRUST_MAKE=""
 resdir=""
 configs=""
 cpus=0
@@ -63,6 +64,7 @@ usage () {
 	echo "       --qemu-cmd qemu-system-..."
 	echo "       --results absolute-pathname"
 	echo "       --torture rcu"
+	echo "       --trust-make"
 	exit 1
 }
 
@@ -175,6 +177,9 @@ do
 			jitter=0
 		fi
 		;;
+	--trust-make)
+		TORTURE_TRUST_MAKE="y"
+		;;
 	*)
 		echo Unknown argument $1
 		usage
@@ -300,6 +305,7 @@ TORTURE_QEMU_MAC="$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="$TORTURE_SUITE"; export TORTURE_SUITE
+TORTURE_TRUST_MAKE="$TORTURE_TRUST_MAKE"; export TORTURE_TRUST_MAKE
 if ! test -e $resdir
 then
 	mkdir -p "$resdir" || :
diff --git a/tools/testing/selftests/rcutorture/bin/parse-build.sh b/tools/testing/selftests/rcutorture/bin/parse-build.sh
index 0701b3bf6ade..09155c15ea65 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-build.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-build.sh
@@ -21,7 +21,7 @@ mkdir $T
 
 . functions.sh
 
-if grep -q CC < $F
+if grep -q CC < $F || test -n "$TORTURE_TRUST_MAKE"
 then
 	:
 else
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 19/21] rcutorture: Dump trace buffer for callback pipe drain failures
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (17 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 18/21] torture: Add --trust-make to suppress "make clean" Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 20/21] torture: Suppress propagating trace_printk() warning Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 21/21] rcutorture: Upper case solves the case of the vanishing NULL pointer Paul E. McKenney
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 kernel/rcu/rcutorture.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 6b803fb2f7ca..89be0f492f78 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1060,8 +1060,10 @@ rcu_torture_writer(void *arg)
 			for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)
 				if (list_empty(&rcu_tortures[i].rtort_free) &&
 				    rcu_access_pointer(rcu_torture_current) !=
-				    &rcu_tortures[i])
+				    &rcu_tortures[i]) {
+					rcu_ftrace_dump(DUMP_ALL);
 					WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
+				}
 	} while (!torture_must_stop());
 	/* Reset expediting back to unexpedited. */
 	if (expediting > 0)
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 20/21] torture: Suppress propagating trace_printk() warning
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (18 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 19/21] rcutorture: Dump trace buffer for callback pipe drain failures Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  2019-05-30 15:17 ` [PATCH tip/core/rcu 21/21] rcutorture: Upper case solves the case of the vanishing NULL pointer Paul E. McKenney
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

When trace_printk() is used, a message including "BUG" is printed to
the console, which fools the rcutorture scripting into believing that
the corresponding test scenario failed.  This commit therefore filters
out this particular instance of "BUG", thus avoiding the false-positive
test-failure report.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/parse-console.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/rcutorture/bin/parse-console.sh b/tools/testing/selftests/rcutorture/bin/parse-console.sh
index 4508373a922f..4bf62d7b1cbc 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-console.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-console.sh
@@ -106,6 +106,7 @@ fi | tee -a $file.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 'This means that this is a DEBUG kernel and it is' |
 grep -v 'Warning: unable to open an initial console' > $T.diags
 if test -s $T.diags
 then
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
* [PATCH tip/core/rcu 21/21] rcutorture: Upper case solves the case of the vanishing NULL pointer
  2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
                   ` (19 preceding siblings ...)
  2019-05-30 15:17 ` [PATCH tip/core/rcu 20/21] torture: Suppress propagating trace_printk() warning Paul E. McKenney
@ 2019-05-30 15:17 ` Paul E. McKenney
  20 siblings, 0 replies; 22+ messages in thread
From: Paul E. McKenney @ 2019-05-30 15:17 UTC (permalink / raw)
  To: rcu
  Cc: linux-kernel, mingo, jiangshanlai, dipankar, akpm,
	mathieu.desnoyers, josh, tglx, peterz, rostedt, dhowells,
	edumazet, fweisbec, oleg, joel, Paul E. McKenney

Various security techniques can obfuscate pointer printouts on the
console.  Unfortunately, rcutorture relies on either "null" or all zeroes
to identify the last few statistics printouts at the end of the test.
These need to be identified because failing to do so will results in
false-positive complaints about grace-period hangs.

This commit therefore prints the "ver:" in capitals ("VER:") when
the RCU-protected pointer has been set to NULL, which causes rcutorture's
parse-console.sh script to correctly ignore these lines.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 kernel/rcu/rcutorture.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 89be0f492f78..fce4e7e6f502 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1408,8 +1408,9 @@ rcu_torture_stats_print(void)
 	}
 
 	pr_alert("%s%s ", torture_type, TORTURE_FLAG);
-	pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
+	pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
 		rcu_torture_current,
+		rcu_torture_current ? "ver" : "VER",
 		rcu_torture_current_version,
 		list_empty(&rcu_torture_freelist),
 		atomic_read(&n_rcu_torture_alloc),
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 22+ messages in thread
end of thread, other threads:[~2019-05-30 15:20 UTC | newest]

Thread overview: 22+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-30 15:16 [PATCH tip/core/rcu 0/21] Torture-test updates for v5.3 Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 01/21] rcutorture: Select from only online CPUs Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 02/21] rcutorture: Add cpu0 to the set of CPUs to add jitter Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 03/21] rcutorture: Add cond_resched() to forward-progress free-up loop Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 04/21] rcutorture: Fix stutter_wait() return value and freelist checks Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 05/21] torture: Allow inter-stutter interval to be specified Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 06/21] torture: Make kvm-find-errors.sh and kvm-recheck.sh provide exit status Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 07/21] rcutorture: Provide rudimentary Makefile Paul E. McKenney
2019-05-30 15:16 ` [PATCH tip/core/rcu 08/21] rcutorture: Exempt tasks RCU from timely draining of grace periods Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 09/21] rcutorture: Exempt TREE01 from forward-progress testing Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 10/21] rcutorture: Give the scheduler a chance on PREEMPT && NO_HZ_FULL kernels Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 11/21] rcutorture: Halt forward-progress checks at end of run Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 12/21] rcutorture: Add trivial RCU implementation Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 13/21] rcutorture: Tweak kvm options Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 14/21] torture: Capture qemu output Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 15/21] torture: Add function graph-tracing cheat sheet Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 16/21] torture: Run kernel build in source directory Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 17/21] torture: Make --cpus override idleness calculations Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 18/21] torture: Add --trust-make to suppress "make clean" Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 19/21] rcutorture: Dump trace buffer for callback pipe drain failures Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 20/21] torture: Suppress propagating trace_printk() warning Paul E. McKenney
2019-05-30 15:17 ` [PATCH tip/core/rcu 21/21] rcutorture: Upper case solves the case of the vanishing NULL pointer Paul E. McKenney

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