* [PATCH tip/core/rcu 1/3] rcutorture: Add interrupt-disable capability to stall-warning tests
2017-10-04 21:56 [PATCH tip/core/rcu 0/3] Torture-test update for v4.15 Paul E. McKenney
@ 2017-10-04 21:56 ` Paul E. McKenney
2017-10-04 21:56 ` [PATCH tip/core/rcu 2/3] rcutorture: Dump writer stack if stalled Paul E. McKenney
2017-10-04 21:56 ` [PATCH tip/core/rcu 3/3] torture: Provide TMPDIR environment variable to specify tmpdir Paul E. McKenney
2 siblings, 0 replies; 4+ messages in thread
From: Paul E. McKenney @ 2017-10-04 21:56 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg,
Paul E. McKenney
When rcutorture sees the rcutorture.stall_cpu kernel boot parameter,
it loops with preemption disabled, which does in fact normally
generate an RCU CPU stall warning message. However, there are test
scenarios that need the stalling CPU to have interrupts disabled.
This commit therefore adds an rcutorture.stall_cpu_irqsoff kernel
boot parameter that causes the stalling CPU to disable interrupts.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
Documentation/admin-guide/kernel-parameters.txt | 3 +++
kernel/rcu/rcutorture.c | 18 +++++++++++++-----
2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 05496622b4ef..bc94c47085a5 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3539,6 +3539,9 @@
rcutorture.stall_cpu_holdoff= [KNL]
Time to wait (s) after boot before inducing stall.
+ rcutorture.stall_cpu_irqsoff= [KNL]
+ Disable interrupts while stalling if set.
+
rcutorture.stat_interval= [KNL]
Time (s) between statistics printk()s.
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 45f2ffbc1e78..0273bc0a8586 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -89,6 +89,7 @@ torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
torture_param(int, stall_cpu_holdoff, 10,
"Time to wait before starting stall (s).");
+torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling.");
torture_param(int, stat_interval, 60,
"Number of seconds between stats printk()s");
torture_param(int, stutter, 5, "Number of seconds to run/halt test");
@@ -1357,7 +1358,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
"fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
"test_boost=%d/%d test_boost_interval=%d "
"test_boost_duration=%d shutdown_secs=%d "
- "stall_cpu=%d stall_cpu_holdoff=%d "
+ "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
"n_barrier_cbs=%d "
"onoff_interval=%d onoff_holdoff=%d\n",
torture_type, tag, nrealreaders, nfakewriters,
@@ -1365,7 +1366,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
test_boost, cur_ops->can_boost,
test_boost_interval, test_boost_duration, shutdown_secs,
- stall_cpu, stall_cpu_holdoff,
+ stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff,
n_barrier_cbs,
onoff_interval, onoff_holdoff);
}
@@ -1430,12 +1431,19 @@ static int rcu_torture_stall(void *args)
if (!kthread_should_stop()) {
stop_at = get_seconds() + stall_cpu;
/* RCU CPU stall is expected behavior in following code. */
- pr_alert("rcu_torture_stall start.\n");
rcu_read_lock();
- preempt_disable();
+ if (stall_cpu_irqsoff)
+ local_irq_disable();
+ else
+ preempt_disable();
+ pr_alert("rcu_torture_stall start on CPU %d.\n",
+ smp_processor_id());
while (ULONG_CMP_LT(get_seconds(), stop_at))
continue; /* Induce RCU CPU stall warning. */
- preempt_enable();
+ if (stall_cpu_irqsoff)
+ local_irq_enable();
+ else
+ preempt_enable();
rcu_read_unlock();
pr_alert("rcu_torture_stall end.\n");
}
--
2.5.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH tip/core/rcu 2/3] rcutorture: Dump writer stack if stalled
2017-10-04 21:56 [PATCH tip/core/rcu 0/3] Torture-test update for v4.15 Paul E. McKenney
2017-10-04 21:56 ` [PATCH tip/core/rcu 1/3] rcutorture: Add interrupt-disable capability to stall-warning tests Paul E. McKenney
@ 2017-10-04 21:56 ` Paul E. McKenney
2017-10-04 21:56 ` [PATCH tip/core/rcu 3/3] torture: Provide TMPDIR environment variable to specify tmpdir Paul E. McKenney
2 siblings, 0 replies; 4+ messages in thread
From: Paul E. McKenney @ 2017-10-04 21:56 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg,
Paul E. McKenney
Right now, rcutorture warns if an rcu_torture_writer() kthread stalls,
but this warning is not always all that helpful. This commit therefore
makes the first such warning include a stack dump.
This in turn requires that sched_show_task() be exported to GPL modules,
so this commit makes that change as well.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/rcutorture.c | 6 ++++++
kernel/sched/core.c | 1 +
2 files changed, 7 insertions(+)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 0273bc0a8586..362eb2f78b3c 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -51,6 +51,7 @@
#include <asm/byteorder.h>
#include <linux/torture.h>
#include <linux/vmalloc.h>
+#include <linux/sched/debug.h>
#include "rcu.h"
@@ -1240,6 +1241,7 @@ rcu_torture_stats_print(void)
long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
static unsigned long rtcv_snap = ULONG_MAX;
+ static bool splatted;
struct task_struct *wtp;
for_each_possible_cpu(cpu) {
@@ -1325,6 +1327,10 @@ rcu_torture_stats_print(void)
gpnum, completed, flags,
wtp == NULL ? ~0UL : wtp->state,
wtp == NULL ? -1 : (int)task_cpu(wtp));
+ if (!splatted && wtp) {
+ sched_show_task(wtp);
+ splatted = true;
+ }
show_rcu_gp_kthreads();
rcu_ftrace_dump(DUMP_ALL);
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d17c5da523a0..7ae0151dcc1d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5165,6 +5165,7 @@ void sched_show_task(struct task_struct *p)
show_stack(p, NULL);
put_task_stack(p);
}
+EXPORT_SYMBOL_GPL(sched_show_task);
static inline bool
state_filter_match(unsigned long state_filter, struct task_struct *p)
--
2.5.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH tip/core/rcu 3/3] torture: Provide TMPDIR environment variable to specify tmpdir
2017-10-04 21:56 [PATCH tip/core/rcu 0/3] Torture-test update for v4.15 Paul E. McKenney
2017-10-04 21:56 ` [PATCH tip/core/rcu 1/3] rcutorture: Add interrupt-disable capability to stall-warning tests Paul E. McKenney
2017-10-04 21:56 ` [PATCH tip/core/rcu 2/3] rcutorture: Dump writer stack if stalled Paul E. McKenney
@ 2017-10-04 21:56 ` Paul E. McKenney
2 siblings, 0 replies; 4+ messages in thread
From: Paul E. McKenney @ 2017-10-04 21:56 UTC (permalink / raw)
To: linux-kernel
Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg,
Paul E. McKenney
Both rcutorture and locktorture currently place temporary files in /tmp,
in keeping with decades-long tradition. However, sometimes it is useful
to specify an alternative temporary directory, for example, for space
or performance reasons. This commit therefore causes the torture-test
scripting to use the path specified in the TMPDIR environment variable,
or to fall back to traditional /tmp if this variable is not set.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
tools/testing/selftests/rcutorture/bin/config_override.sh | 2 +-
tools/testing/selftests/rcutorture/bin/configcheck.sh | 2 +-
tools/testing/selftests/rcutorture/bin/configinit.sh | 2 +-
tools/testing/selftests/rcutorture/bin/kvm-build.sh | 2 +-
tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh | 2 +-
tools/testing/selftests/rcutorture/bin/kvm.sh | 4 ++--
tools/testing/selftests/rcutorture/bin/parse-build.sh | 2 +-
tools/testing/selftests/rcutorture/bin/parse-torture.sh | 2 +-
8 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/rcutorture/bin/config_override.sh b/tools/testing/selftests/rcutorture/bin/config_override.sh
index 49fa51726ce3..ef7fcbac3d42 100755
--- a/tools/testing/selftests/rcutorture/bin/config_override.sh
+++ b/tools/testing/selftests/rcutorture/bin/config_override.sh
@@ -42,7 +42,7 @@ else
exit 1
fi
-T=/tmp/config_override.sh.$$
+T=${TMPDIR-/tmp}/config_override.sh.$$
trap 'rm -rf $T' 0
mkdir $T
diff --git a/tools/testing/selftests/rcutorture/bin/configcheck.sh b/tools/testing/selftests/rcutorture/bin/configcheck.sh
index 70fca318a82b..197deece7c7c 100755
--- a/tools/testing/selftests/rcutorture/bin/configcheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/configcheck.sh
@@ -19,7 +19,7 @@
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-T=/tmp/abat-chk-config.sh.$$
+T=${TMPDIR-/tmp}/abat-chk-config.sh.$$
trap 'rm -rf $T' 0
mkdir $T
diff --git a/tools/testing/selftests/rcutorture/bin/configinit.sh b/tools/testing/selftests/rcutorture/bin/configinit.sh
index 3f81a1095206..51f66a7ce876 100755
--- a/tools/testing/selftests/rcutorture/bin/configinit.sh
+++ b/tools/testing/selftests/rcutorture/bin/configinit.sh
@@ -32,7 +32,7 @@
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-T=/tmp/configinit.sh.$$
+T=${TMPDIR-/tmp}/configinit.sh.$$
trap 'rm -rf $T' 0
mkdir $T
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-build.sh b/tools/testing/selftests/rcutorture/bin/kvm-build.sh
index 46752c164676..fb66d0173638 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-build.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-build.sh
@@ -35,7 +35,7 @@ then
exit 1
fi
-T=/tmp/test-linux.sh.$$
+T=${TMPDIR-/tmp}/test-linux.sh.$$
trap 'rm -rf $T' 0
mkdir $T
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 0af36a721b9c..ab14b97c942c 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -38,7 +38,7 @@
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-T=/tmp/kvm-test-1-run.sh.$$
+T=${TMPDIR-/tmp}/kvm-test-1-run.sh.$$
trap 'rm -rf $T' 0
mkdir $T
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index b55895fb10ed..ccd49e958fd2 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -30,7 +30,7 @@
scriptname=$0
args="$*"
-T=/tmp/kvm.sh.$$
+T=${TMPDIR-/tmp}/kvm.sh.$$
trap 'rm -rf $T' 0
mkdir $T
@@ -222,7 +222,7 @@ do
exit 1
fi
done
-sort -k2nr $T/cfgcpu > $T/cfgcpu.sort
+sort -k2nr $T/cfgcpu -T="$T" > $T/cfgcpu.sort
# Use a greedy bin-packing algorithm, sorting the list accordingly.
awk < $T/cfgcpu.sort > $T/cfgcpu.pack -v ncpus=$cpus '
diff --git a/tools/testing/selftests/rcutorture/bin/parse-build.sh b/tools/testing/selftests/rcutorture/bin/parse-build.sh
index a6b57622c2e5..24fe5f822b28 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-build.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-build.sh
@@ -28,7 +28,7 @@
F=$1
title=$2
-T=/tmp/parse-build.sh.$$
+T=${TMPDIR-/tmp}/parse-build.sh.$$
trap 'rm -rf $T' 0
mkdir $T
diff --git a/tools/testing/selftests/rcutorture/bin/parse-torture.sh b/tools/testing/selftests/rcutorture/bin/parse-torture.sh
index e3c5f0705696..f12c38909b00 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-torture.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-torture.sh
@@ -27,7 +27,7 @@
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-T=/tmp/parse-torture.sh.$$
+T=${TMPDIR-/tmp}/parse-torture.sh.$$
file="$1"
title="$2"
--
2.5.2
^ permalink raw reply related [flat|nested] 4+ messages in thread