In order to extend locktorture to support lock nesting, add
nested_lock() and nested_unlock() hooks to the torture ops.
These take a 32bit lockset mask which is generated at random,
so some number of locks will be taken before the main lock is
taken and released afterwards.
Additionally, add nested_locks module parameter to allow
specifying the number of nested locks to be used.
This has been helpful to uncover issues in the proxy-exec
series development.
This was inspired by locktorture extensions originally implemented
by Connor O'Brien, for stress testing the proxy-execution series:
https://lore.kernel.org/lkml/[email protected]/
Cc: Davidlohr Bueso <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: [email protected]
Reviewed-by: Davidlohr Bueso <[email protected]>
Co-developed-by: Connor O'Brien <[email protected]>
Signed-off-by: Connor O'Brien <[email protected]>
Signed-off-by: John Stultz <[email protected]>
---
v3:
* Minor commit message tweaks and naming changes
suggested by Davidlohr Bueso
v4:
* Add co-developed tag
---
kernel/locking/locktorture.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 9c2fb613a55d..6fe046594868 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -48,6 +48,9 @@ torture_param(int, stat_interval, 60,
torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
torture_param(int, verbose, 1,
"Enable verbose debugging printk()s");
+torture_param(int, nested_locks, 0, "Number of nested locks (max = 8)");
+/* Going much higher trips "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!" errors */
+#define MAX_NESTED_LOCKS 8
static char *torture_type = "spin_lock";
module_param(torture_type, charp, 0444);
@@ -76,10 +79,12 @@ static void lock_torture_cleanup(void);
struct lock_torture_ops {
void (*init)(void);
void (*exit)(void);
+ int (*nested_lock)(int tid, u32 lockset);
int (*writelock)(int tid);
void (*write_delay)(struct torture_random_state *trsp);
void (*task_boost)(struct torture_random_state *trsp);
void (*writeunlock)(int tid);
+ void (*nested_unlock)(int tid, u32 lockset);
int (*readlock)(int tid);
void (*read_delay)(struct torture_random_state *trsp);
void (*readunlock)(int tid);
@@ -669,6 +674,7 @@ static int lock_torture_writer(void *arg)
struct lock_stress_stats *lwsp = arg;
int tid = lwsp - cxt.lwsa;
DEFINE_TORTURE_RANDOM(rand);
+ u32 lockset_mask;
VERBOSE_TOROUT_STRING("lock_torture_writer task started");
set_user_nice(current, MAX_NICE);
@@ -677,7 +683,10 @@ static int lock_torture_writer(void *arg)
if ((torture_random(&rand) & 0xfffff) == 0)
schedule_timeout_uninterruptible(1);
+ lockset_mask = torture_random(&rand);
cxt.cur_ops->task_boost(&rand);
+ if (cxt.cur_ops->nested_lock)
+ cxt.cur_ops->nested_lock(tid, lockset_mask);
cxt.cur_ops->writelock(tid);
if (WARN_ON_ONCE(lock_is_write_held))
lwsp->n_lock_fail++;
@@ -690,6 +699,8 @@ static int lock_torture_writer(void *arg)
lock_is_write_held = false;
WRITE_ONCE(last_lock_release, jiffies);
cxt.cur_ops->writeunlock(tid);
+ if (cxt.cur_ops->nested_unlock)
+ cxt.cur_ops->nested_unlock(tid, lockset_mask);
stutter_wait("lock_torture_writer");
} while (!torture_must_stop());
@@ -830,11 +841,11 @@ lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
const char *tag)
{
pr_alert("%s" TORTURE_FLAG
- "--- %s%s: nwriters_stress=%d nreaders_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
+ "--- %s%s: nwriters_stress=%d nreaders_stress=%d nested_locks=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
torture_type, tag, cxt.debug_lock ? " [debug]": "",
- cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval,
- verbose, shuffle_interval, stutter, shutdown_secs,
- onoff_interval, onoff_holdoff);
+ cxt.nrealwriters_stress, cxt.nrealreaders_stress,
+ nested_locks, stat_interval, verbose, shuffle_interval,
+ stutter, shutdown_secs, onoff_interval, onoff_holdoff);
}
static void lock_torture_cleanup(void)
@@ -1053,6 +1064,10 @@ static int __init lock_torture_init(void)
}
}
+ /* cap nested_locks to MAX_NESTED_LOCKS */
+ if (nested_locks > MAX_NESTED_LOCKS)
+ nested_locks = MAX_NESTED_LOCKS;
+
if (cxt.cur_ops->readlock) {
reader_tasks = kcalloc(cxt.nrealreaders_stress,
sizeof(reader_tasks[0]),
--
2.39.2.637.g21b0678d19-goog
This patch adds randomized nested locking to the mutex torture
tests, as well as new LOCK08 config files for testing mutexes
with nested locking
Cc: Davidlohr Bueso <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: [email protected]
Reviewed-by: Davidlohr Bueso <[email protected]>
Co-developed-by: Connor O'Brien <[email protected]>
Signed-off-by: Connor O'Brien <[email protected]>
Signed-off-by: John Stultz <[email protected]>
---
v2:
* Add LOCK08 config file suggested by Paul McKenney
v3:
* Minor commit message tweaks and naming changes
suggested by Davidlohr Bueso
v4:
* Add co-developed tag
---
kernel/locking/locktorture.c | 35 +++++++++++++++++++
.../selftests/rcutorture/configs/lock/CFLIST | 1 +
.../selftests/rcutorture/configs/lock/LOCK08 | 6 ++++
.../rcutorture/configs/lock/LOCK08.boot | 1 +
4 files changed, 43 insertions(+)
create mode 100644 tools/testing/selftests/rcutorture/configs/lock/LOCK08
create mode 100644 tools/testing/selftests/rcutorture/configs/lock/LOCK08.boot
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 6fe046594868..8a08c004aa80 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -332,6 +332,28 @@ static struct lock_torture_ops rw_lock_irq_ops = {
};
static DEFINE_MUTEX(torture_mutex);
+static struct mutex torture_nested_mutexes[MAX_NESTED_LOCKS];
+static struct lock_class_key nested_mutex_keys[MAX_NESTED_LOCKS];
+
+static void torture_mutex_init(void)
+{
+ int i;
+
+ for (i = 0; i < MAX_NESTED_LOCKS; i++)
+ __mutex_init(&torture_nested_mutexes[i], __func__,
+ &nested_mutex_keys[i]);
+}
+
+static int torture_mutex_nested_lock(int tid __maybe_unused,
+ u32 lockset)
+{
+ int i;
+
+ for (i = 0; i < nested_locks; i++)
+ if (lockset & (1 << i))
+ mutex_lock(&torture_nested_mutexes[i]);
+ return 0;
+}
static int torture_mutex_lock(int tid __maybe_unused)
__acquires(torture_mutex)
@@ -360,11 +382,24 @@ __releases(torture_mutex)
mutex_unlock(&torture_mutex);
}
+static void torture_mutex_nested_unlock(int tid __maybe_unused,
+ u32 lockset)
+{
+ int i;
+
+ for (i = nested_locks - 1; i >= 0; i--)
+ if (lockset & (1 << i))
+ mutex_unlock(&torture_nested_mutexes[i]);
+}
+
static struct lock_torture_ops mutex_lock_ops = {
+ .init = torture_mutex_init,
+ .nested_lock = torture_mutex_nested_lock,
.writelock = torture_mutex_lock,
.write_delay = torture_mutex_delay,
.task_boost = torture_boost_dummy,
.writeunlock = torture_mutex_unlock,
+ .nested_unlock = torture_mutex_nested_unlock,
.readlock = NULL,
.read_delay = NULL,
.readunlock = NULL,
diff --git a/tools/testing/selftests/rcutorture/configs/lock/CFLIST b/tools/testing/selftests/rcutorture/configs/lock/CFLIST
index 41bae5824339..a48bba0d35a6 100644
--- a/tools/testing/selftests/rcutorture/configs/lock/CFLIST
+++ b/tools/testing/selftests/rcutorture/configs/lock/CFLIST
@@ -5,3 +5,4 @@ LOCK04
LOCK05
LOCK06
LOCK07
+LOCK08
diff --git a/tools/testing/selftests/rcutorture/configs/lock/LOCK08 b/tools/testing/selftests/rcutorture/configs/lock/LOCK08
new file mode 100644
index 000000000000..1d1da1477fc3
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/lock/LOCK08
@@ -0,0 +1,6 @@
+CONFIG_SMP=y
+CONFIG_NR_CPUS=4
+CONFIG_HOTPLUG_CPU=y
+CONFIG_PREEMPT_NONE=n
+CONFIG_PREEMPT_VOLUNTARY=n
+CONFIG_PREEMPT=y
diff --git a/tools/testing/selftests/rcutorture/configs/lock/LOCK08.boot b/tools/testing/selftests/rcutorture/configs/lock/LOCK08.boot
new file mode 100644
index 000000000000..b8b6caebb89e
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/lock/LOCK08.boot
@@ -0,0 +1 @@
+locktorture.torture_type=mutex_lock locktorture.nested_locks=8
--
2.39.2.637.g21b0678d19-goog
This patch adds randomized nested locking to the rtmutex torture
tests. Additionally it adds LOCK09 config files for testing
rtmutexes with nested locking.
Cc: Davidlohr Bueso <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: [email protected]
Reviewed-by: Davidlohr Bueso <[email protected]>
Co-developed-by: Connor O'Brien <[email protected]>
Signed-off-by: Connor O'Brien <[email protected]>
Signed-off-by: John Stultz <[email protected]>
---
v2:
* Add LOCK09 config file suggested by Paul McKenney
v3:
* Minor commit message tweaks and naming changes
suggested by Davidlohr Bueso
v4:
* Add co-developed tag
---
kernel/locking/locktorture.c | 35 +++++++++++++++++++
.../selftests/rcutorture/configs/lock/CFLIST | 1 +
.../selftests/rcutorture/configs/lock/LOCK09 | 6 ++++
.../rcutorture/configs/lock/LOCK09.boot | 1 +
4 files changed, 43 insertions(+)
create mode 100644 tools/testing/selftests/rcutorture/configs/lock/LOCK09
create mode 100644 tools/testing/selftests/rcutorture/configs/lock/LOCK09.boot
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 8a08c004aa80..fd8b2b007c26 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -506,6 +506,28 @@ static struct lock_torture_ops ww_mutex_lock_ops = {
#ifdef CONFIG_RT_MUTEXES
static DEFINE_RT_MUTEX(torture_rtmutex);
+static struct rt_mutex torture_nested_rtmutexes[MAX_NESTED_LOCKS];
+static struct lock_class_key nested_rtmutex_keys[MAX_NESTED_LOCKS];
+
+static void torture_rtmutex_init(void)
+{
+ int i;
+
+ for (i = 0; i < MAX_NESTED_LOCKS; i++)
+ __rt_mutex_init(&torture_nested_rtmutexes[i], __func__,
+ &nested_rtmutex_keys[i]);
+}
+
+static int torture_rtmutex_nested_lock(int tid __maybe_unused,
+ u32 lockset)
+{
+ int i;
+
+ for (i = 0; i < nested_locks; i++)
+ if (lockset & (1 << i))
+ rt_mutex_lock(&torture_nested_rtmutexes[i]);
+ return 0;
+}
static int torture_rtmutex_lock(int tid __maybe_unused)
__acquires(torture_rtmutex)
@@ -570,11 +592,24 @@ __releases(torture_rtmutex)
rt_mutex_unlock(&torture_rtmutex);
}
+static void torture_rtmutex_nested_unlock(int tid __maybe_unused,
+ u32 lockset)
+{
+ int i;
+
+ for (i = nested_locks - 1; i >= 0; i--)
+ if (lockset & (1 << i))
+ rt_mutex_unlock(&torture_nested_rtmutexes[i]);
+}
+
static struct lock_torture_ops rtmutex_lock_ops = {
+ .init = torture_rtmutex_init,
+ .nested_lock = torture_rtmutex_nested_lock,
.writelock = torture_rtmutex_lock,
.write_delay = torture_rtmutex_delay,
.task_boost = torture_rtmutex_boost,
.writeunlock = torture_rtmutex_unlock,
+ .nested_unlock = torture_rtmutex_nested_unlock,
.readlock = NULL,
.read_delay = NULL,
.readunlock = NULL,
diff --git a/tools/testing/selftests/rcutorture/configs/lock/CFLIST b/tools/testing/selftests/rcutorture/configs/lock/CFLIST
index a48bba0d35a6..28e23d05d5a5 100644
--- a/tools/testing/selftests/rcutorture/configs/lock/CFLIST
+++ b/tools/testing/selftests/rcutorture/configs/lock/CFLIST
@@ -6,3 +6,4 @@ LOCK05
LOCK06
LOCK07
LOCK08
+LOCK09
diff --git a/tools/testing/selftests/rcutorture/configs/lock/LOCK09 b/tools/testing/selftests/rcutorture/configs/lock/LOCK09
new file mode 100644
index 000000000000..1d1da1477fc3
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/lock/LOCK09
@@ -0,0 +1,6 @@
+CONFIG_SMP=y
+CONFIG_NR_CPUS=4
+CONFIG_HOTPLUG_CPU=y
+CONFIG_PREEMPT_NONE=n
+CONFIG_PREEMPT_VOLUNTARY=n
+CONFIG_PREEMPT=y
diff --git a/tools/testing/selftests/rcutorture/configs/lock/LOCK09.boot b/tools/testing/selftests/rcutorture/configs/lock/LOCK09.boot
new file mode 100644
index 000000000000..fd5eff148a93
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/lock/LOCK09.boot
@@ -0,0 +1 @@
+locktorture.torture_type=rtmutex_lock locktorture.nested_locks=8
--
2.39.2.637.g21b0678d19-goog
If we're using nested locking to stress things, occasionally
skip taking the main lock, so that we can get some different
contention patterns between the writers (to hopefully get two
disjoint blocked trees)
Cc: Davidlohr Bueso <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: [email protected]
Co-developed-by: Connor O'Brien <[email protected]>
Signed-off-by: Connor O'Brien <[email protected]>
Signed-off-by: John Stultz <[email protected]>
---
v3:
* Minor rework for naming changes suggested by Davidlohr Bueso
* Added comment explaining why we skip the main lock, as
suggested by Davidlohr Bueso
v4:
* Add co-developed tag
---
kernel/locking/locktorture.c | 37 ++++++++++++++++++++++++++----------
1 file changed, 27 insertions(+), 10 deletions(-)
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index fd8b2b007c26..ab896cc42b87 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -745,6 +745,7 @@ static int lock_torture_writer(void *arg)
int tid = lwsp - cxt.lwsa;
DEFINE_TORTURE_RANDOM(rand);
u32 lockset_mask;
+ bool skip_main_lock;
VERBOSE_TOROUT_STRING("lock_torture_writer task started");
set_user_nice(current, MAX_NICE);
@@ -754,21 +755,37 @@ static int lock_torture_writer(void *arg)
schedule_timeout_uninterruptible(1);
lockset_mask = torture_random(&rand);
+ /*
+ * When using nested_locks, we want to occasionally
+ * skip the main lock so we can avoid always serializing
+ * the lock chains on that central lock. By skipping the
+ * main lock occasionally, we can create different
+ * contention patterns (allowing for multiple disjoint
+ * blocked trees)
+ */
+ skip_main_lock = (nested_locks &&
+ !(torture_random(&rand) % 100));
+
cxt.cur_ops->task_boost(&rand);
if (cxt.cur_ops->nested_lock)
cxt.cur_ops->nested_lock(tid, lockset_mask);
- cxt.cur_ops->writelock(tid);
- if (WARN_ON_ONCE(lock_is_write_held))
- lwsp->n_lock_fail++;
- lock_is_write_held = true;
- if (WARN_ON_ONCE(atomic_read(&lock_is_read_held)))
- lwsp->n_lock_fail++; /* rare, but... */
- lwsp->n_lock_acquired++;
+ if (!skip_main_lock) {
+ cxt.cur_ops->writelock(tid);
+ if (WARN_ON_ONCE(lock_is_write_held))
+ lwsp->n_lock_fail++;
+ lock_is_write_held = true;
+ if (WARN_ON_ONCE(atomic_read(&lock_is_read_held)))
+ lwsp->n_lock_fail++; /* rare, but... */
+
+ lwsp->n_lock_acquired++;
+ }
cxt.cur_ops->write_delay(&rand);
- lock_is_write_held = false;
- WRITE_ONCE(last_lock_release, jiffies);
- cxt.cur_ops->writeunlock(tid);
+ if (!skip_main_lock) {
+ lock_is_write_held = false;
+ WRITE_ONCE(last_lock_release, jiffies);
+ cxt.cur_ops->writeunlock(tid);
+ }
if (cxt.cur_ops->nested_unlock)
cxt.cur_ops->nested_unlock(tid, lockset_mask);
--
2.39.2.637.g21b0678d19-goog
On Tue, Feb 21, 2023 at 07:02:35PM +0000, John Stultz wrote:
> In order to extend locktorture to support lock nesting, add
> nested_lock() and nested_unlock() hooks to the torture ops.
>
> These take a 32bit lockset mask which is generated at random,
> so some number of locks will be taken before the main lock is
> taken and released afterwards.
>
> Additionally, add nested_locks module parameter to allow
> specifying the number of nested locks to be used.
>
> This has been helpful to uncover issues in the proxy-exec
> series development.
>
> This was inspired by locktorture extensions originally implemented
> by Connor O'Brien, for stress testing the proxy-execution series:
> https://lore.kernel.org/lkml/[email protected]/
>
> Cc: Davidlohr Bueso <[email protected]>
> Cc: "Paul E. McKenney" <[email protected]>
> Cc: Josh Triplett <[email protected]>
> Cc: Joel Fernandes <[email protected]>
> Cc: Juri Lelli <[email protected]>
> Cc: Valentin Schneider <[email protected]>
> Cc: Dietmar Eggemann <[email protected]>
> Cc: [email protected]
> Reviewed-by: Davidlohr Bueso <[email protected]>
> Co-developed-by: Connor O'Brien <[email protected]>
> Signed-off-by: Connor O'Brien <[email protected]>
> Signed-off-by: John Stultz <[email protected]>
I queued this series in place of its precedessor, thank you for the
update!
Given what I know now, I will set this up for the v6.4 merge window.
Thanx, Paul
> ---
> v3:
> * Minor commit message tweaks and naming changes
> suggested by Davidlohr Bueso
> v4:
> * Add co-developed tag
> ---
> kernel/locking/locktorture.c | 23 +++++++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
> index 9c2fb613a55d..6fe046594868 100644
> --- a/kernel/locking/locktorture.c
> +++ b/kernel/locking/locktorture.c
> @@ -48,6 +48,9 @@ torture_param(int, stat_interval, 60,
> torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
> torture_param(int, verbose, 1,
> "Enable verbose debugging printk()s");
> +torture_param(int, nested_locks, 0, "Number of nested locks (max = 8)");
> +/* Going much higher trips "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!" errors */
> +#define MAX_NESTED_LOCKS 8
>
> static char *torture_type = "spin_lock";
> module_param(torture_type, charp, 0444);
> @@ -76,10 +79,12 @@ static void lock_torture_cleanup(void);
> struct lock_torture_ops {
> void (*init)(void);
> void (*exit)(void);
> + int (*nested_lock)(int tid, u32 lockset);
> int (*writelock)(int tid);
> void (*write_delay)(struct torture_random_state *trsp);
> void (*task_boost)(struct torture_random_state *trsp);
> void (*writeunlock)(int tid);
> + void (*nested_unlock)(int tid, u32 lockset);
> int (*readlock)(int tid);
> void (*read_delay)(struct torture_random_state *trsp);
> void (*readunlock)(int tid);
> @@ -669,6 +674,7 @@ static int lock_torture_writer(void *arg)
> struct lock_stress_stats *lwsp = arg;
> int tid = lwsp - cxt.lwsa;
> DEFINE_TORTURE_RANDOM(rand);
> + u32 lockset_mask;
>
> VERBOSE_TOROUT_STRING("lock_torture_writer task started");
> set_user_nice(current, MAX_NICE);
> @@ -677,7 +683,10 @@ static int lock_torture_writer(void *arg)
> if ((torture_random(&rand) & 0xfffff) == 0)
> schedule_timeout_uninterruptible(1);
>
> + lockset_mask = torture_random(&rand);
> cxt.cur_ops->task_boost(&rand);
> + if (cxt.cur_ops->nested_lock)
> + cxt.cur_ops->nested_lock(tid, lockset_mask);
> cxt.cur_ops->writelock(tid);
> if (WARN_ON_ONCE(lock_is_write_held))
> lwsp->n_lock_fail++;
> @@ -690,6 +699,8 @@ static int lock_torture_writer(void *arg)
> lock_is_write_held = false;
> WRITE_ONCE(last_lock_release, jiffies);
> cxt.cur_ops->writeunlock(tid);
> + if (cxt.cur_ops->nested_unlock)
> + cxt.cur_ops->nested_unlock(tid, lockset_mask);
>
> stutter_wait("lock_torture_writer");
> } while (!torture_must_stop());
> @@ -830,11 +841,11 @@ lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
> const char *tag)
> {
> pr_alert("%s" TORTURE_FLAG
> - "--- %s%s: nwriters_stress=%d nreaders_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
> + "--- %s%s: nwriters_stress=%d nreaders_stress=%d nested_locks=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
> torture_type, tag, cxt.debug_lock ? " [debug]": "",
> - cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval,
> - verbose, shuffle_interval, stutter, shutdown_secs,
> - onoff_interval, onoff_holdoff);
> + cxt.nrealwriters_stress, cxt.nrealreaders_stress,
> + nested_locks, stat_interval, verbose, shuffle_interval,
> + stutter, shutdown_secs, onoff_interval, onoff_holdoff);
> }
>
> static void lock_torture_cleanup(void)
> @@ -1053,6 +1064,10 @@ static int __init lock_torture_init(void)
> }
> }
>
> + /* cap nested_locks to MAX_NESTED_LOCKS */
> + if (nested_locks > MAX_NESTED_LOCKS)
> + nested_locks = MAX_NESTED_LOCKS;
> +
> if (cxt.cur_ops->readlock) {
> reader_tasks = kcalloc(cxt.nrealreaders_stress,
> sizeof(reader_tasks[0]),
> --
> 2.39.2.637.g21b0678d19-goog
>
On Wed, Feb 22, 2023 at 11:07 AM Paul E. McKenney <[email protected]> wrote:
> On Tue, Feb 21, 2023 at 07:02:35PM +0000, John Stultz wrote:
> > In order to extend locktorture to support lock nesting, add
> > nested_lock() and nested_unlock() hooks to the torture ops.
> >
> > These take a 32bit lockset mask which is generated at random,
> > so some number of locks will be taken before the main lock is
> > taken and released afterwards.
> >
> > Additionally, add nested_locks module parameter to allow
> > specifying the number of nested locks to be used.
> >
> > This has been helpful to uncover issues in the proxy-exec
> > series development.
> >
> > This was inspired by locktorture extensions originally implemented
> > by Connor O'Brien, for stress testing the proxy-execution series:
> > https://lore.kernel.org/lkml/[email protected]/
> >
> > Cc: Davidlohr Bueso <[email protected]>
> > Cc: "Paul E. McKenney" <[email protected]>
> > Cc: Josh Triplett <[email protected]>
> > Cc: Joel Fernandes <[email protected]>
> > Cc: Juri Lelli <[email protected]>
> > Cc: Valentin Schneider <[email protected]>
> > Cc: Dietmar Eggemann <[email protected]>
> > Cc: [email protected]
> > Reviewed-by: Davidlohr Bueso <[email protected]>
> > Co-developed-by: Connor O'Brien <[email protected]>
> > Signed-off-by: Connor O'Brien <[email protected]>
> > Signed-off-by: John Stultz <[email protected]>
>
> I queued this series in place of its precedessor, thank you for the
> update!
>
> Given what I know now, I will set this up for the v6.4 merge window.
Much appreciated! Apologies for the churn, I wasn't sure if you caught
the last iteration or not, so I figured I'd send it out again.
thanks
-john