Re: [PATCH tip/core/rcu 37/55] rcutorture: Abstract torture_create_kthread()
From: Paul E. McKenney
Date: Tue Feb 18 2014 - 16:36:27 EST
On Mon, Feb 17, 2014 at 04:34:02PM -0800, Josh Triplett wrote:
> On Mon, Feb 17, 2014 at 02:12:41PM -0800, Paul E. McKenney wrote:
> > From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
> >
> > Creation of kthreads is not RCU-specific, so this commit abstracts
> > out torture_create_kthread(), saving a few tens of lines of code in
> > the process.
> >
> > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
>
> One comment below.
>
> > include/linux/torture.h | 8 +++-
> > kernel/rcu/rcutorture.c | 98 ++++++++++---------------------------------------
> > kernel/torture.c | 80 +++++++++++++++++-----------------------
> > 3 files changed, 60 insertions(+), 126 deletions(-)
> >
> > diff --git a/include/linux/torture.h b/include/linux/torture.h
> > index db9bc7756a32..e5264c6ecfeb 100644
> > --- a/include/linux/torture.h
> > +++ b/include/linux/torture.h
> > @@ -47,7 +47,7 @@
> > #define VERBOSE_TOROUT_STRING(s) \
> > do { if (verbose) pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); } while (0)
> > #define VERBOSE_TOROUT_ERRSTRING(s) \
> > - do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
> > + do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0)
>
> This change is also unrelated, and should not occur in this commit.
It is required for the invocation in _torture_create_kthread() below.
I have updated the commit log to call this out.
Thanx, Paul
> - Josh Triplett
>
> > /* Definitions for a non-string torture-test module parameter. */
> > #define torture_parm(type, name, init, msg) \
> > @@ -89,5 +89,11 @@ bool torture_cleanup(void);
> > bool torture_must_stop(void);
> > bool torture_must_stop_irq(void);
> > void torture_kthread_stopping(char *title);
> > +int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
> > + char *f, struct task_struct **tp);
> > +
> > +#define torture_create_kthread(n, arg, tp) \
> > + _torture_create_kthread(n, (arg), #n, "Creating " #n " task", \
> > + "Failed to create " #n, &(tp))
> >
> > #endif /* __LINUX_TORTURE_H */
> > diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
> > index cf365160b44f..951a5559d9fa 100644
> > --- a/kernel/rcu/rcutorture.c
> > +++ b/kernel/rcu/rcutorture.c
> > @@ -1104,19 +1104,9 @@ static int rcu_torture_stall(void *args)
> > /* Spawn CPU-stall kthread, if stall_cpu specified. */
> > static int __init rcu_torture_stall_init(void)
> > {
> > - int ret;
> > -
> > if (stall_cpu <= 0)
> > return 0;
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_stall task");
> > - stall_task = kthread_run(rcu_torture_stall, NULL, "rcu_torture_stall");
> > - if (IS_ERR(stall_task)) {
> > - ret = PTR_ERR(stall_task);
> > - stall_task = NULL;
> > - return ret;
> > - }
> > - torture_shuffle_task_register(stall_task);
> > - return 0;
> > + return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
> > }
> >
> > /* Clean up after the CPU-stall kthread, if one was spawned. */
> > @@ -1225,29 +1215,13 @@ static int rcu_torture_barrier_init(void)
> > return -ENOMEM;
> > for (i = 0; i < n_barrier_cbs; i++) {
> > init_waitqueue_head(&barrier_cbs_wq[i]);
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_barrier_cbs task");
> > - barrier_cbs_tasks[i] = kthread_run(rcu_torture_barrier_cbs,
> > - (void *)(long)i,
> > - "rcu_torture_barrier_cbs");
> > - if (IS_ERR(barrier_cbs_tasks[i])) {
> > - ret = PTR_ERR(barrier_cbs_tasks[i]);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create rcu_torture_barrier_cbs");
> > - barrier_cbs_tasks[i] = NULL;
> > + ret = torture_create_kthread(rcu_torture_barrier_cbs,
> > + (void *)(long)i,
> > + barrier_cbs_tasks[i]);
> > + if (ret)
> > return ret;
> > - }
> > - torture_shuffle_task_register(barrier_cbs_tasks[i]);
> > }
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_barrier task");
> > - barrier_task = kthread_run(rcu_torture_barrier, NULL,
> > - "rcu_torture_barrier");
> > - if (IS_ERR(barrier_task)) {
> > - ret = PTR_ERR(barrier_task);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create rcu_torture_barrier");
> > - barrier_task = NULL;
> > - return ret;
> > - }
> > - torture_shuffle_task_register(barrier_task);
> > - return 0;
> > + return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
> > }
> >
> > /* Clean up after RCU barrier testing. */
> > @@ -1515,17 +1489,10 @@ rcu_torture_init(void)
> >
> > /* Start up the kthreads. */
> >
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_writer task");
> > - writer_task = kthread_create(rcu_torture_writer, NULL,
> > - "rcu_torture_writer");
> > - if (IS_ERR(writer_task)) {
> > - firsterr = PTR_ERR(writer_task);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create writer");
> > - writer_task = NULL;
> > + firsterr = torture_create_kthread(rcu_torture_writer, NULL,
> > + writer_task);
> > + if (firsterr)
> > goto unwind;
> > - }
> > - torture_shuffle_task_register(writer_task);
> > - wake_up_process(writer_task);
> > fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
> > GFP_KERNEL);
> > if (fakewriter_tasks == NULL) {
> > @@ -1534,16 +1501,10 @@ rcu_torture_init(void)
> > goto unwind;
> > }
> > for (i = 0; i < nfakewriters; i++) {
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_fakewriter task");
> > - fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
> > - "rcu_torture_fakewriter");
> > - if (IS_ERR(fakewriter_tasks[i])) {
> > - firsterr = PTR_ERR(fakewriter_tasks[i]);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create fakewriter");
> > - fakewriter_tasks[i] = NULL;
> > + firsterr = torture_create_kthread(rcu_torture_fakewriter,
> > + NULL, fakewriter_tasks[i]);
> > + if (firsterr)
> > goto unwind;
> > - }
> > - torture_shuffle_task_register(fakewriter_tasks[i]);
> > }
> > reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
> > GFP_KERNEL);
> > @@ -1553,28 +1514,16 @@ rcu_torture_init(void)
> > goto unwind;
> > }
> > for (i = 0; i < nrealreaders; i++) {
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_reader task");
> > - reader_tasks[i] = kthread_run(rcu_torture_reader, NULL,
> > - "rcu_torture_reader");
> > - if (IS_ERR(reader_tasks[i])) {
> > - firsterr = PTR_ERR(reader_tasks[i]);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create reader");
> > - reader_tasks[i] = NULL;
> > + firsterr = torture_create_kthread(rcu_torture_reader, NULL,
> > + reader_tasks[i]);
> > + if (firsterr)
> > goto unwind;
> > - }
> > - torture_shuffle_task_register(reader_tasks[i]);
> > }
> > if (stat_interval > 0) {
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_stats task");
> > - stats_task = kthread_run(rcu_torture_stats, NULL,
> > - "rcu_torture_stats");
> > - if (IS_ERR(stats_task)) {
> > - firsterr = PTR_ERR(stats_task);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create stats");
> > - stats_task = NULL;
> > + firsterr = torture_create_kthread(rcu_torture_stats, NULL,
> > + stats_task);
> > + if (firsterr)
> > goto unwind;
> > - }
> > - torture_shuffle_task_register(stats_task);
> > }
> > if (test_no_idle_hz) {
> > firsterr = torture_shuffle_init(shuffle_interval * HZ);
> > @@ -1592,16 +1541,9 @@ rcu_torture_init(void)
> > fqs_duration = 0;
> > if (fqs_duration) {
> > /* Create the fqs thread */
> > - VERBOSE_TOROUT_STRING("Creating rcu_torture_fqs task");
> > - fqs_task = kthread_run(rcu_torture_fqs, NULL,
> > - "rcu_torture_fqs");
> > - if (IS_ERR(fqs_task)) {
> > - firsterr = PTR_ERR(fqs_task);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create fqs");
> > - fqs_task = NULL;
> > + torture_create_kthread(rcu_torture_fqs, NULL, fqs_task);
> > + if (firsterr)
> > goto unwind;
> > - }
> > - torture_shuffle_task_register(fqs_task);
> > }
> > if (test_boost_interval < 1)
> > test_boost_interval = 1;
> > diff --git a/kernel/torture.c b/kernel/torture.c
> > index 6f1c6600d183..94760f0f2923 100644
> > --- a/kernel/torture.c
> > +++ b/kernel/torture.c
> > @@ -180,23 +180,16 @@ torture_onoff(void *arg)
> > */
> > int torture_onoff_init(long ooholdoff, long oointerval)
> > {
> > -#ifdef CONFIG_HOTPLUG_CPU
> > - int ret;
> > + int ret = 0;
> >
> > +#ifdef CONFIG_HOTPLUG_CPU
> > onoff_holdoff = ooholdoff;
> > onoff_interval = oointerval;
> > if (onoff_interval <= 0)
> > return 0;
> > - VERBOSE_TOROUT_STRING("Creating torture_onoff task");
> > - onoff_task = kthread_run(torture_onoff, NULL, "torture_onoff");
> > - if (IS_ERR(onoff_task)) {
> > - ret = PTR_ERR(onoff_task);
> > - onoff_task = NULL;
> > - return ret;
> > - }
> > - torture_shuffle_task_register(onoff_task);
> > + ret = torture_create_kthread(torture_onoff, NULL, onoff_task);
> > #endif /* #ifdef CONFIG_HOTPLUG_CPU */
> > - return 0;
> > + return ret;
> > }
> > EXPORT_SYMBOL_GPL(torture_onoff_init);
> >
> > @@ -379,8 +372,6 @@ static int torture_shuffle(void *arg)
> > */
> > int torture_shuffle_init(long shuffint)
> > {
> > - int ret;
> > -
> > shuffle_interval = shuffint;
> >
> > shuffle_idle_cpu = -1;
> > @@ -391,17 +382,7 @@ int torture_shuffle_init(long shuffint)
> > }
> >
> > /* Create the shuffler thread */
> > - VERBOSE_TOROUT_STRING("Creating torture_shuffle task");
> > - shuffler_task = kthread_run(torture_shuffle, NULL, "torture_shuffle");
> > - if (IS_ERR(shuffler_task)) {
> > - ret = PTR_ERR(shuffler_task);
> > - free_cpumask_var(shuffle_tmp_mask);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create shuffler");
> > - shuffler_task = NULL;
> > - return ret;
> > - }
> > - torture_shuffle_task_register(shuffler_task);
> > - return 0;
> > + return torture_create_kthread(torture_shuffle, NULL, shuffler_task);
> > }
> > EXPORT_SYMBOL_GPL(torture_shuffle_init);
> >
> > @@ -483,25 +464,16 @@ static int torture_shutdown(void *arg)
> > */
> > int torture_shutdown_init(int ssecs, void (*cleanup)(void))
> > {
> > - int ret;
> > + int ret = 0;
> >
> > shutdown_secs = ssecs;
> > torture_shutdown_hook = cleanup;
> > if (shutdown_secs > 0) {
> > - VERBOSE_TOROUT_STRING("Creating torture_shutdown task");
> > shutdown_time = jiffies + shutdown_secs * HZ;
> > - shutdown_task = kthread_create(torture_shutdown, NULL,
> > - "torture_shutdown");
> > - if (IS_ERR(shutdown_task)) {
> > - ret = PTR_ERR(shutdown_task);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create shutdown");
> > - shutdown_task = NULL;
> > - return ret;
> > - }
> > - torture_shuffle_task_register(shutdown_task);
> > - wake_up_process(shutdown_task);
> > + ret = torture_create_kthread(torture_shutdown, NULL,
> > + shutdown_task);
> > }
> > - return 0;
> > + return ret;
> > }
> > EXPORT_SYMBOL_GPL(torture_shutdown_init);
> >
> > @@ -595,16 +567,8 @@ int torture_stutter_init(int s)
> > int ret;
> >
> > stutter = s;
> > - VERBOSE_TOROUT_STRING("Creating torture_stutter task");
> > - stutter_task = kthread_run(torture_stutter, NULL, "torture_stutter");
> > - if (IS_ERR(stutter_task)) {
> > - ret = PTR_ERR(stutter_task);
> > - VERBOSE_TOROUT_ERRSTRING("Failed to create stutter");
> > - stutter_task = NULL;
> > - return ret;
> > - }
> > - torture_shuffle_task_register(stutter_task);
> > - return 0;
> > + ret = torture_create_kthread(torture_stutter, NULL, stutter_task);
> > + return ret;
> > }
> > EXPORT_SYMBOL_GPL(torture_stutter_init);
> >
> > @@ -714,3 +678,25 @@ void torture_kthread_stopping(char *title)
> > }
> > }
> > EXPORT_SYMBOL_GPL(torture_kthread_stopping);
> > +
> > +/*
> > + * Create a generic torture kthread that is immediately runnable. If you
> > + * need the kthread to be stopped so that you can do something to it before
> > + * it starts, you will need to open-code your own.
> > + */
> > +int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
> > + char *f, struct task_struct **tp)
> > +{
> > + int ret = 0;
> > +
> > + VERBOSE_TOROUT_STRING(m);
> > + *tp = kthread_run(fn, arg, s);
> > + if (IS_ERR(*tp)) {
> > + ret = PTR_ERR(*tp);
> > + VERBOSE_TOROUT_ERRSTRING(f);
> > + *tp = NULL;
> > + }
> > + torture_shuffle_task_register(*tp);
> > + return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(_torture_create_kthread);
> > --
> > 1.8.1.5
> >
>
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