locktorture: Introduce torture context

The amount of global variables is getting pretty ugly. Group variables
related to the execution (ie: not parameters) in a new context structure.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 82 insertions, 79 deletions

diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 8480118c0ca8..540d5dfe1112 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -66,29 +66,22 @@ torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
 torture_param(bool, verbose, true,
              "Enable verbose debugging printk()s");
 
-static bool debug_lock = false;
 static char *torture_type = "spin_lock";
 module_param(torture_type, charp, 0444);
 MODULE_PARM_DESC(torture_type,
                  "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)");
 
-static atomic_t n_lock_torture_errors;
-
 static struct task_struct *stats_task;
 static struct task_struct **writer_tasks;
 static struct task_struct **reader_tasks;
 
-static int nrealwriters_stress;
 static bool lock_is_write_held;
-static int nrealreaders_stress;
 static bool lock_is_read_held;
 
 struct lock_stress_stats {
         long n_lock_fail;
         long n_lock_acquired;
 };
-static struct lock_stress_stats *lwsa; /* writer statistics */
-static struct lock_stress_stats *lrsa; /* reader statistics */
 
 #if defined(MODULE)
 #define LOCKTORTURE_RUNNABLE_INIT 1
@@ -117,8 +110,18 @@ struct lock_torture_ops {
         const char *name;
 };
 
-static struct lock_torture_ops *cur_ops;
-
+struct lock_torture_cxt {
+        int nrealwriters_stress;
+        int nrealreaders_stress;
+        bool debug_lock;
+        atomic_t n_lock_torture_errors;
+        struct lock_torture_ops *cur_ops;
+        struct lock_stress_stats *lwsa; /* writer statistics */
+        struct lock_stress_stats *lrsa; /* reader statistics */
+};
+static struct lock_torture_cxt cxt = { 0, 0, false,
+                                       ATOMIC_INIT(0),
+                                       NULL, NULL};
 /*
  * Definitions for lock torture testing.
  */
@@ -134,10 +137,10 @@ static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
 
         /* We want a long delay occasionally to force massive contention.  */
         if (!(torture_random(trsp) %
-              (nrealwriters_stress * 2000 * longdelay_us)))
+              (cxt.nrealwriters_stress * 2000 * longdelay_us)))
                 mdelay(longdelay_us);
 #ifdef CONFIG_PREEMPT
-        if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+        if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
                 preempt_schedule();  /* Allow test to be preempted. */
 #endif
 }
@@ -174,13 +177,13 @@ static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
          * we want a long delay occasionally to force massive contention.
          */
         if (!(torture_random(trsp) %
-              (nrealwriters_stress * 2000 * longdelay_us)))
+              (cxt.nrealwriters_stress * 2000 * longdelay_us)))
                 mdelay(longdelay_us);
         if (!(torture_random(trsp) %
-              (nrealwriters_stress * 2 * shortdelay_us)))
+              (cxt.nrealwriters_stress * 2 * shortdelay_us)))
                 udelay(shortdelay_us);
 #ifdef CONFIG_PREEMPT
-        if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+        if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
                 preempt_schedule();  /* Allow test to be preempted. */
 #endif
 }
@@ -206,14 +209,14 @@ __acquires(torture_spinlock_irq)
         unsigned long flags;
 
         spin_lock_irqsave(&torture_spinlock, flags);
-        cur_ops->flags = flags;
+        cxt.cur_ops->flags = flags;
         return 0;
 }
 
 static void torture_lock_spin_write_unlock_irq(void)
 __releases(torture_spinlock)
 {
-        spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags);
+        spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags);
 }
 
 static struct lock_torture_ops spin_lock_irq_ops = {
@@ -240,12 +243,12 @@ static void torture_mutex_delay(struct torture_random_state *trsp)
 
         /* We want a long delay occasionally to force massive contention.  */
         if (!(torture_random(trsp) %
-              (nrealwriters_stress * 2000 * longdelay_ms)))
+              (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
                 mdelay(longdelay_ms * 5);
         else
                 mdelay(longdelay_ms / 5);
 #ifdef CONFIG_PREEMPT
-        if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+        if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
                 preempt_schedule();  /* Allow test to be preempted. */
 #endif
 }
@@ -278,12 +281,12 @@ static void torture_rwsem_write_delay(struct torture_random_state *trsp)
 
         /* We want a long delay occasionally to force massive contention.  */
         if (!(torture_random(trsp) %
-              (nrealwriters_stress * 2000 * longdelay_ms)))
+              (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
                 mdelay(longdelay_ms * 10);
         else
                 mdelay(longdelay_ms / 10);
 #ifdef CONFIG_PREEMPT
-        if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+        if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
                 preempt_schedule();  /* Allow test to be preempted. */
 #endif
 }
@@ -305,12 +308,12 @@ static void torture_rwsem_read_delay(struct torture_random_state *trsp)
 
         /* We want a long delay occasionally to force massive contention.  */
         if (!(torture_random(trsp) %
-              (nrealwriters_stress * 2000 * longdelay_ms)))
+              (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
                 mdelay(longdelay_ms * 2);
         else
                 mdelay(longdelay_ms / 2);
 #ifdef CONFIG_PREEMPT
-        if (!(torture_random(trsp) % (nrealreaders_stress * 20000)))
+        if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000)))
                 preempt_schedule();  /* Allow test to be preempted. */
 #endif
 }
@@ -345,14 +348,14 @@ static int lock_torture_writer(void *arg)
         do {
                 if ((torture_random(&rand) & 0xfffff) == 0)
                         schedule_timeout_uninterruptible(1);
-                cur_ops->writelock();
+                cxt.cur_ops->writelock();
                 if (WARN_ON_ONCE(lock_is_write_held))
                         lwsp->n_lock_fail++;
                 lock_is_write_held = 1;
                 lwsp->n_lock_acquired++;
-                cur_ops->write_delay(&rand);
+                cxt.cur_ops->write_delay(&rand);
                 lock_is_write_held = 0;
-                cur_ops->writeunlock();
+                cxt.cur_ops->writeunlock();
                 stutter_wait("lock_torture_writer");
         } while (!torture_must_stop());
         torture_kthread_stopping("lock_torture_writer");
@@ -374,12 +377,12 @@ static int lock_torture_reader(void *arg)
         do {
                 if ((torture_random(&rand) & 0xfffff) == 0)
                         schedule_timeout_uninterruptible(1);
-                cur_ops->readlock();
+                cxt.cur_ops->readlock();
                 lock_is_read_held = 1;
                 lrsp->n_lock_acquired++;
-                cur_ops->read_delay(&rand);
+                cxt.cur_ops->read_delay(&rand);
                 lock_is_read_held = 0;
-                cur_ops->readunlock();
+                cxt.cur_ops->readunlock();
                 stutter_wait("lock_torture_reader");
         } while (!torture_must_stop());
         torture_kthread_stopping("lock_torture_reader");
@@ -398,7 +401,7 @@ static void __torture_print_stats(char *page,
         long min = statp[0].n_lock_acquired;
         long long sum = 0;
 
-        n_stress = write ? nrealwriters_stress : nrealreaders_stress;
+        n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress;
         for (i = 0; i < n_stress; i++) {
                 if (statp[i].n_lock_fail)
                         fail = true;
@@ -414,7 +417,7 @@ static void __torture_print_stats(char *page,
                         sum, max, min, max / 2 > min ? "???" : "",
                         fail, fail ? "!!!" : "");
         if (fail)
-                atomic_inc(&n_lock_torture_errors);
+                atomic_inc(&cxt.n_lock_torture_errors);
 }
 
 /*
@@ -427,11 +430,11 @@ static void __torture_print_stats(char *page,
  */
 static void lock_torture_stats_print(void)
 {
-        int size = nrealwriters_stress * 200 + 8192;
+        int size = cxt.nrealwriters_stress * 200 + 8192;
         char *buf;
 
-        if (cur_ops->readlock)
-                size += nrealreaders_stress * 200 + 8192;
+        if (cxt.cur_ops->readlock)
+                size += cxt.nrealreaders_stress * 200 + 8192;
 
         buf = kmalloc(size, GFP_KERNEL);
         if (!buf) {
@@ -440,11 +443,11 @@ static void lock_torture_stats_print(void)
                 return;
         }
 
-        __torture_print_stats(buf, lwsa, true);
+        __torture_print_stats(buf, cxt.lwsa, true);
         pr_alert("%s", buf);
         kfree(buf);
 
-        if (cur_ops->readlock) {
+        if (cxt.cur_ops->readlock) {
                 buf = kmalloc(size, GFP_KERNEL);
                 if (!buf) {
                         pr_err("lock_torture_stats_print: Out of memory, need: %d",
@@ -452,7 +455,7 @@ static void lock_torture_stats_print(void)
                         return;
                 }
 
-                __torture_print_stats(buf, lrsa, false);
+                __torture_print_stats(buf, cxt.lrsa, false);
                 pr_alert("%s", buf);
                 kfree(buf);
         }
@@ -483,8 +486,8 @@ lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
 {
         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",
-                 torture_type, tag, debug_lock ? " [debug]": "",
-                 nrealwriters_stress, nrealreaders_stress, stat_interval,
+                 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);
 }
@@ -497,7 +500,7 @@ static void lock_torture_cleanup(void)
                 return;
 
         if (writer_tasks) {
-                for (i = 0; i < nrealwriters_stress; i++)
+                for (i = 0; i < cxt.nrealwriters_stress; i++)
                         torture_stop_kthread(lock_torture_writer,
                                              writer_tasks[i]);
                 kfree(writer_tasks);
@@ -505,7 +508,7 @@ static void lock_torture_cleanup(void)
         }
 
         if (reader_tasks) {
-                for (i = 0; i < nrealreaders_stress; i++)
+                for (i = 0; i < cxt.nrealreaders_stress; i++)
                         torture_stop_kthread(lock_torture_reader,
                                              reader_tasks[i]);
                 kfree(reader_tasks);
@@ -515,14 +518,14 @@ static void lock_torture_cleanup(void)
         torture_stop_kthread(lock_torture_stats, stats_task);
         lock_torture_stats_print();  /* -After- the stats thread is stopped! */
 
-        if (atomic_read(&n_lock_torture_errors))
-                lock_torture_print_module_parms(cur_ops,
+        if (atomic_read(&cxt.n_lock_torture_errors))
+                lock_torture_print_module_parms(cxt.cur_ops,
                                                 "End of test: FAILURE");
         else if (torture_onoff_failures())
-                lock_torture_print_module_parms(cur_ops,
+                lock_torture_print_module_parms(cxt.cur_ops,
                                                 "End of test: LOCK_HOTPLUG");
         else
-                lock_torture_print_module_parms(cur_ops,
+                lock_torture_print_module_parms(cxt.cur_ops,
                                                 "End of test: SUCCESS");
         torture_cleanup_end();
 }
@@ -541,8 +544,8 @@ static int __init lock_torture_init(void)
 
         /* Process args and tell the world that the torturer is on the job. */
         for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
-                cur_ops = torture_ops[i];
-                if (strcmp(torture_type, cur_ops->name) == 0)
+                cxt.cur_ops = torture_ops[i];
+                if (strcmp(torture_type, cxt.cur_ops->name) == 0)
                         break;
         }
         if (i == ARRAY_SIZE(torture_ops)) {
@@ -555,40 +558,40 @@ static int __init lock_torture_init(void)
                 torture_init_end();
                 return -EINVAL;
         }
-        if (cur_ops->init)
-                cur_ops->init(); /* no "goto unwind" prior to this point!!! */
+        if (cxt.cur_ops->init)
+                cxt.cur_ops->init(); /* no "goto unwind" prior to this point!!! */
 
         if (nwriters_stress >= 0)
-                nrealwriters_stress = nwriters_stress;
+                cxt.nrealwriters_stress = nwriters_stress;
         else
-                nrealwriters_stress = 2 * num_online_cpus();
+                cxt.nrealwriters_stress = 2 * num_online_cpus();
 
 #ifdef CONFIG_DEBUG_MUTEXES
         if (strncmp(torture_type, "mutex", 5) == 0)
-                debug_lock = true;
+                cxt.debug_lock = true;
 #endif
 #ifdef CONFIG_DEBUG_SPINLOCK
         if (strncmp(torture_type, "spin", 4) == 0)
-                debug_lock = true;
+                cxt.debug_lock = true;
 #endif
 
         /* Initialize the statistics so that each run gets its own numbers. */
 
         lock_is_write_held = 0;
-        lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL);
-        if (lwsa == NULL) {
-                VERBOSE_TOROUT_STRING("lwsa: Out of memory");
+        cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL);
+        if (cxt.lwsa == NULL) {
+                VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory");
                 firsterr = -ENOMEM;
                 goto unwind;
         }
-        for (i = 0; i < nrealwriters_stress; i++) {
-                lwsa[i].n_lock_fail = 0;
-                lwsa[i].n_lock_acquired = 0;
+        for (i = 0; i < cxt.nrealwriters_stress; i++) {
+                cxt.lwsa[i].n_lock_fail = 0;
+                cxt.lwsa[i].n_lock_acquired = 0;
         }
 
-        if (cur_ops->readlock) {
+        if (cxt.cur_ops->readlock) {
                 if (nreaders_stress >= 0)
-                        nrealreaders_stress = nreaders_stress;
+                        cxt.nrealreaders_stress = nreaders_stress;
                 else {
                         /*
                          * By default distribute evenly the number of
@@ -596,25 +599,25 @@ static int __init lock_torture_init(void)
                          * of threads as the writer-only locks default.
                          */
                         if (nwriters_stress < 0) /* user doesn't care */
-                                nrealwriters_stress = num_online_cpus();
-                        nrealreaders_stress = nrealwriters_stress;
+                                cxt.nrealwriters_stress = num_online_cpus();
+                        cxt.nrealreaders_stress = cxt.nrealwriters_stress;
                 }
 
                 lock_is_read_held = 0;
-                lrsa = kmalloc(sizeof(*lrsa) * nrealreaders_stress, GFP_KERNEL);
-                if (lrsa == NULL) {
-                        VERBOSE_TOROUT_STRING("lrsa: Out of memory");
+                cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL);
+                if (cxt.lrsa == NULL) {
+                        VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory");
                         firsterr = -ENOMEM;
-                        kfree(lwsa);
+                        kfree(cxt.lwsa);
                         goto unwind;
                 }
 
-                for (i = 0; i < nrealreaders_stress; i++) {
-                        lrsa[i].n_lock_fail = 0;
-                        lrsa[i].n_lock_acquired = 0;
+                for (i = 0; i < cxt.nrealreaders_stress; i++) {
+                        cxt.lrsa[i].n_lock_fail = 0;
+                        cxt.lrsa[i].n_lock_acquired = 0;
                 }
         }
-        lock_torture_print_module_parms(cur_ops, "Start of test");
+        lock_torture_print_module_parms(cxt.cur_ops, "Start of test");
 
         /* Prepare torture context. */
         if (onoff_interval > 0) {
@@ -640,7 +643,7 @@ static int __init lock_torture_init(void)
                         goto unwind;
         }
 
-        writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]),
+        writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]),
                                GFP_KERNEL);
         if (writer_tasks == NULL) {
                 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
@@ -648,8 +651,8 @@ static int __init lock_torture_init(void)
                 goto unwind;
         }
 
-        if (cur_ops->readlock) {
-                reader_tasks = kzalloc(nrealreaders_stress * sizeof(reader_tasks[0]),
+        if (cxt.cur_ops->readlock) {
+                reader_tasks = kzalloc(cxt.nrealreaders_stress * sizeof(reader_tasks[0]),
                                        GFP_KERNEL);
                 if (reader_tasks == NULL) {
                         VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
@@ -666,22 +669,22 @@ static int __init lock_torture_init(void)
          * for very specific needs, or even let the user choose the policy, if
          * ever wanted.
          */
-        for (i = 0, j = 0; i < nrealwriters_stress ||
-                    j < nrealreaders_stress; i++, j++) {
-                if (i >= nrealwriters_stress)
+        for (i = 0, j = 0; i < cxt.nrealwriters_stress ||
+                    j < cxt.nrealreaders_stress; i++, j++) {
+                if (i >= cxt.nrealwriters_stress)
                         goto create_reader;
 
                 /* Create writer. */
-                firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i],
+                firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i],
                                                   writer_tasks[i]);
                 if (firsterr)
                         goto unwind;
 
         create_reader:
-                if (cur_ops->readlock == NULL || (j >= nrealreaders_stress))
+                if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
                         continue;
                 /* Create reader. */
-                firsterr = torture_create_kthread(lock_torture_reader, &lrsa[j],
+                firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j],
                                                   reader_tasks[j]);
                 if (firsterr)
                         goto unwind;