update test
authorcompudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Sun, 17 Aug 2008 06:58:34 +0000 (06:58 +0000)
committercompudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Sun, 17 Aug 2008 06:58:34 +0000 (06:58 +0000)
git-svn-id: http://ltt.polymtl.ca/svn@3025 04897980-b3bd-0310-b5e0-8ef037075253

trunk/tests/kernel/test-fair-rwlock.c

index 64aa29f9ca397d555127b820780faa82360e013a..dc17953259282c24da8e1343cfc62211224587ca 100644 (file)
 #include <linux/delay.h>
 #include <linux/hardirq.h>
 #include <linux/module.h>
+#include <linux/percpu.h>
 #include <asm/ptrace.h>
 
-#if (NR_CPUS > 512 && (BITS_PER_LONG == 32 || NR_CPUS > 1048576))
+#if (NR_CPUS > 64 && (BITS_PER_LONG == 32 || NR_CPUS > 32768))
 #error "fair rwlock needs more bits per long to deal with that many CPUs"
 #endif
 
 #define HARDIRQ_ROFFSET        ((SOFTIRQ_RMASK | THREAD_RMASK) + 1)
 #define HARDIRQ_RMASK  ((NR_CPUS - 1) * HARDIRQ_ROFFSET)
 
-#define THREAD_WMASK   ((HARDIRQ_RMASK | SOFTIRQ_RMASK | THREAD_RMASK) + 1)
-#define SOFTIRQ_WMASK  (THREAD_WMASK << 1)
+#define SUBSCRIBERS_WOFFSET    \
+       ((HARDIRQ_RMASK | SOFTIRQ_RMASK | THREAD_RMASK) + 1)
+#define SUBSCRIBERS_WMASK      \
+       ((NR_CPUS - 1) * SUBSCRIBERS_WOFFSET)
+#define WRITER_MUTEX           \
+       ((SUBSCRIBERS_WMASK | HARDIRQ_RMASK | SOFTIRQ_RMASK | THREAD_RMASK) + 1)
+#define SOFTIRQ_WMASK  (WRITER_MUTEX << 1)
+#define SOFTIRQ_WOFFSET        SOFTIRQ_WMASK
 #define HARDIRQ_WMASK  (SOFTIRQ_WMASK << 1)
+#define HARDIRQ_WOFFSET        HARDIRQ_WMASK
 
 #define NR_VARS 100
 #define NR_WRITERS 3
@@ -40,7 +48,6 @@ static struct task_struct *interrupt_reader;
 
 static struct fair_rwlock frwlock = {
        .value = ATOMIC_LONG_INIT(0),
-       .wlock = __SPIN_LOCK_UNLOCKED(&frwlock.wlock),
 };
 
 struct proc_dir_entry *pentry = NULL;
@@ -50,11 +57,16 @@ static int reader_thread(void *data)
        int i;
        int prev, cur;
        unsigned long iter = 0;
+       cycles_t time1, time2, delaymax = 0;
 
        printk("reader_thread/%lu runnning\n", (unsigned long)data);
        do {
                iter++;
+               preempt_disable();      /* for get_cycles accuracy */
+               time1 = get_cycles();
                fair_read_lock(&frwlock);
+               time2 = get_cycles();
+               delaymax = max(delaymax, time2 - time1);
                prev = var[0];
                for (i = 1; i < NR_VARS; i++) {
                        cur = var[i];
@@ -64,19 +76,35 @@ static int reader_thread(void *data)
                                "in thread\n", cur, prev, i, iter);
                }
                fair_read_unlock(&frwlock);
+               preempt_enable();       /* for get_cycles accuracy */
                //msleep(100);
        } while (!kthread_should_stop());
-       printk("reader_thread/%lu iterations : %lu\n",
-                       (unsigned long)data, iter);
+       printk("reader_thread/%lu iterations : %lu, "
+               "max contention %llu cycles\n",
+               (unsigned long)data, iter, delaymax);
        return 0;
 }
 
+DEFINE_PER_CPU(cycles_t, int_delaymax);
+
 static void interrupt_reader_ipi(void *data)
 {
        int i;
        int prev, cur;
+       cycles_t time1, time2;
+       cycles_t *delaymax;
+
+       /*
+        * Skip the ipi caller, not in irq context.
+        */
+       if (!in_irq())
+               return;
 
+       delaymax = &per_cpu(int_delaymax, smp_processor_id());
+       time1 = get_cycles();
        fair_read_lock(&frwlock);
+       time2 = get_cycles();
+       *delaymax = max(*delaymax, time2 - time1);
        prev = var[0];
        for (i = 1; i < NR_VARS; i++) {
                cur = var[i];
@@ -91,6 +119,8 @@ static void interrupt_reader_ipi(void *data)
 static int interrupt_reader_thread(void *data)
 {
        unsigned long iter = 0;
+       int i;
+
        do {
                iter++;
                on_each_cpu(interrupt_reader_ipi, NULL, 0);
@@ -98,6 +128,11 @@ static int interrupt_reader_thread(void *data)
        } while (!kthread_should_stop());
        printk("interrupt_reader_thread/%lu iterations : %lu\n",
                        (unsigned long)data, iter);
+       for_each_online_cpu(i) {
+               printk("interrupt readers on CPU %i, "
+                       "max contention : %llu cycles\n",
+                       i, per_cpu(int_delaymax, i));
+       }
        return 0;
 }
 
@@ -106,22 +141,29 @@ static int writer_thread(void *data)
        int i;
        int new;
        unsigned long iter = 0;
+       cycles_t time1, time2, delaymax = 0;
 
        printk("writer_thread/%lu runnning\n", (unsigned long)data);
        do {
                iter++;
+               preempt_disable();      /* for get_cycles accuracy */
+               time1 = get_cycles();
                fair_write_lock_irq(&frwlock);
                //fair_write_lock(&frwlock);
+               time2 = get_cycles();
+               delaymax = max(delaymax, time2 - time1);
                new = (int)get_cycles();
                for (i = 0; i < NR_VARS; i++) {
                        var[i] = new;
                }
                //fair_write_unlock(&frwlock);
                fair_write_unlock_irq(&frwlock);
+               preempt_enable();       /* for get_cycles accuracy */
                //msleep(100);
        } while (!kthread_should_stop());
-       printk("writer_thread/%lu iterations : %lu\n",
-                       (unsigned long)data, iter);
+       printk("writer_thread/%lu iterations : %lu, "
+               "max contention %llu cycles\n",
+               (unsigned long)data, iter, delaymax);
        return 0;
 }
 
@@ -152,15 +194,15 @@ static void fair_rwlock_stop(void)
 {
        unsigned long i;
 
+       for (i = 0; i < NR_WRITERS; i++) {
+               kthread_stop(writer_threads[i]);
+       }
+
        for (i = 0; i < NR_READERS; i++) {
                kthread_stop(reader_threads[i]);
        }
 
-       //kthread_stop(interrupt_reader);
-
-       for (i = 0; i < NR_WRITERS; i++) {
-               kthread_stop(writer_threads[i]);
-       }
+       kthread_stop(interrupt_reader);
 }
 
 
@@ -193,12 +235,14 @@ int init_module(void)
        printk("NR_CPUS : %d\n", NR_CPUS);
        printk("THREAD_ROFFSET : %lX\n", THREAD_ROFFSET);
        printk("THREAD_RMASK : %lX\n", THREAD_RMASK);
-       printk("THREAD_WMASK : %lX\n", THREAD_WMASK);
        printk("SOFTIRQ_ROFFSET : %lX\n", SOFTIRQ_ROFFSET);
        printk("SOFTIRQ_RMASK : %lX\n", SOFTIRQ_RMASK);
-       printk("SOFTIRQ_WMASK : %lX\n", SOFTIRQ_WMASK);
        printk("HARDIRQ_ROFFSET : %lX\n", HARDIRQ_ROFFSET);
        printk("HARDIRQ_RMASK : %lX\n", HARDIRQ_RMASK);
+       printk("SUBSCRIBERS_WOFFSET : %lX\n", SUBSCRIBERS_WOFFSET);
+       printk("SUBSCRIBERS_WMASK : %lX\n", SUBSCRIBERS_WMASK);
+       printk("WRITER_MUTEX : %lX\n", WRITER_MUTEX);
+       printk("SOFTIRQ_WMASK : %lX\n", SOFTIRQ_WMASK);
        printk("HARDIRQ_WMASK : %lX\n", HARDIRQ_WMASK);
 
        return 0;
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