5 #include <linux/module.h>
6 #include <linux/proc_fs.h>
7 #include <linux/sched.h>
8 #include <linux/timex.h>
9 #include <linux/fair-rwlock.h>
10 #include <linux/kthread.h>
11 #include <linux/delay.h>
12 #include <linux/hardirq.h>
13 #include <linux/module.h>
14 #include <asm/ptrace.h>
16 #if (NR_CPUS > 512 && (BITS_PER_LONG == 32 || NR_CPUS > 1048576))
17 #error "fair rwlock needs more bits per long to deal with that many CPUs"
20 #define THREAD_ROFFSET 1UL
21 #define THREAD_RMASK ((NR_CPUS - 1) * THREAD_ROFFSET)
22 #define SOFTIRQ_ROFFSET (THREAD_RMASK + 1)
23 #define SOFTIRQ_RMASK ((NR_CPUS - 1) * SOFTIRQ_ROFFSET)
24 #define HARDIRQ_ROFFSET ((SOFTIRQ_RMASK | THREAD_RMASK) + 1)
25 #define HARDIRQ_RMASK ((NR_CPUS - 1) * HARDIRQ_ROFFSET)
27 #define THREAD_WMASK (1UL << (BITS_PER_LONG - 3))
28 #define SOFTIRQ_WMASK (1UL << (BITS_PER_LONG - 2))
29 #define HARDIRQ_WMASK (1UL << (BITS_PER_LONG - 1))
35 #define NR_INTERRUPT_READERS 2
37 static int var
[NR_VARS
];
38 static struct task_struct
*reader_threads
[NR_READERS
];
39 static struct task_struct
*writer_threads
[NR_WRITERS
];
40 static struct task_struct
*interrupt_reader
;
42 static struct fair_rwlock frwlock
= {
43 .value
= ATOMIC_LONG_INIT(0),
44 .wlock
= __SPIN_LOCK_UNLOCKED(&frwlock
.wlock
),
47 struct proc_dir_entry
*pentry
= NULL
;
49 static int reader_thread(void *data
)
53 unsigned long iter
= 0;
55 printk("reader_thread/%lu runnning\n", (unsigned long)data
);
58 fair_read_lock(&frwlock
);
60 for (i
= 1; i
< NR_VARS
; i
++) {
64 "Unequal cur %d/prev %d at i %d, iter %lu "
65 "in thread\n", cur
, prev
, i
, iter
);
67 fair_read_unlock(&frwlock
);
69 } while (!kthread_should_stop());
70 printk("reader_thread/%lu iterations : %lu\n",
71 (unsigned long)data
, iter
);
75 static void interrupt_reader_ipi(void *data
)
80 fair_read_lock(&frwlock
);
82 for (i
= 1; i
< NR_VARS
; i
++) {
86 "Unequal cur %d/prev %d at i %d in interrupt\n",
89 fair_read_unlock(&frwlock
);
92 static int interrupt_reader_thread(void *data
)
94 unsigned long iter
= 0;
97 on_each_cpu(interrupt_reader_ipi
, NULL
, 0);
99 } while (!kthread_should_stop());
100 printk("interrupt_reader_thread/%lu iterations : %lu\n",
101 (unsigned long)data
, iter
);
105 static int writer_thread(void *data
)
109 unsigned long iter
= 0;
111 printk("writer_thread/%lu runnning\n", (unsigned long)data
);
114 fair_write_lock_irq(&frwlock
);
115 //fair_write_lock(&frwlock);
116 new = (int)get_cycles();
117 for (i
= 0; i
< NR_VARS
; i
++) {
120 //fair_write_unlock(&frwlock);
121 fair_write_unlock_irq(&frwlock
);
123 } while (!kthread_should_stop());
124 printk("writer_thread/%lu iterations : %lu\n",
125 (unsigned long)data
, iter
);
129 static void fair_rwlock_create(void)
133 for (i
= 0; i
< NR_READERS
; i
++) {
134 printk("starting reader thread %lu\n", i
);
135 reader_threads
[i
] = kthread_run(reader_thread
, (void *)i
,
137 BUG_ON(!reader_threads
[i
]);
140 printk("starting interrupt reader %lu\n", i
);
141 interrupt_reader
= kthread_run(interrupt_reader_thread
, NULL
,
142 "frwlock_interrupt_reader");
144 for (i
= 0; i
< NR_WRITERS
; i
++) {
145 printk("starting writer thread %lu\n", i
);
146 writer_threads
[i
] = kthread_run(writer_thread
, (void *)i
,
148 BUG_ON(!writer_threads
[i
]);
152 static void fair_rwlock_stop(void)
156 for (i
= 0; i
< NR_READERS
; i
++) {
157 kthread_stop(reader_threads
[i
]);
160 //kthread_stop(interrupt_reader);
162 for (i
= 0; i
< NR_WRITERS
; i
++) {
163 kthread_stop(writer_threads
[i
]);
168 static void perform_test(const char *name
, void (*callback
)(void))
170 printk("%s\n", name
);
174 static int my_open(struct inode
*inode
, struct file
*file
)
176 perform_test("fair-rwlock-create", fair_rwlock_create
);
178 perform_test("fair-rwlock-stop", fair_rwlock_stop
);
184 static struct file_operations my_operations
= {
188 int init_module(void)
190 pentry
= create_proc_entry("testfrwlock", 0444, NULL
);
192 pentry
->proc_fops
= &my_operations
;
194 printk("NR_CPUS : %d\n", NR_CPUS
);
195 printk("THREAD_ROFFSET : %lX\n", THREAD_ROFFSET
);
196 printk("THREAD_RMASK : %lX\n", THREAD_RMASK
);
197 printk("THREAD_WMASK : %lX\n", THREAD_WMASK
);
198 printk("SOFTIRQ_ROFFSET : %lX\n", SOFTIRQ_ROFFSET
);
199 printk("SOFTIRQ_RMASK : %lX\n", SOFTIRQ_RMASK
);
200 printk("SOFTIRQ_WMASK : %lX\n", SOFTIRQ_WMASK
);
201 printk("HARDIRQ_ROFFSET : %lX\n", HARDIRQ_ROFFSET
);
202 printk("HARDIRQ_RMASK : %lX\n", HARDIRQ_RMASK
);
203 printk("HARDIRQ_WMASK : %lX\n", HARDIRQ_WMASK
);
208 void cleanup_module(void)
210 remove_proc_entry("testfrwlock", NULL
);
213 MODULE_LICENSE("GPL");
214 MODULE_AUTHOR("Mathieu Desnoyers");
215 MODULE_DESCRIPTION("Fair rwlock test");