[media] saa7164: measure via histograms various irq and queue latencies

saa7164: measure via histograms various irq and queue latencies
Attempting to determine where buffering issues under high load are due
to highly latent irq or work queue handling.

Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/saa7164/saa7164-core.c

@@ -142,14 +142,38 @@ static void saa7164_histogram_reset(struct saa7164_histogram *hg, char *name)
 
 	/* 200 - 2000ms x 100ms  */
 	for (i = 0; i < 15; i++) {
-		hg->counter1[48 + i].val = 200 + (i * 100);
+		hg->counter1[48 + i].val = 200 + (i * 200);
 	}
 
-	/* Catch all massive value (1hr) */
+	/* Catch all massive value (2secs) */
+	hg->counter1[55].val = 2000;
+
+	/* Catch all massive value (4secs) */
+	hg->counter1[56].val = 4000;
+
+	/* Catch all massive value (8secs) */
+	hg->counter1[57].val = 8000;
+
+	/* Catch all massive value (15secs) */
+	hg->counter1[58].val = 15000;
+
+	/* Catch all massive value (30secs) */
+	hg->counter1[59].val = 30000;
+
+	/* Catch all massive value (60secs) */
+	hg->counter1[60].val = 60000;
+
+	/* Catch all massive value (5mins) */
+	hg->counter1[61].val = 300000;
+
+	/* Catch all massive value (15mins) */
+	hg->counter1[62].val = 900000;
+
+	/* Catch all massive values (1hr) */
 	hg->counter1[63].val = 3600000;
 }
 
-static void saa7164_histogram_update(struct saa7164_histogram *hg, u32 val)
+void saa7164_histogram_update(struct saa7164_histogram *hg, u32 val)
 {
 	int i;
 	for (i = 0; i < 64; i++ ) {
@@ -168,7 +192,7 @@ static void saa7164_histogram_print(struct saa7164_port *port,
 	u32 entries = 0;
 	int i;
 
-	printk(KERN_ERR "Histogram named %s\n", hg->name);
+	printk(KERN_ERR "Histogram named %s (ms, count, last_update_jiffy)\n", hg->name);
 	for (i = 0; i < 64; i++ ) {
 		if (hg->counter1[i].count == 0)
 			continue;
@@ -285,6 +309,8 @@ static void saa7164_work_enchandler(struct work_struct *w)
 		saa7164_histogram_print(port, &port->irq_interval);
 		saa7164_histogram_print(port, &port->svc_interval);
 		saa7164_histogram_print(port, &port->irq_svc_interval);
+		saa7164_histogram_print(port, &port->read_interval);
+		saa7164_histogram_print(port, &port->poll_interval);
 		print_histogram = 64 + port->nr;
 	}
 }
@@ -731,6 +757,10 @@ static int saa7164_port_init(struct saa7164_dev *dev, int portnr)
 	saa7164_histogram_reset(&port->svc_interval, "deferred intervals");
 	saa7164_histogram_reset(&port->irq_svc_interval,
 		"irq to deferred intervals");
+	saa7164_histogram_reset(&port->read_interval,
+		"encoder read() intervals");
+	saa7164_histogram_reset(&port->poll_interval,
+		"encoder poll() intervals");
 
 	return 0;
 }
@@ -1016,6 +1046,10 @@ static void __devexit saa7164_finidev(struct pci_dev *pci_dev)
 		&dev->ports[ SAA7164_PORT_ENC1 ].svc_interval);
 	saa7164_histogram_print(&dev->ports[ SAA7164_PORT_ENC1 ],
 		&dev->ports[ SAA7164_PORT_ENC1 ].irq_svc_interval);
+	saa7164_histogram_print(&dev->ports[ SAA7164_PORT_ENC1 ],
+		&dev->ports[ SAA7164_PORT_ENC1 ].read_interval);
+	saa7164_histogram_print(&dev->ports[ SAA7164_PORT_ENC1 ],
+		&dev->ports[ SAA7164_PORT_ENC1 ].poll_interval);
 
 	saa7164_shutdown(dev);
 

drivers/media/video/saa7164/saa7164-encoder.c

@@ -1030,6 +1030,14 @@ static ssize_t fops_read(struct file *file, char __user *buffer,
 	int rem, cnt;
 	u8 *p;
 
+	port->last_read_msecs_diff = port->last_read_msecs;
+	port->last_read_msecs = jiffies_to_msecs(jiffies);
+	port->last_read_msecs_diff = port->last_read_msecs -
+		port->last_read_msecs_diff;
+
+	saa7164_histogram_update(&port->read_interval,
+		port->last_read_msecs_diff);
+
 	if (*pos)
 		return -ESPIPE;
 
@@ -1114,6 +1122,14 @@ static unsigned int fops_poll(struct file *file, poll_table *wait)
 	struct saa7164_user_buffer *ubuf;
 	unsigned int mask = 0;
 
+	port->last_poll_msecs_diff = port->last_poll_msecs;
+	port->last_poll_msecs = jiffies_to_msecs(jiffies);
+	port->last_poll_msecs_diff = port->last_poll_msecs -
+		port->last_poll_msecs_diff;
+
+	saa7164_histogram_update(&port->poll_interval,
+		port->last_poll_msecs_diff);
+
 	if (!video_is_registered(port->v4l_device)) {
 		return -EIO;
 	}

drivers/media/video/saa7164/saa7164.h

@@ -328,10 +328,14 @@ struct saa7164_port {
 	u32 last_irq_wp, last_svc_wp;
 	u32 last_irq_rp, last_svc_rp;
 	u64 last_irq_svc_msecs_diff;
+	u64 last_read_msecs, last_read_msecs_diff;
+	u64 last_poll_msecs, last_poll_msecs_diff;
 
 	struct saa7164_histogram irq_interval;
 	struct saa7164_histogram svc_interval;
 	struct saa7164_histogram irq_svc_interval;
+	struct saa7164_histogram read_interval;
+	struct saa7164_histogram poll_interval;
 
 	/* --- DVB Transport Specific --- */
 	struct saa7164_dvb dvb;
@@ -441,6 +445,7 @@ void saa7164_dumpregs(struct saa7164_dev *dev, u32 addr);
 void saa7164_dumphex16(struct saa7164_dev *dev, u8 *buf, int len);
 void saa7164_getfirmwarestatus(struct saa7164_dev *dev);
 u32 saa7164_getcurrentfirmwareversion(struct saa7164_dev *dev);
+void saa7164_histogram_update(struct saa7164_histogram *hg, u32 val);
 
 /* ----------------------------------------------------------- */
 /* saa7164-fw.c                                                */