raid5-stats.patch

非常经典的一个分布式系统

Add RAID statistics counters to /proc/mdstat

Index: linux-2.6.9/include/linux/raid/raid5.h
===================================================================
--- linux-2.6.9.orig/include/linux/raid/raid5.h	2004-10-19 01:54:55.000000000 +0400
+++ linux-2.6.9/include/linux/raid/raid5.h	2006-05-17 14:10:53.000000000 +0400
@@ -222,6 +222,22 @@ struct raid5_private_data {
 	int			inactive_blocked;	/* release of inactive stripes blocked,
 							 * waiting for 25% to be free
 							 */        
+	/*
+	 * Stats
+	 */
+	atomic_t		reads_in;
+	atomic_t		writes_in;
+	atomic_t		reads_out;
+	atomic_t		writes_out;
+	atomic_t		handled_in_raid5d;
+	atomic_t		out_of_stripes;
+	atomic_t		reads_for_rmw;
+	atomic_t		reads_for_rcw;
+	atomic_t		handle_called;
+	atomic_t		delayed;
+	atomic_t		in_reqs_in_queue;
+	atomic_t		out_reqs_in_queue;
+
 	spinlock_t		device_lock;
 	struct disk_info	disks[0];
 };
Index: linux-2.6.9/drivers/md/raid5.c
===================================================================
--- linux-2.6.9.orig/drivers/md/raid5.c	2006-03-10 18:20:48.000000000 +0300
+++ linux-2.6.9/drivers/md/raid5.c	2006-05-17 14:10:53.000000000 +0400
@@ -77,9 +77,10 @@ static inline void __release_stripe(raid
 		if (atomic_read(&conf->active_stripes)==0)
 			BUG();
 		if (test_bit(STRIPE_HANDLE, &sh->state)) {
-			if (test_bit(STRIPE_DELAYED, &sh->state))
+			if (test_bit(STRIPE_DELAYED, &sh->state)) {
 				list_add_tail(&sh->lru, &conf->delayed_list);
-			else
+				atomic_inc(&conf->delayed);
+			} else
 				list_add_tail(&sh->lru, &conf->handle_list);
 			md_wakeup_thread(conf->mddev->thread);
 		} else {
@@ -250,6 +251,7 @@ static struct stripe_head *get_active_st
 			if (noblock && sh == NULL)
 				break;
 			if (!sh) {
+				atomic_inc(&conf->out_of_stripes);
 				conf->inactive_blocked = 1;
 				wait_event_lock_irq(conf->wait_for_stripe,
 						    !list_empty(&conf->inactive_list) &&
@@ -271,6 +273,8 @@ static struct stripe_head *get_active_st
 				if (list_empty(&sh->lru))
 					BUG();
 				list_del_init(&sh->lru);
+				if (test_bit(STRIPE_DELAYED, &sh->state))
+					atomic_dec(&conf->delayed);
 			}
 		}
 	} while (sh == NULL);
@@ -349,6 +353,8 @@ static int raid5_end_read_request (struc
 	if (bi->bi_size)
 		return 1;
 
+	atomic_dec(&conf->out_reqs_in_queue);
+
 	for (i=0 ; i<disks; i++)
 		if (bi == &sh->dev[i].req)
 			break;
@@ -422,6 +428,8 @@ static int raid5_end_write_request (stru
 	if (bi->bi_size)
 		return 1;
 
+	atomic_dec(&conf->out_reqs_in_queue);
+
 	for (i=0 ; i<disks; i++)
 		if (bi == &sh->dev[i].req)
 			break;
@@ -882,6 +890,7 @@ static void handle_stripe(struct stripe_
 	spin_lock(&sh->lock);
 	clear_bit(STRIPE_HANDLE, &sh->state);
 	clear_bit(STRIPE_DELAYED, &sh->state);
+	atomic_inc(&conf->handle_called);
 
 	syncing = test_bit(STRIPE_SYNCING, &sh->state);
 	/* Now to look around and see what can be done */
@@ -1127,6 +1136,7 @@ static void handle_stripe(struct stripe_
 						set_bit(R5_LOCKED, &dev->flags);
 						set_bit(R5_Wantread, &dev->flags);
 						locked++;
+						atomic_inc(&conf->reads_for_rmw);
 					} else {
 						set_bit(STRIPE_DELAYED, &sh->state);
 						set_bit(STRIPE_HANDLE, &sh->state);
@@ -1146,6 +1156,7 @@ static void handle_stripe(struct stripe_
 						set_bit(R5_LOCKED, &dev->flags);
 						set_bit(R5_Wantread, &dev->flags);
 						locked++;
+						atomic_inc(&conf->reads_for_rcw);
 					} else {
 						set_bit(STRIPE_DELAYED, &sh->state);
 						set_bit(STRIPE_HANDLE, &sh->state);
@@ -1228,6 +1239,7 @@ static void handle_stripe(struct stripe_
 		bi->bi_next = NULL;
 		bi->bi_size = 0;
 		bi->bi_end_io(bi, bytes, 0);
+		atomic_dec(&conf->in_reqs_in_queue);
 	}
 	for (i=disks; i-- ;) {
 		int rw;
@@ -1243,10 +1255,13 @@ static void handle_stripe(struct stripe_
 		bi = &sh->dev[i].req;
  
 		bi->bi_rw = rw;
-		if (rw)
+		if (rw) {
+			atomic_inc(&conf->writes_out);
 			bi->bi_end_io = raid5_end_write_request;
-		else
+		} else {
+			atomic_inc(&conf->reads_out);
 			bi->bi_end_io = raid5_end_read_request;
+		}
  
 		spin_lock_irq(&conf->device_lock);
 		rdev = conf->disks[i].rdev;
@@ -1274,6 +1289,7 @@ static void handle_stripe(struct stripe_
 			bi->bi_io_vec[0].bv_offset = 0;
 			bi->bi_size = STRIPE_SIZE;
 			bi->bi_next = NULL;
+			atomic_inc(&conf->out_reqs_in_queue);
 			generic_make_request(bi);
 		} else {
 			PRINTK("skip op %ld on disc %d for sector %llu\n",
@@ -1296,6 +1312,7 @@ static inline void raid5_activate_delaye
 			if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
 				atomic_inc(&conf->preread_active_stripes);
 			list_add_tail(&sh->lru, &conf->handle_list);
+			atomic_dec(&conf->delayed);
 		}
 	}
 }
@@ -1395,12 +1412,16 @@ static int make_request (request_queue_t
 	sector_t logical_sector, last_sector;
 	struct stripe_head *sh;
 
+	atomic_inc(&conf->in_reqs_in_queue);
+
 	if (bio_data_dir(bi)==WRITE) {
 		disk_stat_inc(mddev->gendisk, writes);
 		disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bi));
+		atomic_inc(&conf->writes_in);
 	} else {
 		disk_stat_inc(mddev->gendisk, reads);
 		disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bi));
+		atomic_inc(&conf->reads_in);
 	}
 
 	logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
@@ -1439,6 +1460,7 @@ static int make_request (request_queue_t
 
 		if ( bio_data_dir(bi) == WRITE )
 			md_write_end(mddev);
+		atomic_dec(&conf->in_reqs_in_queue);
 		bi->bi_size = 0;
 		bi->bi_end_io(bi, bytes, 0);
 	}
@@ -1535,6 +1557,7 @@ static void raid5d (mddev_t *mddev)
 		spin_unlock_irq(&conf->device_lock);
 		
 		handled++;
+		atomic_inc(&conf->handled_in_raid5d);
 		handle_stripe(sh);
 		release_stripe(sh);
 
@@ -1767,6 +1790,21 @@ static void status (struct seq_file *seq
 			       conf->disks[i].rdev &&
 			       conf->disks[i].rdev->in_sync ? "U" : "_");
 	seq_printf (seq, "]");
+	seq_printf (seq, "\n\t\tin: %u reads, %u writes; out: %u reads, %u writes",
+			atomic_read(&conf->reads_in), atomic_read(&conf->writes_in),
+			atomic_read(&conf->reads_out), atomic_read(&conf->writes_out));
+	seq_printf (seq, "\n\t\t%u in raid5d, %u out of stripes, %u handle called",
+			atomic_read(&conf->handled_in_raid5d),
+			atomic_read(&conf->out_of_stripes),
+			atomic_read(&conf->handle_called));
+	seq_printf (seq, "\n\t\treads: %u for rmw, %u for rcw",
+			atomic_read(&conf->reads_for_rmw),
+			atomic_read(&conf->reads_for_rcw));
+	seq_printf (seq, "\n\t\t%u delayed, %u active, queues: %u in, %u out\n",
+			atomic_read(&conf->delayed),
+			atomic_read(&conf->active_stripes),
+			atomic_read(&conf->in_reqs_in_queue),
+			atomic_read(&conf->out_reqs_in_queue));
 #if RAID5_DEBUG
 #define D(x) \
 	seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x))