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Source Path: svn/ trunk/ ddsnap/ patches/ 2.6.24.2/ bio.throttle.patch

‹ r1516 r1735

diff -purN linux-2.6.24.2/block/ll_rw_blk.c linux-2.6.24.2-new/block/ll_rw_blk.c
--- linux-2.6.24.2/block/ll_rw_blk.c	2008-02-10 21:51:11.000000000 -0800
+++ linux-2.6.24.2-new/block/ll_rw_blk.c	2008-06-02 16:23:00.000000000 -0700
@@ -3210,9 +3210,9 @@ static inline int bio_check_eod(struct b
  */
 static inline void __generic_make_request(struct bio *bio)
 {
-	struct request_queue *q;
+	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	sector_t old_sector;
-	int ret, nr_sectors = bio_sectors(bio);
+	int nr_sectors = bio_sectors(bio);
 	dev_t old_dev;
 	int err = -EIO;
 
@@ -3221,6 +3221,13 @@ static inline void __generic_make_reques
 	if (bio_check_eod(bio, nr_sectors))
 		goto end_io;
 
+	if (q && q->metric && !bio->bi_queue) {
+		int need = bio->bi_max_vecs;
+		bio->bi_queue = q;
+		/* FIXME: potential race if atomic_sub is called in the middle of condition check */
+		wait_event(q->throttle_wait, atomic_read(&q->available) >= need);
+		atomic_sub(need, &q->available);
+	}
 	/*
 	 * Resolve the mapping until finished. (drivers are
 	 * still free to implement/resolve their own stacking
@@ -3231,10 +3238,9 @@ static inline void __generic_make_reques
 	 */
 	old_sector = -1;
 	old_dev = 0;
-	do {
+	while (1) {
 		char b[BDEVNAME_SIZE];
 
-		q = bdev_get_queue(bio->bi_bdev);
 		if (!q) {
 			printk(KERN_ERR
 			       "generic_make_request: Trying to access "
@@ -3282,8 +3288,10 @@ end_io:
 			goto end_io;
 		}
 
-		ret = q->make_request_fn(q, bio);
-	} while (ret);
+		if (!q->make_request_fn(q, bio))
+			return;
+		q = bdev_get_queue(bio->bi_bdev);
+	}
 }
 
 /*
diff -purN linux-2.6.24.2/drivers/md/dm.c linux-2.6.24.2-new/drivers/md/dm.c
--- linux-2.6.24.2/drivers/md/dm.c	2008-02-10 21:51:11.000000000 -0800
+++ linux-2.6.24.2-new/drivers/md/dm.c	2008-06-02 16:32:05.000000000 -0700
@@ -22,6 +22,7 @@
 #include <linux/hdreg.h>
 #include <linux/blktrace_api.h>
 #include <linux/smp_lock.h>
+#include <linux/sysctl.h>
 
 #define DM_MSG_PREFIX "core"
 
@@ -130,6 +131,43 @@ struct mapped_device {
 #define MIN_IOS 256
 static struct kmem_cache *_io_cache;
 static struct kmem_cache *_tio_cache;
+static int sysctl_bio_throttle = 0;
+
+static ctl_table dm_table[] = {
+	{
+		.ctl_name	= DEV_DM_BIO_THROTTLE,
+		.procname	= "bio_throttle",
+		.data		= &sysctl_bio_throttle,
+		.maxlen		= sizeof(int),
+		.mode           = S_IRUGO|S_IWUSR,
+		.proc_handler   = &proc_dointvec,
+	},
+	{ .ctl_name = 0 }
+};
+
+static ctl_table dm_dir_table[] = {
+	{
+		.ctl_name	= DEV_DM,
+		.procname	= "dm",
+		.maxlen		= 0,
+		.mode		= S_IRUGO|S_IXUGO,
+		.child		= dm_table,
+	},
+	{ .ctl_name = 0 }
+};
+
+static struct ctl_table_header *dm_table_header;
+
+static ctl_table dm_root_table[] = {
+	{
+		.ctl_name	= CTL_DEV,
+		.procname	= "dev",
+		.maxlen		= 0,
+		.mode		= 0555,
+		.child		= dm_dir_table,
+	},
+	{ .ctl_name = 0 }
+};
 
 static int __init local_init(void)
 {
@@ -209,6 +247,7 @@ static int __init dm_init(void)
 			goto bad;
 	}
 
+	dm_table_header = register_sysctl_table(dm_root_table);
 	return 0;
 
       bad:
@@ -224,6 +263,7 @@ static void __exit dm_exit(void)
 
 	while (i--)
 		_exits[i]();
+	unregister_sysctl_table(dm_table_header);
 }
 
 /*
@@ -809,6 +849,11 @@ static int __split_bio(struct mapped_dev
  * CRUD END
  *---------------------------------------------------------------*/
 
+static unsigned dm_metric(struct bio *bio)
+{
+	return 1;
+}
+
 /*
  * The request function that just remaps the bio built up by
  * dm_merge_bvec.
@@ -967,6 +1012,7 @@ out:
 
 static struct block_device_operations dm_blk_dops;
 
+#define DEFAULT_THROTTLE_CAPACITY 1000
 /*
  * Allocate and initialise a blank device with a given minor.
  */
@@ -1009,6 +1055,13 @@ static struct mapped_device *alloc_dev(i
 		goto bad1_free_minor;
 
 	md->queue->queuedata = md;
+	if (sysctl_bio_throttle == 1) {
+		md->queue->metric = dm_metric;
+		/* A dm device constructor may change the throttle capacity */
+		atomic_set(&md->queue->available, md->queue->capacity = DEFAULT_THROTTLE_CAPACITY);
+		init_waitqueue_head(&md->queue->throttle_wait);
+	}
+
 	md->queue->backing_dev_info.congested_fn = dm_any_congested;
 	md->queue->backing_dev_info.congested_data = md;
 	blk_queue_make_request(md->queue, dm_request);
@@ -1571,6 +1624,7 @@ int dm_suspended(struct mapped_device *m
 {
 	return test_bit(DMF_SUSPENDED, &md->flags);
 }
+EXPORT_SYMBOL_GPL(dm_suspended);
 
 int dm_noflush_suspending(struct dm_target *ti)
 {
diff -purN linux-2.6.24.2/fs/bio.c linux-2.6.24.2-new/fs/bio.c
--- linux-2.6.24.2/fs/bio.c	2008-02-10 21:51:11.000000000 -0800
+++ linux-2.6.24.2-new/fs/bio.c	2008-06-02 16:23:00.000000000 -0700
@@ -1007,6 +1007,13 @@ void bio_endio(struct bio *bio, int erro
 	else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
 		error = -EIO;
 
+	if (bio->bi_queue) {
+		struct request_queue *q = bio->bi_queue;
+		atomic_add(bio->bi_max_vecs, &q->available);
+		bio->bi_queue = NULL; /* 0xdeadbeef? */
+		wake_up(&q->throttle_wait);
+	}
+
 	if (bio->bi_end_io)
 		bio->bi_end_io(bio, error);
 }
diff -purN linux-2.6.24.2/include/linux/bio.h linux-2.6.24.2-new/include/linux/bio.h
--- linux-2.6.24.2/include/linux/bio.h	2008-02-10 21:51:11.000000000 -0800
+++ linux-2.6.24.2-new/include/linux/bio.h	2008-06-02 16:23:00.000000000 -0700
@@ -111,6 +111,7 @@ struct bio {
 	bio_end_io_t		*bi_end_io;
 	atomic_t		bi_cnt;		/* pin count */
 
+	struct request_queue	*bi_queue;	/* for throttling */
 	void			*bi_private;
 
 	bio_destructor_t	*bi_destructor;	/* destructor */
diff -purN linux-2.6.24.2/include/linux/blkdev.h linux-2.6.24.2-new/include/linux/blkdev.h
--- linux-2.6.24.2/include/linux/blkdev.h	2008-02-10 21:51:11.000000000 -0800
+++ linux-2.6.24.2-new/include/linux/blkdev.h	2008-06-02 16:23:00.000000000 -0700
@@ -384,6 +384,10 @@ struct request_queue
 	struct work_struct	unplug_work;
 
 	struct backing_dev_info	backing_dev_info;
+	unsigned (*metric)(struct bio *bio);	/* (stub) bio throttle metric */
+	wait_queue_head_t	throttle_wait;
+	atomic_t		available;
+	unsigned		capacity;
 
 	/*
 	 * The queue owner gets to use this for whatever they like.
diff -purN linux-2.6.24.2/include/linux/sysctl.h linux-2.6.24.2-new/include/linux/sysctl.h
--- linux-2.6.24.2/include/linux/sysctl.h	2008-02-10 21:51:11.000000000 -0800
+++ linux-2.6.24.2-new/include/linux/sysctl.h	2008-06-02 16:24:11.000000000 -0700
@@ -859,6 +859,7 @@ enum {
 	DEV_MAC_HID=5,
 	DEV_SCSI=6,
 	DEV_IPMI=7,
+	DEV_DM=8
 };
 
 /* /proc/sys/dev/cdrom */
@@ -882,6 +883,11 @@ enum {
 	DEV_RAID_SPEED_LIMIT_MAX=2
 };
 
+/* /proc/sys/dev/dm */
+enum {
+	DEV_DM_BIO_THROTTLE = 1
+};
+
 /* /proc/sys/dev/parport/default */
 enum {
 	DEV_PARPORT_DEFAULT_TIMESLICE=1,
diff -purN linux-2.6.24.2/kernel/sysctl_check.c linux-2.6.24.2-new/kernel/sysctl_check.c
--- linux-2.6.24.2/kernel/sysctl_check.c	2008-02-10 21:51:11.000000000 -0800
+++ linux-2.6.24.2-new/kernel/sysctl_check.c	2008-06-02 16:24:11.000000000 -0700
@@ -875,6 +875,11 @@ static struct trans_ctl_table trans_parp
 	{}
 };
 
+static struct trans_ctl_table trans_dm_table[] = {
+	{ DEV_DM_BIO_THROTTLE,	"bio_throttle" },
+	{}
+};
+
 static struct trans_ctl_table trans_dev_table[] = {
 	{ DEV_CDROM,	"cdrom",	trans_cdrom_table },
 	/* DEV_HWMON unused */
@@ -883,6 +888,7 @@ static struct trans_ctl_table trans_dev_
 	{ DEV_MAC_HID,	"mac_hid",	trans_mac_hid_files },
 	{ DEV_SCSI,	"scsi",		trans_scsi_table },
 	{ DEV_IPMI,	"ipmi",		trans_ipmi_table },
+	{ DEV_DM,	"dm",		trans_dm_table },
 	{}
 };

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Change log

r1689 by jiahotcake on Jun 05, 2008 Diff

Add a sysctl interface
/proc/sys/dev/dm/bio_throttle to
enable/disable
bio throttling. bio throttling is turned
off by default for now.
Also changed the dm_inflight() function to
get inflight bios from
the gendisk structure so it does not
depend on the bio_throttling patch
and merged it with ddsnap.base.patch.

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Older revisions

r1516 by jiahotcake on Apr 01, 2008 Diff

Fix the hanging problem in 2.6.24
bio.throttle.patch.
See  issue 96 .

r1483 by Daniel.Raymond.Phillips on Mar 21, 2008 Diff

Fix 2.6.24 bio.throttle patch

r1476 by Daniel.Raymond.Phillips on Mar 20, 2008 Diff

Fix bio.throttle patch context, rebase
dm.inflight.patch

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