bio.throttle.patch - zumastor

‹r1516

r1735

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

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 },
 	{}
 };

Show details Hide details

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.

Go to:

Project members, sign in to write a code review

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

All revisions of this file

File info

Size: 7457 bytes, 255 lines

View raw file