Commit 22084190 authored by Vivek Goyal's avatar Vivek Goyal Committed by Jens Axboe
Browse files

blkio: Export disk time and sectors used by a group to user space 



o Export disk time and sector used by a group to user space through cgroup
  interface.

o Also export a "dequeue" interface to cgroup which keeps track of how many
  a times a group was deleted from service tree. Helps in debugging.

Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 2868ef7b

block/blk-cgroup.c

+63 −1
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
 * 	              Nauman Rafique <nauman@google.com>

 */

#include <linux/ioprio.h>

#include <linux/seq_file.h>

#include <linux/kdev_t.h>

#include "blk-cgroup.h"



extern void cfq_unlink_blkio_group(void *, struct blkio_group *);
@@ -23,8 +25,15 @@ struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) 
			    struct blkio_cgroup, css);

}



void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,

			unsigned long time, unsigned long sectors)

{

	blkg->time += time;

	blkg->sectors += sectors;

}



void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,

				struct blkio_group *blkg, void *key)

			struct blkio_group *blkg, void *key, dev_t dev)

{

	unsigned long flags;
@@ -37,6 +46,7 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, 
	/* Need to take css reference ? */

	cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));

#endif

	blkg->dev = dev;

}



static void __blkiocg_del_blkio_group(struct blkio_group *blkg)
@@ -115,12 +125,64 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) 
	return 0;

}



#define SHOW_FUNCTION_PER_GROUP(__VAR)					\

static int blkiocg_##__VAR##_read(struct cgroup *cgroup,		\

			struct cftype *cftype, struct seq_file *m)	\

{									\

	struct blkio_cgroup *blkcg;					\

	struct blkio_group *blkg;					\

	struct hlist_node *n;						\

									\

	if (!cgroup_lock_live_group(cgroup))				\

		return -ENODEV;						\

									\

	blkcg = cgroup_to_blkio_cgroup(cgroup);				\

	rcu_read_lock();						\

	hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\

		if (blkg->dev)						\

			seq_printf(m, "%u:%u %lu\n", MAJOR(blkg->dev),	\

				 MINOR(blkg->dev), blkg->__VAR);	\

	}								\

	rcu_read_unlock();						\

	cgroup_unlock();						\

	return 0;							\

}



SHOW_FUNCTION_PER_GROUP(time);

SHOW_FUNCTION_PER_GROUP(sectors);

#ifdef CONFIG_DEBUG_BLK_CGROUP

SHOW_FUNCTION_PER_GROUP(dequeue);

#endif

#undef SHOW_FUNCTION_PER_GROUP



#ifdef CONFIG_DEBUG_BLK_CGROUP

void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,

			unsigned long dequeue)

{

	blkg->dequeue += dequeue;

}

#endif



struct cftype blkio_files[] = {

	{

		.name = "weight",

		.read_u64 = blkiocg_weight_read,

		.write_u64 = blkiocg_weight_write,

	},

	{

		.name = "time",

		.read_seq_string = blkiocg_time_read,

	},

	{

		.name = "sectors",

		.read_seq_string = blkiocg_sectors_read,

	},

#ifdef CONFIG_DEBUG_BLK_CGROUP

       {

		.name = "dequeue",

		.read_seq_string = blkiocg_dequeue_read,

       },

#endif

};



static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup)

block/blk-cgroup.h

+20 −2
Original line number Diff line number Diff line
@@ -30,7 +30,15 @@ struct blkio_group { 
#ifdef CONFIG_DEBUG_BLK_CGROUP

	/* Store cgroup path */

	char path[128];

	/* How many times this group has been removed from service tree */

	unsigned long dequeue;

#endif

	/* The device MKDEV(major, minor), this group has been created for */

	dev_t   dev;



	/* total disk time and nr sectors dispatched by this group */

	unsigned long time;

	unsigned long sectors;

};



#define BLKIO_WEIGHT_MIN	100
@@ -42,24 +50,30 @@ static inline char *blkg_path(struct blkio_group *blkg) 
{

	return blkg->path;

}

void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,

				unsigned long dequeue);

#else

static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }

static inline void blkiocg_update_blkio_group_dequeue_stats(

			struct blkio_group *blkg, unsigned long dequeue) {}

#endif



#ifdef CONFIG_BLK_CGROUP

extern struct blkio_cgroup blkio_root_cgroup;

extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);

extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,

				struct blkio_group *blkg, void *key);

			struct blkio_group *blkg, void *key, dev_t dev);

extern int blkiocg_del_blkio_group(struct blkio_group *blkg);

extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,

						void *key);

void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,

			unsigned long time, unsigned long sectors);

#else

static inline struct blkio_cgroup *

cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }



static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,

			struct blkio_group *blkg, void *key)

			struct blkio_group *blkg, void *key, dev_t dev)

{

}
@@ -68,5 +82,9 @@ blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; } 


static inline struct blkio_group *

blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }

static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,

			unsigned long time, unsigned long sectors)

{

}

#endif

#endif /* _BLK_CGROUP_H */

block/cfq-iosched.c

+16 −3
Original line number Diff line number Diff line
@@ -143,6 +143,8 @@ struct cfq_queue { 
	struct cfq_rb_root *service_tree;

	struct cfq_queue *new_cfqq;

	struct cfq_group *cfqg;

	/* Sectors dispatched in current dispatch round */

	unsigned long nr_sectors;

};



/*
@@ -852,6 +854,7 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) 
	if (!RB_EMPTY_NODE(&cfqg->rb_node))

		cfq_rb_erase(&cfqg->rb_node, st);

	cfqg->saved_workload_slice = 0;

	blkiocg_update_blkio_group_dequeue_stats(&cfqg->blkg, 1);

}



static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq)
@@ -878,7 +881,8 @@ static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) 
			slice_used = allocated_slice;

	}



	cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u", slice_used);

	cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u sect=%lu", slice_used,

				cfqq->nr_sectors);

	return slice_used;

}
@@ -906,6 +910,8 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, 


	cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,

					st->min_vdisktime);

	blkiocg_update_blkio_group_stats(&cfqg->blkg, used_sl,

						cfqq->nr_sectors);

}



#ifdef CONFIG_CFQ_GROUP_IOSCHED
@@ -924,6 +930,8 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) 
	void *key = cfqd;

	int i, j;

	struct cfq_rb_root *st;

	struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;

	unsigned int major, minor;



	/* Do we need to take this reference */

	if (!css_tryget(&blkcg->css))
@@ -951,7 +959,9 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) 
	atomic_set(&cfqg->ref, 1);



	/* Add group onto cgroup list */

	blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd);

	sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);

	blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,

					MKDEV(major, minor));



	/* Add group on cfqd list */

	hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
@@ -1478,6 +1488,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd, 
		cfqq->dispatch_start = jiffies;

		cfqq->slice_end = 0;

		cfqq->slice_dispatch = 0;

		cfqq->nr_sectors = 0;



		cfq_clear_cfqq_wait_request(cfqq);

		cfq_clear_cfqq_must_dispatch(cfqq);
@@ -1801,6 +1812,7 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) 


	if (cfq_cfqq_sync(cfqq))

		cfqd->sync_flight++;

	cfqq->nr_sectors += blk_rq_sectors(rq);

}



/*
@@ -3513,7 +3525,8 @@ static void *cfq_init_queue(struct request_queue *q) 
	 * to make sure that cfq_put_cfqg() does not try to kfree root group

	 */

	atomic_set(&cfqg->ref, 1);

	blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd);

	blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd,

					0);

#endif

	/*

	 * Not strictly needed (since RB_ROOT just clears the node and we