blkio: Changes to IO controller additional stats patches
that include some minor fixes and addresses all comments.
Changelog: (most based on Vivek Goyal's comments)
o renamed blkiocg_reset_write to blkiocg_reset_stats
o more clarification in the documentation on io_service_time and io_wait_time
o Initialize blkg->stats_lock
o rename io_add_stat to blkio_add_stat and declare it static
o use bool for direction and sync
o derive direction and sync info from existing rq methods
o use 12 for major:minor string length
o define io_service_time better to cover the NCQ case
o add a separate reset_stats interface
o make the indexed stats a 2d array to simplify macro and function pointer code
o blkio.time now exports in jiffies as before
o Added stats description in patch description and
Documentation/cgroup/blkio-controller.txt
o Prefix all stats functions with blkio and make them static as applicable
o replace IO_TYPE_MAX with IO_TYPE_TOTAL
o Moved #define constant to top of blk-cgroup.c
o Pass dev_t around instead of char *
o Add note to documentation file about resetting stats
o use BLK_CGROUP_MODULE in addition to BLK_CGROUP config option in #ifdef
statements
o Avoid struct request specific knowledge in blk-cgroup. blk-cgroup.h now has
rq_direction() and rq_sync() functions which are used by CFQ and when using
io-controller at a higher level, bio_* functions can be added.
Signed-off-by: Divyesh Shah<dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 80010ef..b22e553 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -23,12 +23,31 @@
#define blkio_subsys_id blkio_subsys.subsys_id
#endif
-enum io_type {
- IO_READ = 0,
- IO_WRITE,
- IO_SYNC,
- IO_ASYNC,
- IO_TYPE_MAX
+enum stat_type {
+ /* Total time spent (in ns) between request dispatch to the driver and
+ * request completion for IOs doen by this cgroup. This may not be
+ * accurate when NCQ is turned on. */
+ BLKIO_STAT_SERVICE_TIME = 0,
+ /* Total bytes transferred */
+ BLKIO_STAT_SERVICE_BYTES,
+ /* Total IOs serviced, post merge */
+ BLKIO_STAT_SERVICED,
+ /* Total time spent waiting in scheduler queue in ns */
+ BLKIO_STAT_WAIT_TIME,
+ /* All the single valued stats go below this */
+ BLKIO_STAT_TIME,
+ BLKIO_STAT_SECTORS,
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ BLKIO_STAT_DEQUEUE
+#endif
+};
+
+enum stat_sub_type {
+ BLKIO_STAT_READ = 0,
+ BLKIO_STAT_WRITE,
+ BLKIO_STAT_SYNC,
+ BLKIO_STAT_ASYNC,
+ BLKIO_STAT_TOTAL
};
struct blkio_cgroup {
@@ -42,13 +61,7 @@
/* total disk time and nr sectors dispatched by this group */
uint64_t time;
uint64_t sectors;
- /* Total disk time used by IOs in ns */
- uint64_t io_service_time[IO_TYPE_MAX];
- uint64_t io_service_bytes[IO_TYPE_MAX]; /* Total bytes transferred */
- /* Total IOs serviced, post merge */
- uint64_t io_serviced[IO_TYPE_MAX];
- /* Total time spent waiting in scheduler queue in ns */
- uint64_t io_wait_time[IO_TYPE_MAX];
+ uint64_t stat_arr[BLKIO_STAT_WAIT_TIME + 1][BLKIO_STAT_TOTAL];
#ifdef CONFIG_DEBUG_BLK_CGROUP
/* How many times this group has been removed from service tree */
unsigned long dequeue;
@@ -65,7 +78,7 @@
char path[128];
#endif
/* The device MKDEV(major, minor), this group has been created for */
- dev_t dev;
+ dev_t dev;
/* Need to serialize the stats in the case of reset/update */
spinlock_t stats_lock;
@@ -128,21 +141,21 @@
extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
void *key);
+void blkio_group_init(struct blkio_group *blkg);
void blkiocg_update_timeslice_used(struct blkio_group *blkg,
unsigned long time);
-void blkiocg_update_request_dispatch_stats(struct blkio_group *blkg,
- struct request *rq);
-void blkiocg_update_request_completion_stats(struct blkio_group *blkg,
- struct request *rq);
+void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
+ bool direction, bool sync);
+void blkiocg_update_completion_stats(struct blkio_group *blkg,
+ uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
#else
struct cgroup;
static inline struct blkio_cgroup *
cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
+static inline void blkio_group_init(struct blkio_group *blkg) {}
static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key, dev_t dev)
-{
-}
+ struct blkio_group *blkg, void *key, dev_t dev) {}
static inline int
blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
@@ -151,9 +164,10 @@
blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
unsigned long time) {}
-static inline void blkiocg_update_request_dispatch_stats(
- struct blkio_group *blkg, struct request *rq) {}
-static inline void blkiocg_update_request_completion_stats(
- struct blkio_group *blkg, struct request *rq) {}
+static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+ uint64_t bytes, bool direction, bool sync) {}
+static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
+ uint64_t start_time, uint64_t io_start_time, bool direction,
+ bool sync) {}
#endif
#endif /* _BLK_CGROUP_H */