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/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt
index 630879c..ed04fe9 100644 (file)
--- a/Documentation/cgroups/blkio-controller.txt
+++ b/Documentation/cgroups/blkio-controller.txt
@@ -77,7 +77,6 @@ Details of cgroup files
 =======================
 - blkio.weight
        - Specifies per cgroup weight.
 =======================
 - blkio.weight
        - Specifies per cgroup weight.

-

          Currently allowed range of weights is from 100 to 1000.
 
 - blkio.time
          Currently allowed range of weights is from 100 to 1000.
 
 - blkio.time


@@ -92,6 +91,49 @@ Details of cgroup files
          third field specifies the number of sectors transferred by the
          group to/from the device.
 
          third field specifies the number of sectors transferred by the
          group to/from the device.
 

+- blkio.io_service_bytes
+       - Number of bytes transferred to/from the disk by the group. These
+         are further divided by the type of operation - read or write, sync
+         or async. First two fields specify the major and minor number of the
+         device, third field specifies the operation type and the fourth field
+         specifies the number of bytes.
+
+- blkio.io_serviced
+       - Number of IOs completed to/from the disk by the group. These
+         are further divided by the type of operation - read or write, sync
+         or async. First two fields specify the major and minor number of the
+         device, third field specifies the operation type and the fourth field
+         specifies the number of IOs.
+
+- blkio.io_service_time
+       - Total amount of time between request dispatch and request completion
+         for the IOs done by this cgroup. This is in nanoseconds to make it
+         meaningful for flash devices too. For devices with queue depth of 1,
+         this time represents the actual service time. When queue_depth > 1,
+         that is no longer true as requests may be served out of order. This
+         may cause the service time for a given IO to include the service time
+         of multiple IOs when served out of order which may result in total
+         io_service_time > actual time elapsed. This time is further divided by
+         the type of operation - read or write, sync or async. First two fields
+         specify the major and minor number of the device, third field
+         specifies the operation type and the fourth field specifies the
+         io_service_time in ns.
+
+- blkio.io_wait_time
+       - Total amount of time the IOs for this cgroup spent waiting in the
+         scheduler queues for service. This can be greater than the total time
+         elapsed since it is cumulative io_wait_time for all IOs. It is not a
+         measure of total time the cgroup spent waiting but rather a measure of
+         the wait_time for its individual IOs. For devices with queue_depth > 1
+         this metric does not include the time spent waiting for service once
+         the IO is dispatched to the device but till it actually gets serviced
+         (there might be a time lag here due to re-ordering of requests by the
+         device). This is in nanoseconds to make it meaningful for flash
+         devices too. This time is further divided by the type of operation -
+         read or write, sync or async. First two fields specify the major and
+         minor number of the device, third field specifies the operation type
+         and the fourth field specifies the io_wait_time in ns.
+

 - blkio.dequeue
        - Debugging aid only enabled if CONFIG_DEBUG_CFQ_IOSCHED=y. This
          gives the statistics about how many a times a group was dequeued
 - blkio.dequeue
        - Debugging aid only enabled if CONFIG_DEBUG_CFQ_IOSCHED=y. This
          gives the statistics about how many a times a group was dequeued


@@ -99,6 +141,10 @@ Details of cgroup files
          and minor number of the device and third field specifies the number
          of times a group was dequeued from a particular device.
 
          and minor number of the device and third field specifies the number
          of times a group was dequeued from a particular device.
 

+- blkio.reset_stats
+       - Writing an int to this file will result in resetting all the stats
+         for that cgroup.
+

 CFQ sysfs tunable
 =================
 /sys/block/<disk>/queue/iosched/group_isolation
 CFQ sysfs tunable
 =================
 /sys/block/<disk>/queue/iosched/group_isolation

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 9af7257..6797df5 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -18,6 +18,8 @@
 #include <linux/blkdev.h>
 #include "blk-cgroup.h"
 
 #include <linux/blkdev.h>
 #include "blk-cgroup.h"
 

+#define MAX_KEY_LEN 100
+

 static DEFINE_SPINLOCK(blkio_list_lock);
 static LIST_HEAD(blkio_list);
 
 static DEFINE_SPINLOCK(blkio_list_lock);
 static LIST_HEAD(blkio_list);
 


@@ -56,24 +58,27 @@ struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
 }
 EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
 
 }
 EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
 

+void blkio_group_init(struct blkio_group *blkg)
+{
+       spin_lock_init(&blkg->stats_lock);
+}
+EXPORT_SYMBOL_GPL(blkio_group_init);
+

 /*
  * Add to the appropriate stat variable depending on the request type.
  * This should be called with the blkg->stats_lock held.
  */
 /*
  * Add to the appropriate stat variable depending on the request type.
  * This should be called with the blkg->stats_lock held.
  */

-void io_add_stat(uint64_t *stat, uint64_t add, unsigned int flags)
+static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction,
+                               bool sync)

 {
 {

-       if (flags & REQ_RW)
-               stat[IO_WRITE] += add;
+       if (direction)
+               stat[BLKIO_STAT_WRITE] += add;

        else
        else

-               stat[IO_READ] += add;
-       /*
-        * Everywhere in the block layer, an IO is treated as sync if it is a
-        * read or a SYNC write. We follow the same norm.
-        */
-       if (!(flags & REQ_RW) || flags & REQ_RW_SYNC)
-               stat[IO_SYNC] += add;
+               stat[BLKIO_STAT_READ] += add;
+       if (sync)
+               stat[BLKIO_STAT_SYNC] += add;

        else
        else

-               stat[IO_ASYNC] += add;
+               stat[BLKIO_STAT_ASYNC] += add;

 }
 
 void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)
 }
 
 void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)


@@ -86,23 +91,25 @@ void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
 
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
 

-void blkiocg_update_request_dispatch_stats(struct blkio_group *blkg,
-                                               struct request *rq)
+void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+                               uint64_t bytes, bool direction, bool sync)

 {
        struct blkio_group_stats *stats;
        unsigned long flags;
 
        spin_lock_irqsave(&blkg->stats_lock, flags);
        stats = &blkg->stats;
 {
        struct blkio_group_stats *stats;
        unsigned long flags;
 
        spin_lock_irqsave(&blkg->stats_lock, flags);
        stats = &blkg->stats;

-       stats->sectors += blk_rq_sectors(rq);
-       io_add_stat(stats->io_serviced, 1, rq->cmd_flags);
-       io_add_stat(stats->io_service_bytes, blk_rq_sectors(rq) << 9,
-                       rq->cmd_flags);
+       stats->sectors += bytes >> 9;
+       blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction,
+                       sync);
+       blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes,
+                       direction, sync);

        spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
        spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }

+EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats);

 
 

-void blkiocg_update_request_completion_stats(struct blkio_group *blkg,
-                                               struct request *rq)
+void blkiocg_update_completion_stats(struct blkio_group *blkg,
+       uint64_t start_time, uint64_t io_start_time, bool direction, bool sync)

 {
        struct blkio_group_stats *stats;
        unsigned long flags;
 {
        struct blkio_group_stats *stats;
        unsigned long flags;


@@ -110,16 +117,15 @@ void blkiocg_update_request_completion_stats(struct blkio_group *blkg,
 
        spin_lock_irqsave(&blkg->stats_lock, flags);
        stats = &blkg->stats;
 
        spin_lock_irqsave(&blkg->stats_lock, flags);
        stats = &blkg->stats;

-       if (time_after64(now, rq->io_start_time_ns))
-               io_add_stat(stats->io_service_time, now - rq->io_start_time_ns,
-                               rq->cmd_flags);
-       if (time_after64(rq->io_start_time_ns, rq->start_time_ns))
-               io_add_stat(stats->io_wait_time,
-                               rq->io_start_time_ns - rq->start_time_ns,
-                               rq->cmd_flags);
+       if (time_after64(now, io_start_time))
+               blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME],
+                               now - io_start_time, direction, sync);
+       if (time_after64(io_start_time, start_time))
+               blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME],
+                               io_start_time - start_time, direction, sync);

        spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
        spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }

-EXPORT_SYMBOL_GPL(blkiocg_update_request_completion_stats);
+EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats);

 
 void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
                        struct blkio_group *blkg, void *key, dev_t dev)
 
 void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
                        struct blkio_group *blkg, void *key, dev_t dev)


@@ -230,7 +236,7 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
 }
 
 static int
 }
 
 static int

-blkiocg_reset_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
+blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)

 {
        struct blkio_cgroup *blkcg;
        struct blkio_group *blkg;
 {
        struct blkio_cgroup *blkcg;
        struct blkio_group *blkg;


@@ -249,29 +255,32 @@ blkiocg_reset_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
        return 0;
 }
 
        return 0;
 }
 

-void get_key_name(int type, char *disk_id, char *str, int chars_left)
+static void blkio_get_key_name(enum stat_sub_type type, dev_t dev, char *str,
+                               int chars_left, bool diskname_only)

 {
 {

-       strlcpy(str, disk_id, chars_left);
+       snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev));

        chars_left -= strlen(str);
        if (chars_left <= 0) {
                printk(KERN_WARNING
                        "Possibly incorrect cgroup stat display format");
                return;
        }
        chars_left -= strlen(str);
        if (chars_left <= 0) {
                printk(KERN_WARNING
                        "Possibly incorrect cgroup stat display format");
                return;
        }

+       if (diskname_only)
+               return;

        switch (type) {
        switch (type) {

-       case IO_READ:
+       case BLKIO_STAT_READ:

                strlcat(str, " Read", chars_left);
                break;
                strlcat(str, " Read", chars_left);
                break;

-       case IO_WRITE:
+       case BLKIO_STAT_WRITE:

                strlcat(str, " Write", chars_left);
                break;
                strlcat(str, " Write", chars_left);
                break;

-       case IO_SYNC:
+       case BLKIO_STAT_SYNC:

                strlcat(str, " Sync", chars_left);
                break;
                strlcat(str, " Sync", chars_left);
                break;

-       case IO_ASYNC:
+       case BLKIO_STAT_ASYNC:

                strlcat(str, " Async", chars_left);
                break;
                strlcat(str, " Async", chars_left);
                break;

-       case IO_TYPE_MAX:
+       case BLKIO_STAT_TOTAL:

                strlcat(str, " Total", chars_left);
                break;
        default:
                strlcat(str, " Total", chars_left);
                break;
        default:


@@ -279,63 +288,47 @@ void get_key_name(int type, char *disk_id, char *str, int chars_left)
        }
 }
 
        }
 }
 

-typedef uint64_t (get_var) (struct blkio_group *, int);
+static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val,
+                               struct cgroup_map_cb *cb, dev_t dev)
+{
+       blkio_get_key_name(0, dev, str, chars_left, true);
+       cb->fill(cb, str, val);
+       return val;
+}

 
 

-#define MAX_KEY_LEN 100
-uint64_t get_typed_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb,
-               get_var *getvar, char *disk_id)
+/* This should be called with blkg->stats_lock held */
+static uint64_t blkio_get_stat(struct blkio_group *blkg,
+               struct cgroup_map_cb *cb, dev_t dev, enum stat_type type)

 {
        uint64_t disk_total;
        char key_str[MAX_KEY_LEN];
 {
        uint64_t disk_total;
        char key_str[MAX_KEY_LEN];

-       int type;
+       enum stat_sub_type sub_type;
+
+       if (type == BLKIO_STAT_TIME)
+               return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
+                                       blkg->stats.time, cb, dev);
+       if (type == BLKIO_STAT_SECTORS)
+               return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
+                                       blkg->stats.sectors, cb, dev);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+       if (type == BLKIO_STAT_DEQUEUE)
+               return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
+                                       blkg->stats.dequeue, cb, dev);
+#endif

 
 

-       for (type = 0; type < IO_TYPE_MAX; type++) {
-               get_key_name(type, disk_id, key_str, MAX_KEY_LEN);
-               cb->fill(cb, key_str, getvar(blkg, type));
+       for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL;
+                       sub_type++) {
+               blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false);
+               cb->fill(cb, key_str, blkg->stats.stat_arr[type][sub_type]);

        }
        }

-       disk_total = getvar(blkg, IO_READ) + getvar(blkg, IO_WRITE);
-       get_key_name(IO_TYPE_MAX, disk_id, key_str, MAX_KEY_LEN);
+       disk_total = blkg->stats.stat_arr[type][BLKIO_STAT_READ] +
+                       blkg->stats.stat_arr[type][BLKIO_STAT_WRITE];
+       blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false);

        cb->fill(cb, key_str, disk_total);
        return disk_total;
 }
 
        cb->fill(cb, key_str, disk_total);
        return disk_total;
 }
 

-uint64_t get_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb,
-               get_var *getvar, char *disk_id)
-{
-       uint64_t var = getvar(blkg, 0);
-       cb->fill(cb, disk_id, var);
-       return var;
-}
-
-#define GET_STAT_INDEXED(__VAR)                                                \
-uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int type)                \
-{                                                                      \
-       return blkg->stats.__VAR[type];                                 \
-}                                                                      \
-
-GET_STAT_INDEXED(io_service_bytes);
-GET_STAT_INDEXED(io_serviced);
-GET_STAT_INDEXED(io_service_time);
-GET_STAT_INDEXED(io_wait_time);
-#undef GET_STAT_INDEXED
-
-#define GET_STAT(__VAR, __CONV)                                                \
-uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int dummy)       \
-{                                                                      \
-       uint64_t data = blkg->stats.__VAR;                              \
-       if (__CONV)                                                     \
-               data = (uint64_t)jiffies_to_msecs(data) * NSEC_PER_MSEC;\
-       return data;                                                    \
-}
-
-GET_STAT(time, 1);
-GET_STAT(sectors, 0);
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-GET_STAT(dequeue, 0);
-#endif
-#undef GET_STAT
-
-#define SHOW_FUNCTION_PER_GROUP(__VAR, get_stats, getvar, show_total)  \
+#define SHOW_FUNCTION_PER_GROUP(__VAR, type, show_total)               \

 static int blkiocg_##__VAR##_read(struct cgroup *cgroup,               \
                struct cftype *cftype, struct cgroup_map_cb *cb)        \
 {                                                                      \
 static int blkiocg_##__VAR##_read(struct cgroup *cgroup,               \
                struct cftype *cftype, struct cgroup_map_cb *cb)        \
 {                                                                      \


@@ -343,7 +336,6 @@ static int blkiocg_##__VAR##_read(struct cgroup *cgroup,            \
        struct blkio_group *blkg;                                       \
        struct hlist_node *n;                                           \
        uint64_t cgroup_total = 0;                                      \
        struct blkio_group *blkg;                                       \
        struct hlist_node *n;                                           \
        uint64_t cgroup_total = 0;                                      \

-       char disk_id[10];                                               \

                                                                        \
        if (!cgroup_lock_live_group(cgroup))                            \
                return -ENODEV;                                         \
                                                                        \
        if (!cgroup_lock_live_group(cgroup))                            \
                return -ENODEV;                                         \


@@ -353,10 +345,8 @@ static int blkiocg_##__VAR##_read(struct cgroup *cgroup,           \
        hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\
                if (blkg->dev) {                                        \
                        spin_lock_irq(&blkg->stats_lock);               \
        hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\
                if (blkg->dev) {                                        \
                        spin_lock_irq(&blkg->stats_lock);               \

-                       snprintf(disk_id, 10, "%u:%u", MAJOR(blkg->dev),\
-                                       MINOR(blkg->dev));              \
-                       cgroup_total += get_stats(blkg, cb, getvar,     \
-                                               disk_id);               \
+                       cgroup_total += blkio_get_stat(blkg, cb,        \
+                                               blkg->dev, type);       \

                        spin_unlock_irq(&blkg->stats_lock);             \
                }                                                       \
        }                                                               \
                        spin_unlock_irq(&blkg->stats_lock);             \
                }                                                       \
        }                                                               \


@@ -367,16 +357,14 @@ static int blkiocg_##__VAR##_read(struct cgroup *cgroup,          \
        return 0;                                                       \
 }
 
        return 0;                                                       \
 }
 

-SHOW_FUNCTION_PER_GROUP(time, get_stat, get_time_stat, 0);
-SHOW_FUNCTION_PER_GROUP(sectors, get_stat, get_sectors_stat, 0);
-SHOW_FUNCTION_PER_GROUP(io_service_bytes, get_typed_stat,
-                       get_io_service_bytes_stat, 1);
-SHOW_FUNCTION_PER_GROUP(io_serviced, get_typed_stat, get_io_serviced_stat, 1);
-SHOW_FUNCTION_PER_GROUP(io_service_time, get_typed_stat,
-                       get_io_service_time_stat, 1);
-SHOW_FUNCTION_PER_GROUP(io_wait_time, get_typed_stat, get_io_wait_time_stat, 1);
+SHOW_FUNCTION_PER_GROUP(time, BLKIO_STAT_TIME, 0);
+SHOW_FUNCTION_PER_GROUP(sectors, BLKIO_STAT_SECTORS, 0);
+SHOW_FUNCTION_PER_GROUP(io_service_bytes, BLKIO_STAT_SERVICE_BYTES, 1);
+SHOW_FUNCTION_PER_GROUP(io_serviced, BLKIO_STAT_SERVICED, 1);
+SHOW_FUNCTION_PER_GROUP(io_service_time, BLKIO_STAT_SERVICE_TIME, 1);
+SHOW_FUNCTION_PER_GROUP(io_wait_time, BLKIO_STAT_WAIT_TIME, 1);

 #ifdef CONFIG_DEBUG_BLK_CGROUP
 #ifdef CONFIG_DEBUG_BLK_CGROUP

-SHOW_FUNCTION_PER_GROUP(dequeue, get_stat, get_dequeue_stat, 0);
+SHOW_FUNCTION_PER_GROUP(dequeue, BLKIO_STAT_DEQUEUE, 0);

 #endif
 #undef SHOW_FUNCTION_PER_GROUP
 
 #endif
 #undef SHOW_FUNCTION_PER_GROUP
 


@@ -398,32 +386,30 @@ struct cftype blkio_files[] = {
        {
                .name = "time",
                .read_map = blkiocg_time_read,
        {
                .name = "time",
                .read_map = blkiocg_time_read,

-               .write_u64 = blkiocg_reset_write,

        },
        {
                .name = "sectors",
                .read_map = blkiocg_sectors_read,
        },
        {
                .name = "sectors",
                .read_map = blkiocg_sectors_read,

-               .write_u64 = blkiocg_reset_write,

        },
        {
                .name = "io_service_bytes",
                .read_map = blkiocg_io_service_bytes_read,
        },
        {
                .name = "io_service_bytes",
                .read_map = blkiocg_io_service_bytes_read,

-               .write_u64 = blkiocg_reset_write,

        },
        {
                .name = "io_serviced",
                .read_map = blkiocg_io_serviced_read,
        },
        {
                .name = "io_serviced",
                .read_map = blkiocg_io_serviced_read,

-               .write_u64 = blkiocg_reset_write,

        },
        {
                .name = "io_service_time",
                .read_map = blkiocg_io_service_time_read,
        },
        {
                .name = "io_service_time",
                .read_map = blkiocg_io_service_time_read,

-               .write_u64 = blkiocg_reset_write,

        },
        {
                .name = "io_wait_time",
                .read_map = blkiocg_io_wait_time_read,
        },
        {
                .name = "io_wait_time",
                .read_map = blkiocg_io_wait_time_read,

-               .write_u64 = blkiocg_reset_write,
+       },
+       {
+               .name = "reset_stats",
+               .write_u64 = blkiocg_reset_stats,

        },
 #ifdef CONFIG_DEBUG_BLK_CGROUP
        {
        },
 #ifdef CONFIG_DEBUG_BLK_CGROUP
        {

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 80010ef..b22e553 100644 (file)
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -23,12 +23,31 @@ extern struct cgroup_subsys blkio_subsys;
 #define blkio_subsys_id blkio_subsys.subsys_id
 #endif
 
 #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 {
 };
 
 struct blkio_cgroup {


@@ -42,13 +61,7 @@ struct blkio_group_stats {
        /* total disk time and nr sectors dispatched by this group */
        uint64_t time;
        uint64_t sectors;
        /* 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;
 #ifdef CONFIG_DEBUG_BLK_CGROUP
        /* How many times this group has been removed from service tree */
        unsigned long dequeue;


@@ -65,7 +78,7 @@ struct blkio_group {
        char path[128];
 #endif
        /* The device MKDEV(major, minor), this group has been created for */
        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;
 
        /* Need to serialize the stats in the case of reset/update */
        spinlock_t stats_lock;


@@ -128,21 +141,21 @@ extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
                                                void *key);
 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_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; }
 
 #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,
 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; }
 
 static inline int
 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }


@@ -151,9 +164,10 @@ static inline struct blkio_group *
 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) {}
 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 */
 #endif
 #endif /* _BLK_CGROUP_H */

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 42028e7..5617ae0 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -955,6 +955,7 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
        for_each_cfqg_st(cfqg, i, j, st)
                *st = CFQ_RB_ROOT;
        RB_CLEAR_NODE(&cfqg->rb_node);
        for_each_cfqg_st(cfqg, i, j, st)
                *st = CFQ_RB_ROOT;
        RB_CLEAR_NODE(&cfqg->rb_node);

+       blkio_group_init(&cfqg->blkg);

 
        /*
         * Take the initial reference that will be released on destroy
 
        /*
         * Take the initial reference that will be released on destroy


@@ -1865,7 +1866,8 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
        elv_dispatch_sort(q, rq);
 
        cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
        elv_dispatch_sort(q, rq);
 
        cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;

-       blkiocg_update_request_dispatch_stats(&cfqq->cfqg->blkg, rq);
+       blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq),
+                                       rq_data_dir(rq), rq_is_sync(rq));

 }
 
 /*
 }
 
 /*


@@ -3286,7 +3288,9 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
        WARN_ON(!cfqq->dispatched);
        cfqd->rq_in_driver--;
        cfqq->dispatched--;
        WARN_ON(!cfqq->dispatched);
        cfqd->rq_in_driver--;
        cfqq->dispatched--;

-       blkiocg_update_request_completion_stats(&cfqq->cfqg->blkg, rq);
+       blkiocg_update_completion_stats(&cfqq->cfqg->blkg, rq_start_time_ns(rq),
+                       rq_io_start_time_ns(rq), rq_data_dir(rq),
+                       rq_is_sync(rq));

 
        cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 
 
        cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f3fff8b..d483c49 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1209,9 +1209,27 @@ static inline void set_io_start_time_ns(struct request *req)
 {
        req->io_start_time_ns = sched_clock();
 }
 {
        req->io_start_time_ns = sched_clock();
 }

+
+static inline uint64_t rq_start_time_ns(struct request *req)
+{
+        return req->start_time_ns;
+}
+
+static inline uint64_t rq_io_start_time_ns(struct request *req)
+{
+        return req->io_start_time_ns;
+}

 #else
 static inline void set_start_time_ns(struct request *req) {}
 static inline void set_io_start_time_ns(struct request *req) {}
 #else
 static inline void set_start_time_ns(struct request *req) {}
 static inline void set_io_start_time_ns(struct request *req) {}

+static inline uint64_t rq_start_time_ns(struct request *req)
+{
+       return 0;
+}
+static inline uint64_t rq_io_start_time_ns(struct request *req)
+{
+       return 0;
+}

 #endif
 
 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
 #endif
 
 #define MODULE_ALIAS_BLOCKDEV(major,minor) \