diff options
| -rw-r--r-- | Documentation/cgroups/blkio-controller.txt | 48 | ||||
| -rw-r--r-- | block/blk-cgroup.c | 190 | ||||
| -rw-r--r-- | block/blk-cgroup.h | 64 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 8 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 18 |
5 files changed, 198 insertions, 130 deletions
diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt index 630879cd9a4..ed04fe9cce1 100644 --- 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. - 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. +- 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 @@ -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. +- 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 diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 9af7257f429..6797df50882 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -18,6 +18,8 @@ #include <linux/blkdev.h> #include "blk-cgroup.h" +#define MAX_KEY_LEN 100 + 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); +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. */ -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 - 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 - stat[IO_ASYNC] += add; + stat[BLKIO_STAT_ASYNC] += add; } 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); -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; - 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); } +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; @@ -110,16 +117,15 @@ void blkiocg_update_request_completion_stats(struct blkio_group *blkg, 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); } -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) @@ -230,7 +236,7 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) } 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; @@ -249,29 +255,32 @@ blkiocg_reset_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) 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; } + if (diskname_only) + return; switch (type) { - case IO_READ: + case BLKIO_STAT_READ: strlcat(str, " Read", chars_left); break; - case IO_WRITE: + case BLKIO_STAT_WRITE: strlcat(str, " Write", chars_left); break; - case IO_SYNC: + case BLKIO_STAT_SYNC: strlcat(str, " Sync", chars_left); break; - case IO_ASYNC: + case BLKIO_STAT_ASYNC: strlcat(str, " Async", chars_left); break; - case IO_TYPE_MAX: + case BLKIO_STAT_TOTAL: 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]; - 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; } -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) \ { \ @@ -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; \ - char disk_id[10]; \ \ 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); \ - 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); \ } \ } \ @@ -367,16 +357,14 @@ static int blkiocg_##__VAR##_read(struct cgroup *cgroup, \ 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 -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 @@ -398,32 +386,30 @@ struct cftype blkio_files[] = { { .name = "time", .read_map = blkiocg_time_read, - .write_u64 = blkiocg_reset_write, }, { .name = "sectors", .read_map = blkiocg_sectors_read, - .write_u64 = blkiocg_reset_write, }, { .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, - .write_u64 = blkiocg_reset_write, }, { .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, - .write_u64 = blkiocg_reset_write, + }, + { + .name = "reset_stats", + .write_u64 = blkiocg_reset_stats, }, #ifdef CONFIG_DEBUG_BLK_CGROUP { diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 80010ef64ab..b22e55390a4 100644 --- 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 -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 @@ struct blkio_group_stats { /* 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 @@ struct blkio_group { 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 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); +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 @@ 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) {} -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 */ diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 42028e7128a..5617ae030b1 100644 --- 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); + blkio_group_init(&cfqg->blkg); /* * 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)]++; - 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--; - 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)]--; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f3fff8bf85e..d483c494672 100644 --- 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(); } + +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) {} +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) \ |