From c4c76a05382c7d05e0b911daa58a827399e9ba1a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 8 Mar 2012 10:53:59 -0800 Subject: blkcg: restructure blkio_get_stat() Restructure blkio_get_stat() to prepare for removal of stats_lock. * Define BLKIO_STAT_ARR_NR explicitly to denote which stats have subtypes instead of using BLKIO_STAT_QUEUED. * Separate out stat acquisition and printing. After this, there are only two users of blkio_fill_stat(). Just open code it. * The code was mixing MAX_KEY_LEN and MAX_KEY_LEN - 1. There's no need to subtract one. Use MAX_KEY_LEN consistently. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 100 +++++++++++++++++++++++++++-------------------------- block/blk-cgroup.h | 6 +++- 2 files changed, 56 insertions(+), 50 deletions(-) (limited to 'block') diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 759bc58154c2..80887bc3a049 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -868,15 +868,6 @@ static void blkio_get_key_name(enum stat_sub_type type, const char *dname, } } -static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val, - struct cgroup_map_cb *cb, const char *dname) -{ - blkio_get_key_name(0, dname, str, chars_left, true); - cb->fill(cb, str, val); - return val; -} - - static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg, int plid, enum stat_type_cpu type, enum stat_sub_type sub_type) { @@ -916,8 +907,9 @@ static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg, int plid, if (type == BLKIO_STAT_CPU_SECTORS) { val = blkio_read_stat_cpu(blkg, plid, type, 0); - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, val, cb, - dname); + blkio_get_key_name(0, dname, key_str, MAX_KEY_LEN, true); + cb->fill(cb, key_str, val); + return val; } for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL; @@ -942,50 +934,60 @@ static uint64_t blkio_get_stat(struct blkio_group *blkg, int plid, struct cgroup_map_cb *cb, const char *dname, enum stat_type type) { - struct blkg_policy_data *pd = blkg->pd[plid]; - uint64_t disk_total; + struct blkio_group_stats *stats = &blkg->pd[plid]->stats; + uint64_t v = 0, disk_total = 0; char key_str[MAX_KEY_LEN]; - enum stat_sub_type sub_type; + int st; - if (type == BLKIO_STAT_TIME) - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, - pd->stats.time, cb, dname); + if (type >= BLKIO_STAT_ARR_NR) { + switch (type) { + case BLKIO_STAT_TIME: + v = stats->time; + break; #ifdef CONFIG_DEBUG_BLK_CGROUP - if (type == BLKIO_STAT_UNACCOUNTED_TIME) - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, - pd->stats.unaccounted_time, cb, dname); - if (type == BLKIO_STAT_AVG_QUEUE_SIZE) { - uint64_t sum = pd->stats.avg_queue_size_sum; - uint64_t samples = pd->stats.avg_queue_size_samples; - if (samples) - do_div(sum, samples); - else - sum = 0; - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, - sum, cb, dname); - } - if (type == BLKIO_STAT_GROUP_WAIT_TIME) - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, - pd->stats.group_wait_time, cb, dname); - if (type == BLKIO_STAT_IDLE_TIME) - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, - pd->stats.idle_time, cb, dname); - if (type == BLKIO_STAT_EMPTY_TIME) - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, - pd->stats.empty_time, cb, dname); - if (type == BLKIO_STAT_DEQUEUE) - return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, - pd->stats.dequeue, cb, dname); + case BLKIO_STAT_UNACCOUNTED_TIME: + v = stats->unaccounted_time; + break; + case BLKIO_STAT_AVG_QUEUE_SIZE: { + uint64_t samples = stats->avg_queue_size_samples; + + if (samples) { + v = stats->avg_queue_size_sum; + do_div(v, samples); + } + break; + } + case BLKIO_STAT_IDLE_TIME: + v = stats->idle_time; + break; + case BLKIO_STAT_EMPTY_TIME: + v = stats->empty_time; + break; + case BLKIO_STAT_DEQUEUE: + v = stats->dequeue; + break; + case BLKIO_STAT_GROUP_WAIT_TIME: + v = stats->group_wait_time; + break; #endif + default: + WARN_ON_ONCE(1); + } - for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL; - sub_type++) { - blkio_get_key_name(sub_type, dname, key_str, MAX_KEY_LEN, - false); - cb->fill(cb, key_str, pd->stats.stat_arr[type][sub_type]); + blkio_get_key_name(0, dname, key_str, MAX_KEY_LEN, true); + cb->fill(cb, key_str, v); + return v; } - disk_total = pd->stats.stat_arr[type][BLKIO_STAT_READ] + - pd->stats.stat_arr[type][BLKIO_STAT_WRITE]; + + for (st = BLKIO_STAT_READ; st < BLKIO_STAT_TOTAL; st++) { + v = stats->stat_arr[type][st]; + + blkio_get_key_name(st, dname, key_str, MAX_KEY_LEN, false); + cb->fill(cb, key_str, v); + if (st == BLKIO_STAT_READ || st == BLKIO_STAT_WRITE) + disk_total += v; + } + blkio_get_key_name(BLKIO_STAT_TOTAL, dname, key_str, MAX_KEY_LEN, false); cb->fill(cb, key_str, disk_total); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 1fa3c5e8d87f..8bdcf504f94b 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -39,6 +39,7 @@ enum stat_type { BLKIO_STAT_WAIT_TIME, /* Number of IOs queued up */ BLKIO_STAT_QUEUED, + /* All the single valued stats go below this */ BLKIO_STAT_TIME, #ifdef CONFIG_DEBUG_BLK_CGROUP @@ -52,6 +53,9 @@ enum stat_type { #endif }; +/* Types lower than this live in stat_arr and have subtypes */ +#define BLKIO_STAT_ARR_NR (BLKIO_STAT_QUEUED + 1) + /* Per cpu stats */ enum stat_type_cpu { BLKIO_STAT_CPU_SECTORS, @@ -117,7 +121,7 @@ struct blkio_cgroup { struct blkio_group_stats { /* total disk time and nr sectors dispatched by this group */ uint64_t time; - uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL]; + uint64_t stat_arr[BLKIO_STAT_ARR_NR][BLKIO_STAT_TOTAL]; #ifdef CONFIG_DEBUG_BLK_CGROUP /* Time not charged to this cgroup */ uint64_t unaccounted_time; -- cgit v1.2.3-59-g8ed1b