diff options
Diffstat (limited to 'block/blk-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 995b58d46..df194bf93 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -10,6 +10,7 @@ #include <linux/blktrace_api.h> #include <linux/blk-mq.h> #include <linux/blk-cgroup.h> +#include <linux/wbt.h> #include "blk.h" #include "blk-mq.h" @@ -41,6 +42,19 @@ queue_var_store(unsigned long *var, const char *page, size_t count) return count; } +static ssize_t queue_var_store64(u64 *var, const char *page) +{ + int err; + u64 v; + + err = kstrtou64(page, 10, &v); + if (err < 0) + return err; + + *var = v; + return 0; +} + static ssize_t queue_requests_show(struct request_queue *q, char *page) { return queue_var_show(q->nr_requests, (page)); @@ -347,6 +361,110 @@ static ssize_t queue_poll_store(struct request_queue *q, const char *page, return ret; } +static ssize_t queue_wb_win_show(struct request_queue *q, char *page) +{ + if (!q->rq_wb) + return -EINVAL; + + return sprintf(page, "%llu\n", div_u64(q->rq_wb->win_nsec, 1000)); +} + +static ssize_t queue_wb_win_store(struct request_queue *q, const char *page, + size_t count) +{ + ssize_t ret; + u64 val; + + if (!q->rq_wb) + return -EINVAL; + + ret = queue_var_store64(&val, page); + if (ret < 0) + return ret; + + q->rq_wb->win_nsec = val * 1000ULL; + wbt_update_limits(q->rq_wb); + return count; +} + +static ssize_t queue_wb_lat_show(struct request_queue *q, char *page) +{ + if (!q->rq_wb) + return -EINVAL; + + return sprintf(page, "%llu\n", div_u64(q->rq_wb->min_lat_nsec, 1000)); +} + +static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page, + size_t count) +{ + ssize_t ret; + u64 val; + + if (!q->rq_wb) + return -EINVAL; + + ret = queue_var_store64(&val, page); + if (ret < 0) + return ret; + + q->rq_wb->min_lat_nsec = val * 1000ULL; + wbt_update_limits(q->rq_wb); + return count; +} + +static ssize_t queue_wc_show(struct request_queue *q, char *page) +{ + if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) + return sprintf(page, "write back\n"); + + return sprintf(page, "write through\n"); +} + +static ssize_t queue_wc_store(struct request_queue *q, const char *page, + size_t count) +{ + int set = -1; + + if (!strncmp(page, "write back", 10)) + set = 1; + else if (!strncmp(page, "write through", 13) || + !strncmp(page, "none", 4)) + set = 0; + + if (set == -1) + return -EINVAL; + + spin_lock_irq(q->queue_lock); + if (set) + queue_flag_set(QUEUE_FLAG_WC, q); + else + queue_flag_clear(QUEUE_FLAG_WC, q); + spin_unlock_irq(q->queue_lock); + + return count; +} + +static ssize_t print_stat(char *page, struct blk_rq_stat *stat, const char *pre) +{ + return sprintf(page, "%s samples=%llu, mean=%lld, min=%lld, max=%lld\n", + pre, (long long) stat->nr_samples, + (long long) stat->mean, (long long) stat->min, + (long long) stat->max); +} + +static ssize_t queue_stats_show(struct request_queue *q, char *page) +{ + struct blk_rq_stat stat[2]; + ssize_t ret; + + blk_queue_stat_get(q, stat); + + ret = print_stat(page, &stat[0], "read :"); + ret += print_stat(page + ret, &stat[1], "write:"); + return ret; +} + static struct queue_sysfs_entry queue_requests_entry = { .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, .show = queue_requests_show, @@ -478,6 +596,29 @@ static struct queue_sysfs_entry queue_poll_entry = { .store = queue_poll_store, }; +static struct queue_sysfs_entry queue_wc_entry = { + .attr = {.name = "write_cache", .mode = S_IRUGO | S_IWUSR }, + .show = queue_wc_show, + .store = queue_wc_store, +}; + +static struct queue_sysfs_entry queue_stats_entry = { + .attr = {.name = "stats", .mode = S_IRUGO }, + .show = queue_stats_show, +}; + +static struct queue_sysfs_entry queue_wb_lat_entry = { + .attr = {.name = "wbt_lat_usec", .mode = S_IRUGO | S_IWUSR }, + .show = queue_wb_lat_show, + .store = queue_wb_lat_store, +}; + +static struct queue_sysfs_entry queue_wb_win_entry = { + .attr = {.name = "wbt_window_usec", .mode = S_IRUGO | S_IWUSR }, + .show = queue_wb_win_show, + .store = queue_wb_win_store, +}; + static struct attribute *default_attrs[] = { &queue_requests_entry.attr, &queue_ra_entry.attr, @@ -503,6 +644,10 @@ static struct attribute *default_attrs[] = { &queue_iostats_entry.attr, &queue_random_entry.attr, &queue_poll_entry.attr, + &queue_wc_entry.attr, + &queue_stats_entry.attr, + &queue_wb_lat_entry.attr, + &queue_wb_win_entry.attr, NULL, }; @@ -617,6 +762,43 @@ struct kobj_type blk_queue_ktype = { .release = blk_release_queue, }; +static void blk_wb_stat_get(void *data, struct blk_rq_stat *stat) +{ + blk_queue_stat_get(data, stat); +} + +static void blk_wb_stat_clear(void *data) +{ + blk_stat_clear(data); +} + +static struct wb_stat_ops wb_stat_ops = { + .get = blk_wb_stat_get, + .clear = blk_wb_stat_clear, +}; + +static void blk_wb_init(struct request_queue *q) +{ + struct rq_wb *rwb; + + rwb = wbt_init(&q->backing_dev_info, &wb_stat_ops, q); + + /* + * If this fails, we don't get throttling + */ + if (IS_ERR(rwb)) + return; + + if (blk_queue_nonrot(q)) + rwb->min_lat_nsec = 2000000ULL; + else + rwb->min_lat_nsec = 75000000ULL; + + wbt_set_queue_depth(rwb, blk_queue_depth(q)); + wbt_set_write_cache(rwb, test_bit(QUEUE_FLAG_WC, &q->queue_flags)); + q->rq_wb = rwb; +} + int blk_register_queue(struct gendisk *disk) { int ret; @@ -656,6 +838,8 @@ int blk_register_queue(struct gendisk *disk) if (q->mq_ops) blk_mq_register_disk(disk); + blk_wb_init(q); + if (!q->request_fn) return 0; |