@@ -830,6 +830,91 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
return 0;
}
+static const char *blk_wrr_name[BLK_WRR_COUNT] = {
+ [BLK_WRR_NONE] = "none",
+ [BLK_WRR_LOW] = "low",
+ [BLK_WRR_MEDIUM] = "medium",
+ [BLK_WRR_HIGH] = "high",
+ [BLK_WRR_URGENT] = "urgent",
+};
+
+static inline const char *blk_wrr_to_name(int wrr)
+{
+ if (wrr < BLK_WRR_NONE || wrr >= BLK_WRR_COUNT)
+ return "wrong";
+
+ return blk_wrr_name[wrr];
+}
+
+static ssize_t blkcg_wrr_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
+ struct gendisk *disk;
+ struct request_queue *q;
+ struct blkcg_gq *blkg;
+ unsigned int major, minor;
+ int wrr, key_len, part, ret;
+ char *body;
+
+ if (sscanf(buf, "%u:%u%n", &major, &minor, &key_len) != 2)
+ return -EINVAL;
+
+ body = buf + key_len;
+ if (!isspace(*body))
+ return -EINVAL;
+ body = skip_spaces(body);
+ wrr = sysfs_match_string(blk_wrr_name, body);
+ if (wrr == BLK_WRR_COUNT)
+ return -EINVAL;
+
+ disk = get_gendisk(MKDEV(major, minor), &part);
+ if (!disk)
+ return -ENODEV;
+ if (part) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ q = disk->queue;
+
+ blkg = blkg_lookup_create(blkcg, q);
+
+ atomic_set(&blkg->wrr, wrr);
+ put_disk_and_module(disk);
+
+ return nbytes;
+fail:
+ put_disk_and_module(disk);
+ return ret;
+}
+
+static int blkcg_wrr_show(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct blkcg_gq *blkg;
+
+ rcu_read_lock();
+
+ hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
+ const char *dname;
+ char *buf;
+ size_t size = seq_get_buf(sf, &buf), off = 0;
+
+ dname = blkg_dev_name(blkg);
+ if (!dname)
+ continue;
+
+ off += scnprintf(buf+off, size-off, "%s %s\n", dname,
+ blk_wrr_to_name(atomic_read(&blkg->wrr)));
+ seq_commit(sf, off);
+ }
+
+ rcu_read_unlock();
+ return 0;
+}
+
+
static struct cftype blkcg_files[] = {
{
.name = "stat",
@@ -844,6 +929,12 @@ static struct cftype blkcg_legacy_files[] = {
.name = "reset_stats",
.write_u64 = blkcg_reset_stats,
},
+ {
+ .name = "wrr",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .write = blkcg_wrr_write,
+ .seq_show = blkcg_wrr_show,
+ },
{ } /* terminate */
};
@@ -420,6 +420,10 @@ static int hctx_busy_show(void *data, struct seq_file *m)
static const char *const hctx_types[] = {
[HCTX_TYPE_DEFAULT] = "default",
[HCTX_TYPE_READ] = "read",
+ [HCTX_TYPE_WRR_LOW] = "wrr_low",
+ [HCTX_TYPE_WRR_MEDIUM] = "wrr_medium",
+ [HCTX_TYPE_WRR_HIGH] = "wrr_high",
+ [HCTX_TYPE_WRR_URGENT] = "wrr_urgent",
[HCTX_TYPE_POLL] = "poll",
};
@@ -7,6 +7,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/blk-mq.h>
+#include <linux/blk-cgroup.h>
#include <trace/events/block.h>
@@ -326,7 +327,9 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio,
{
struct elevator_queue *e = q->elevator;
struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
- struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, bio->bi_opf, ctx);
+ struct blkcg_gq *blkg = bio->bi_blkg;
+ int wrr = blkg ? atomic_read(&blkg->wrr) : BLK_WRR_NONE;
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, bio->bi_opf, ctx, wrr);
bool ret = false;
enum hctx_type type;
@@ -99,7 +99,7 @@ static int __blk_mq_get_tag(struct blk_mq_alloc_data *data,
return __sbitmap_queue_get(bt);
}
-unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
+unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data, int wrr)
{
struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
struct sbitmap_queue *bt;
@@ -159,7 +159,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
data->ctx = blk_mq_get_ctx(data->q);
data->hctx = blk_mq_map_queue(data->q, data->cmd_flags,
- data->ctx);
+ data->ctx, wrr);
tags = blk_mq_tags_from_data(data);
if (data->flags & BLK_MQ_REQ_RESERVED)
bt = &tags->breserved_tags;
@@ -25,7 +25,7 @@ struct blk_mq_tags {
extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy);
extern void blk_mq_free_tags(struct blk_mq_tags *tags);
-extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
+extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data, int wrr);
extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags,
struct blk_mq_ctx *ctx, unsigned int tag);
extern int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
@@ -340,6 +340,12 @@ static struct request *blk_mq_get_request(struct request_queue *q,
unsigned int tag;
bool clear_ctx_on_error = false;
u64 alloc_time_ns = 0;
+ int wrr;
+
+ if (bio && bio->bi_blkg)
+ wrr = atomic_read(&bio->bi_blkg->wrr);
+ else
+ wrr = BLK_WRR_NONE;
blk_queue_enter_live(q);
@@ -354,7 +360,7 @@ static struct request *blk_mq_get_request(struct request_queue *q,
}
if (likely(!data->hctx))
data->hctx = blk_mq_map_queue(q, data->cmd_flags,
- data->ctx);
+ data->ctx, wrr);
if (data->cmd_flags & REQ_NOWAIT)
data->flags |= BLK_MQ_REQ_NOWAIT;
@@ -374,7 +380,7 @@ static struct request *blk_mq_get_request(struct request_queue *q,
blk_mq_tag_busy(data->hctx);
}
- tag = blk_mq_get_tag(data);
+ tag = blk_mq_get_tag(data, wrr);
if (tag == BLK_MQ_TAG_FAIL) {
if (clear_ctx_on_error)
data->ctx = NULL;
@@ -1044,7 +1050,7 @@ bool blk_mq_get_driver_tag(struct request *rq)
data.flags |= BLK_MQ_REQ_RESERVED;
shared = blk_mq_tag_busy(data.hctx);
- rq->tag = blk_mq_get_tag(&data);
+ rq->tag = blk_mq_get_tag(&data, BLK_WRR_NONE);
if (rq->tag >= 0) {
if (shared) {
rq->rq_flags |= RQF_MQ_INFLIGHT;
@@ -101,7 +101,8 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *
*/
static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
unsigned int flags,
- struct blk_mq_ctx *ctx)
+ struct blk_mq_ctx *ctx,
+ int wrr)
{
enum hctx_type type = HCTX_TYPE_DEFAULT;
@@ -110,7 +111,22 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
*/
if (flags & REQ_HIPRI)
type = HCTX_TYPE_POLL;
- else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
+ else if (wrr > BLK_WRR_NONE && wrr < BLK_WRR_COUNT) {
+ switch (wrr) {
+ case BLK_WRR_LOW:
+ type = HCTX_TYPE_WRR_LOW;
+ break;
+ case BLK_WRR_MEDIUM:
+ type = HCTX_TYPE_WRR_MEDIUM;
+ break;
+ case BLK_WRR_HIGH:
+ type = HCTX_TYPE_WRR_HIGH;
+ break;
+ default:
+ type = HCTX_TYPE_WRR_URGENT;
+ break;
+ }
+ } else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
type = HCTX_TYPE_READ;
return ctx->hctxs[type];
@@ -40,7 +40,7 @@ extern struct ida blk_queue_ida;
static inline struct blk_flush_queue *
blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
{
- return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
+ return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx, BLK_WRR_NONE)->fq;
}
static inline void __blk_get_queue(struct request_queue *q)
@@ -138,6 +138,8 @@ struct blkcg_gq {
atomic64_t delay_start;
u64 last_delay;
int last_use;
+ /* weighted round robin */
+ atomic_t wrr;
struct rcu_head rcu_head;
};
@@ -193,17 +193,35 @@ struct blk_mq_queue_map {
* enum hctx_type - Type of hardware queue
* @HCTX_TYPE_DEFAULT: All I/O not otherwise accounted for.
* @HCTX_TYPE_READ: Just for READ I/O.
+ * @HCTX_TYPE_WRR_LOW: Weighted Round Robin low priority, when I/O is not polled.
+ * @HCTX_TYPE_WRR_MEDIUM: Weighted Round Robin medium priority, when I/O is not polled.
+ * @HCTX_TYPE_WRR_HIGH: Weighted Round Robin high priority, when I/O is not polled.
+ * @HCTX_TYPE_WRR_URGENT: Weighted Round Robin urgent priority, when I/O is not polled.
* @HCTX_TYPE_POLL: Polled I/O of any kind.
* @HCTX_MAX_TYPES: Number of types of hctx.
*/
enum hctx_type {
HCTX_TYPE_DEFAULT,
HCTX_TYPE_READ,
+ HCTX_TYPE_WRR_LOW,
+ HCTX_TYPE_WRR_MEDIUM,
+ HCTX_TYPE_WRR_HIGH,
+ HCTX_TYPE_WRR_URGENT,
HCTX_TYPE_POLL,
HCTX_MAX_TYPES,
};
+enum blk_wrr {
+ BLK_WRR_NONE,
+ BLK_WRR_LOW,
+ BLK_WRR_MEDIUM,
+ BLK_WRR_HIGH,
+ BLK_WRR_URGENT,
+
+ BLK_WRR_COUNT,
+};
+
/**
* struct blk_mq_tag_set - tag set that can be shared between request queues
* @map: One or more ctx -> hctx mappings. One map exists for each
Each block cgroup can select a weighted round robin type to make its io requests go to the specified haredware queue. Now we support four round robin type urgent, high, medium, low like what nvme specification dose. Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> --- block/blk-cgroup.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++ block/blk-mq-debugfs.c | 4 ++ block/blk-mq-sched.c | 5 ++- block/blk-mq-tag.c | 4 +- block/blk-mq-tag.h | 2 +- block/blk-mq.c | 12 ++++-- block/blk-mq.h | 20 +++++++++- block/blk.h | 2 +- include/linux/blk-cgroup.h | 2 + include/linux/blk-mq.h | 18 +++++++++ 10 files changed, 150 insertions(+), 10 deletions(-)