Patch adds an association between iocontext ioprio and the ioprio of a request. This feature is only enabled if a queue flag is set to indicate that requests should have ioprio associated with them. The queue flag is exposed as the req_prio queue sysfs entry.
Signed-off-by: Adam Mananzanares <[email protected]> --- Documentation/block/queue-sysfs.txt | 12 ++++++++++++ block/blk-core.c | 5 +++++ block/blk-sysfs.c | 32 ++++++++++++++++++++++++++++++++ include/linux/blkdev.h | 3 +++ 4 files changed, 52 insertions(+) diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index 2a39040..3ca4e8f 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -144,6 +144,18 @@ For storage configurations that need to maximize distribution of completion processing setting this option to '2' forces the completion to run on the requesting cpu (bypassing the "group" aggregation logic). +rq_ioc_prio (RW) +---------------- +If this option is '1', and there is a valid iocontext associated with the +issuing context, and the bio we are processing does not have a valid +prio, then we save the prio value from the iocontext with the request. + +This feature can be combined with device drivers that are aware of prio +values in order to handle prio accordingly. An example would be if the ata +layer recognizes prio and creates ata commands with high priority and sends +them to the device. If the hardware supports priorities for commands then +this has the potential to speed up response times for high priority IO. + scheduler (RW) -------------- When read, this file will display the current and available IO schedulers diff --git a/block/blk-core.c b/block/blk-core.c index 14d7c07..2e740c4 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -33,6 +33,7 @@ #include <linux/ratelimit.h> #include <linux/pm_runtime.h> #include <linux/blk-cgroup.h> +#include <linux/ioprio.h> #define CREATE_TRACE_POINTS #include <trace/events/block.h> @@ -1648,6 +1649,7 @@ unsigned int blk_plug_queued_count(struct request_queue *q) void init_request_from_bio(struct request *req, struct bio *bio) { + struct io_context *ioc = rq_ioc(bio); req->cmd_type = REQ_TYPE_FS; req->cmd_flags |= bio->bi_opf & REQ_COMMON_MASK; @@ -1657,6 +1659,9 @@ void init_request_from_bio(struct request *req, struct bio *bio) req->errors = 0; req->__sector = bio->bi_iter.bi_sector; req->ioprio = bio_prio(bio); + if (blk_queue_rq_ioc_prio(req->q) && !ioprio_valid(req->ioprio) && ioc) + req->ioprio = ioc->ioprio; + blk_rq_bio_prep(req->q, req, bio); } diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 9cc8d7c..a9c5105 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -384,6 +384,31 @@ static ssize_t queue_dax_show(struct request_queue *q, char *page) return queue_var_show(blk_queue_dax(q), page); } +static ssize_t queue_rq_ioc_prio_show(struct request_queue *q, char *page) +{ + return queue_var_show(blk_queue_rq_ioc_prio(q), page); +} + +static ssize_t queue_rq_ioc_prio_store(struct request_queue *q, + const char *page, size_t count) +{ + unsigned long rq_ioc_prio_on; + ssize_t ret; + + ret = queue_var_store(&rq_ioc_prio_on, page, count); + if (ret < 0) + return ret; + + spin_lock_irq(q->queue_lock); + if (rq_ioc_prio_on) + queue_flag_set(QUEUE_FLAG_RQ_IOC_PRIO, q); + else + queue_flag_clear(QUEUE_FLAG_RQ_IOC_PRIO, q); + spin_unlock_irq(q->queue_lock); + + return ret; +} + static struct queue_sysfs_entry queue_requests_entry = { .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, .show = queue_requests_show, @@ -526,6 +551,12 @@ static struct queue_sysfs_entry queue_dax_entry = { .show = queue_dax_show, }; +static struct queue_sysfs_entry queue_rq_ioc_prio_entry = { + .attr = {.name = "rq_ioc_prio", .mode = S_IRUGO | S_IWUSR }, + .show = queue_rq_ioc_prio_show, + .store = queue_rq_ioc_prio_store, +}; + static struct attribute *default_attrs[] = { &queue_requests_entry.attr, &queue_ra_entry.attr, @@ -553,6 +584,7 @@ static struct attribute *default_attrs[] = { &queue_poll_entry.attr, &queue_wc_entry.attr, &queue_dax_entry.attr, + &queue_rq_ioc_prio_entry.attr, NULL, }; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c47c358..63b842a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -505,6 +505,7 @@ struct request_queue { #define QUEUE_FLAG_FUA 24 /* device supports FUA writes */ #define QUEUE_FLAG_FLUSH_NQ 25 /* flush not queueuable */ #define QUEUE_FLAG_DAX 26 /* device supports DAX */ +#define QUEUE_FLAG_RQ_IOC_PRIO 27 /* Use iocontext ioprio */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ @@ -595,6 +596,8 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) #define blk_queue_secure_erase(q) \ (test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags)) #define blk_queue_dax(q) test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags) +#define blk_queue_rq_ioc_prio(q) \ + test_bit(QUEUE_FLAG_RQ_IOC_PRIO, &(q)->queue_flags) #define blk_noretry_request(rq) \ ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
