block: Add Maple I/O Scheduler
Signed-off-by: Joe Maples <joe@frap129.org>
This commit is contained in:
Joe Maples
BlackMesa123
parent
a9a7c24d76
commit
d90a42c430
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@ -115,6 +115,10 @@ config IOSCHED_BFQ
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a low latency to interactive and soft real-time applications.
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Details in Documentation/block/bfq-iosched.txt
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config IOSCHED_MAPLE
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tristate "Maple I/O scheduler"
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default n
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config BFQ_GROUP_IOSCHED
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bool "BFQ hierarchical scheduling support"
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depends on IOSCHED_BFQ && BLK_CGROUP
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@ -181,6 +185,9 @@ choice
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any workload. It also tries to guarantee low latency to
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interactive and soft real-time applications.
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config DEFAULT_MAPLE
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bool "Maple" if IOSCHED_MAPLE=y
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endchoice
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config DEFAULT_IOSCHED
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@ -197,6 +204,7 @@ config DEFAULT_IOSCHED
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default "zen" if DEFAULT_ZEN
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default "row" if DEFAULT_ROW
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default "bfq" if DEFAULT_BFQ
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default "maple" if DEFAULT_MAPLE
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endmenu
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@ -27,6 +27,7 @@ obj-$(CONFIG_IOSCHED_VR) += vr-iosched.o
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obj-$(CONFIG_IOSCHED_ZEN) += zen-iosched.o
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obj-$(CONFIG_IOSCHED_ROW) += row-iosched.o
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obj-$(CONFIG_IOSCHED_BFQ) += bfq-iosched.o
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obj-$(CONFIG_IOSCHED_MAPLE) += maple-iosched.o
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obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
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obj-$(CONFIG_BLK_CMDLINE_PARSER) += cmdline-parser.o
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426
block/maple-iosched.c
Normal file
426
block/maple-iosched.c
Normal file
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@ -0,0 +1,426 @@
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/*
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* Maple I/O Scheduler
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* Based on Zen and SIO.
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*
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* Copyright (C) 2016 Joe Maples <joe@frap129.org>
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* (C) 2012 Brandon Berhent <bbedward@gmail.com
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* (C) 2012 Miguel Boton <mboton@gmail.com>
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*
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* Maple uses a first come first serve style algorithm with seperated read/write
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* handling to allow for read biases. By prioritizing reads, simple tasks should improve
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* in performance. Maple also uses hooks for the powersuspend driver to increase
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* expirations when power is suspended to decrease workload.
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*/
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#include <linux/blkdev.h>
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#include <linux/elevator.h>
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#include <linux/bio.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/display_state.h>
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#define MAPLE_IOSCHED_PATCHLEVEL (8)
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enum { ASYNC, SYNC };
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/* Tunables */
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static const int sync_read_expire = 100; /* max time before a read sync is submitted. */
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static const int sync_write_expire = 350; /* max time before a write sync is submitted. */
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static const int async_read_expire = 200; /* ditto for read async, these limits are SOFT! */
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static const int async_write_expire = 500; /* ditto for write async, these limits are SOFT! */
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static const int fifo_batch = 16; /* # of sequential requests treated as one by the above parameters. */
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static const int writes_starved = 3; /* max times reads can starve a write */
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static const int sleep_latency_multiple = 5; /* multple for expire time when device is asleep */
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/* Elevator data */
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struct maple_data {
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/* Request queues */
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struct list_head fifo_list[2][2];
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/* Attributes */
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unsigned int batched;
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unsigned int starved;
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/* Settings */
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int fifo_expire[2][2];
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int fifo_batch;
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int writes_starved;
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int sleep_latency_multiple;
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};
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static inline struct maple_data *
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maple_get_data(struct request_queue *q) {
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return q->elevator->elevator_data;
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}
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static void
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maple_merged_requests(struct request_queue *q, struct request *rq,
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struct request *next)
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{
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/*
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* If next expires before rq, assign its expire time to rq
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* and move into next position (next will be deleted) in fifo.
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*/
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if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist)) {
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if (time_before(next->fifo_time, rq->fifo_time)) {
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list_move(&rq->queuelist, &next->queuelist);
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rq->fifo_time = next->fifo_time;
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}
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}
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/* Delete next request */
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rq_fifo_clear(next);
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}
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static void
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maple_add_request(struct request_queue *q, struct request *rq)
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{
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struct maple_data *mdata = maple_get_data(q);
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const int sync = rq_is_sync(rq);
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const int dir = rq_data_dir(rq);
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const bool display_on = is_display_on();
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/*
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* Add request to the proper fifo list and set its
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* expire time.
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*/
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/* inrease expiration when device is asleep */
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unsigned int fifo_expire_suspended = mdata->fifo_expire[sync][dir] * sleep_latency_multiple;
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if (display_on && mdata->fifo_expire[sync][dir]) {
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rq->fifo_time = jiffies + mdata->fifo_expire[sync][dir];
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list_add_tail(&rq->queuelist, &mdata->fifo_list[sync][dir]);
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} else if (!display_on && fifo_expire_suspended) {
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rq->fifo_time = jiffies + mdata->fifo_expire[sync][dir];
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list_add_tail(&rq->queuelist, &mdata->fifo_list[sync][dir]);
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}
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}
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static struct request *
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maple_expired_request(struct maple_data *mdata, int sync, int data_dir)
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{
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struct list_head *list = &mdata->fifo_list[sync][data_dir];
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struct request *rq;
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if (list_empty(list))
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return NULL;
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/* Retrieve request */
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rq = rq_entry_fifo(list->next);
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/* Request has expired */
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if (time_after(jiffies, rq->fifo_time))
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return rq;
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return NULL;
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}
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static struct request *
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maple_choose_expired_request(struct maple_data *mdata)
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{
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struct request *rq_sync_read = maple_expired_request(mdata, SYNC, READ);
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struct request *rq_sync_write = maple_expired_request(mdata, SYNC, WRITE);
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struct request *rq_async_read = maple_expired_request(mdata, ASYNC, READ);
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struct request *rq_async_write = maple_expired_request(mdata, ASYNC, WRITE);
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/* Reset (non-expired-)batch-counter */
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mdata->batched = 0;
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/*
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* Check expired requests.
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* Asynchronous requests have priority over synchronous.
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* Read requests have priority over write.
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*/
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if (rq_async_read && rq_sync_read) {
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if (time_after(rq_sync_read->fifo_time, rq_async_read->fifo_time))
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return rq_async_read;
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} else if (rq_async_read) {
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return rq_async_read;
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} else if (rq_sync_read) {
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return rq_sync_read;
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}
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if (rq_async_write && rq_sync_write) {
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if (time_after(rq_sync_write->fifo_time, rq_async_write->fifo_time))
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return rq_async_write;
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} else if (rq_async_write) {
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return rq_async_write;
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} else if (rq_sync_write) {
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return rq_sync_write;
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}
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return NULL;
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}
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static struct request *
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maple_choose_request(struct maple_data *mdata, int data_dir)
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{
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struct list_head *sync = mdata->fifo_list[SYNC];
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struct list_head *async = mdata->fifo_list[ASYNC];
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/* Increase (non-expired-)batch-counter */
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mdata->batched++;
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/*
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* Retrieve request from available fifo list.
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* Asynchronous requests have priority over synchronous.
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* Read requests have priority over write.
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*/
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if (!list_empty(&async[data_dir]))
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return rq_entry_fifo(async[data_dir].next);
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if (!list_empty(&sync[data_dir]))
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return rq_entry_fifo(sync[data_dir].next);
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if (!list_empty(&async[!data_dir]))
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return rq_entry_fifo(async[!data_dir].next);
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if (!list_empty(&sync[!data_dir]))
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return rq_entry_fifo(sync[!data_dir].next);
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return NULL;
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}
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static inline void
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maple_dispatch_request(struct maple_data *mdata, struct request *rq)
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{
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/*
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* Remove the request from the fifo list
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* and dispatch it.
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*/
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rq_fifo_clear(rq);
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elv_dispatch_add_tail(rq->q, rq);
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if (rq_data_dir(rq)) {
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mdata->starved = 0;
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} else {
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if (!list_empty(&mdata->fifo_list[SYNC][WRITE]) ||
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!list_empty(&mdata->fifo_list[ASYNC][WRITE]))
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mdata->starved++;
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}
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}
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static int
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maple_dispatch_requests(struct request_queue *q, int force)
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{
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struct maple_data *mdata = maple_get_data(q);
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struct request *rq = NULL;
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int data_dir = READ;
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const bool display_on = is_display_on();
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/*
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* Retrieve any expired request after a batch of
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* sequential requests.
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*/
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if (mdata->batched >= mdata->fifo_batch)
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rq = maple_choose_expired_request(mdata);
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/* Retrieve request */
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if (!rq) {
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/* Treat writes fairly while suspended, otherwise allow them to be starved */
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if (display_on && mdata->starved >= mdata->writes_starved)
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data_dir = WRITE;
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else if (!display_on && mdata->starved >= 1)
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data_dir = WRITE;
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rq = maple_choose_request(mdata, data_dir);
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if (!rq)
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return 0;
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}
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/* Dispatch request */
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maple_dispatch_request(mdata, rq);
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return 1;
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}
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static struct request *
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maple_former_request(struct request_queue *q, struct request *rq)
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{
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struct maple_data *mdata = maple_get_data(q);
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const int sync = rq_is_sync(rq);
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const int data_dir = rq_data_dir(rq);
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if (rq->queuelist.prev == &mdata->fifo_list[sync][data_dir])
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return NULL;
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/* Return former request */
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return list_entry(rq->queuelist.prev, struct request, queuelist);
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}
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static struct request *
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maple_latter_request(struct request_queue *q, struct request *rq)
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{
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struct maple_data *mdata = maple_get_data(q);
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const int sync = rq_is_sync(rq);
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const int data_dir = rq_data_dir(rq);
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if (rq->queuelist.next == &mdata->fifo_list[sync][data_dir])
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return NULL;
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/* Return latter request */
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return list_entry(rq->queuelist.next, struct request, queuelist);
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}
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static int maple_init_queue(struct request_queue *q, struct elevator_type *e)
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{
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struct maple_data *mdata;
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struct elevator_queue *eq;
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eq = elevator_alloc(q, e);
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if (!eq)
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return -ENOMEM;
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/* Allocate structure */
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mdata = kmalloc_node(sizeof(*mdata), GFP_KERNEL, q->node);
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if (!mdata) {
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kobject_put(&eq->kobj);
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return -ENOMEM;
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}
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eq->elevator_data = mdata;
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/* Initialize fifo lists */
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INIT_LIST_HEAD(&mdata->fifo_list[SYNC][READ]);
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INIT_LIST_HEAD(&mdata->fifo_list[SYNC][WRITE]);
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INIT_LIST_HEAD(&mdata->fifo_list[ASYNC][READ]);
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INIT_LIST_HEAD(&mdata->fifo_list[ASYNC][WRITE]);
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/* Initialize data */
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mdata->batched = 0;
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mdata->fifo_expire[SYNC][READ] = sync_read_expire;
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mdata->fifo_expire[SYNC][WRITE] = sync_write_expire;
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mdata->fifo_expire[ASYNC][READ] = async_read_expire;
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mdata->fifo_expire[ASYNC][WRITE] = async_write_expire;
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mdata->fifo_batch = fifo_batch;
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mdata->writes_starved = writes_starved;
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mdata->sleep_latency_multiple = sleep_latency_multiple;
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spin_lock_irq(q->queue_lock);
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q->elevator = eq;
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spin_unlock_irq(q->queue_lock);
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return 0;
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}
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static void
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maple_exit_queue(struct elevator_queue *e)
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{
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struct maple_data *mdata = e->elevator_data;
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/* Free structure */
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kfree(mdata);
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}
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/*
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* sysfs code
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*/
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static ssize_t
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maple_var_show(int var, char *page)
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{
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return sprintf(page, "%d\n", var);
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}
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static ssize_t
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maple_var_store(int *var, const char *page, size_t count)
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{
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char *p = (char *) page;
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*var = simple_strtol(p, &p, 10);
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return count;
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}
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#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
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static ssize_t __FUNC(struct elevator_queue *e, char *page) \
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{ \
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struct maple_data *mdata = e->elevator_data; \
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int __data = __VAR; \
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if (__CONV) \
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__data = jiffies_to_msecs(__data); \
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return maple_var_show(__data, (page)); \
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}
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SHOW_FUNCTION(maple_sync_read_expire_show, mdata->fifo_expire[SYNC][READ], 1);
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SHOW_FUNCTION(maple_sync_write_expire_show, mdata->fifo_expire[SYNC][WRITE], 1);
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SHOW_FUNCTION(maple_async_read_expire_show, mdata->fifo_expire[ASYNC][READ], 1);
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SHOW_FUNCTION(maple_async_write_expire_show, mdata->fifo_expire[ASYNC][WRITE], 1);
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SHOW_FUNCTION(maple_fifo_batch_show, mdata->fifo_batch, 0);
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SHOW_FUNCTION(maple_writes_starved_show, mdata->writes_starved, 0);
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SHOW_FUNCTION(maple_sleep_latency_multiple_show, mdata->sleep_latency_multiple, 0);
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#undef SHOW_FUNCTION
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#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
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static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
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{ \
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struct maple_data *mdata = e->elevator_data; \
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int __data; \
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int ret = maple_var_store(&__data, (page), count); \
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if (__data < (MIN)) \
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__data = (MIN); \
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else if (__data > (MAX)) \
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__data = (MAX); \
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if (__CONV) \
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*(__PTR) = msecs_to_jiffies(__data); \
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else \
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*(__PTR) = __data; \
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return ret; \
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}
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STORE_FUNCTION(maple_sync_read_expire_store, &mdata->fifo_expire[SYNC][READ], 0, INT_MAX, 1);
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STORE_FUNCTION(maple_sync_write_expire_store, &mdata->fifo_expire[SYNC][WRITE], 0, INT_MAX, 1);
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STORE_FUNCTION(maple_async_read_expire_store, &mdata->fifo_expire[ASYNC][READ], 0, INT_MAX, 1);
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STORE_FUNCTION(maple_async_write_expire_store, &mdata->fifo_expire[ASYNC][WRITE], 0, INT_MAX, 1);
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STORE_FUNCTION(maple_fifo_batch_store, &mdata->fifo_batch, 1, INT_MAX, 0);
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STORE_FUNCTION(maple_writes_starved_store, &mdata->writes_starved, 1, INT_MAX, 0);
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STORE_FUNCTION(maple_sleep_latency_multiple_store, &mdata->sleep_latency_multiple, 1, INT_MAX, 0);
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#undef STORE_FUNCTION
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#define DD_ATTR(name) \
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__ATTR(name, S_IRUGO|S_IWUSR, maple_##name##_show, \
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maple_##name##_store)
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static struct elv_fs_entry maple_attrs[] = {
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DD_ATTR(sync_read_expire),
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DD_ATTR(sync_write_expire),
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DD_ATTR(async_read_expire),
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DD_ATTR(async_write_expire),
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DD_ATTR(fifo_batch),
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DD_ATTR(writes_starved),
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DD_ATTR(sleep_latency_multiple),
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__ATTR_NULL
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};
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static struct elevator_type iosched_maple = {
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.ops = {
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.elevator_merge_req_fn = maple_merged_requests,
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.elevator_dispatch_fn = maple_dispatch_requests,
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.elevator_add_req_fn = maple_add_request,
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.elevator_former_req_fn = maple_former_request,
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.elevator_latter_req_fn = maple_latter_request,
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.elevator_init_fn = maple_init_queue,
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.elevator_exit_fn = maple_exit_queue,
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},
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.elevator_attrs = maple_attrs,
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.elevator_name = "maple",
|
||||
.elevator_owner = THIS_MODULE,
|
||||
};
|
||||
|
||||
static int __init maple_init(void)
|
||||
{
|
||||
/* Register elevator */
|
||||
elv_register(&iosched_maple);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void __exit maple_exit(void)
|
||||
{
|
||||
/* Unregister elevator */
|
||||
elv_unregister(&iosched_maple);
|
||||
}
|
||||
|
||||
module_init(maple_init);
|
||||
module_exit(maple_exit);
|
||||
|
||||
MODULE_AUTHOR("Joe Maples");
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_DESCRIPTION("Maple I/O Scheduler");
|
||||
MODULE_VERSION("1.0");
|
||||
Loading…
Reference in New Issue
Block a user