[RFC PATCH 1/1] block: introduce activity based ioprio
From: zhaoyang.huang
Date: Wed Jan 17 2024 - 04:25:46 EST
From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
This commit try to introduce a feature which adjust the request ioprio
based on the folio's activity. The original idea comes from LRU_GEN
which provides more precised folio activity than before. This commit try
to adjust the request's ioprio when certain part of its folios are hot,
which indicate that this request carry important contents and need be
scheduled ealier.
This commit is tested via bellowing script[1] on a v6.6 android system and
get better iowait result[2] when mglru enabled, where
1. fault_latency.bin is an ebpf based test result which measure all task's
iowait latency when scheduled in/out.
2. costmem generate page fault by mmaping a file and access the VA.
3. dd generate concurrent vfs io.
[1]
/fault_latency.bin 1 5 > /data/dd_costmem &
costmem -c0 -a2048000 -b128000 -o0 1>/dev/null &
costmem -c0 -a2048000 -b128000 -o0 1>/dev/null &
costmem -c0 -a2048000 -b128000 -o0 1>/dev/null &
costmem -c0 -a2048000 -b128000 -o0 1>/dev/null &
dd if=/dev/block/sda of=/data/ddtest bs=1024 count=2048000 &
dd if=/dev/block/sda of=/data/ddtest1 bs=1024 count=2048000 &
dd if=/dev/block/sda of=/data/ddtest2 bs=1024 count=2048000 &
dd if=/dev/block/sda of=/data/ddtest3 bs=1024 count=2048000
[2]
mainline:
Summary for 5932.00(ms)
All Faults: 1398 235.67 counts/sec
Iowait: 553 93.22 counts/sec
All latency: 7432948 1253.03 us/ms
Iowait: 1321971 222.85 us/ms
Summary for 6706.00(ms)
All Faults: 1921 286.46 counts/sec
Iowait: 1273 189.83 counts/sec
All latency: 25890252 3860.76 us/ms
Iowait: 4468861 666.40 us/ms
Summary for 5838.00(ms)
All Faults: 1580 270.64 counts/sec
Iowait: 619 106.03 counts/sec
All latency: 6862215 1175.44 us/ms
Iowait: 1077616 184.59 us/ms
Summary for 5916.00(ms)
All Faults: 1195 201.99 counts/sec
Iowait: 494 83.50 counts/sec
All latency: 4555134 769.97 us/ms
Iowait: 902513 152.55 us/ms
Summary for 6229.00(ms)
All Faults: 1395 223.95 counts/sec
Iowait: 359 57.63 counts/sec
All latency: 6091882 977.99 us/ms
Iowait: 1251183 200.86 us/ms
Summary for 6059.00(ms)
All Faults: 1201 198.22 counts/sec
Iowait: 299 49.35 counts/sec
All latency: 5612143 926.25 us/ms
Iowait: 1155555 190.72 us/ms
Summary for 6005.00(ms)
All Faults: 847 141.05 counts/sec
Iowait: 320 53.29 counts/sec
All latency: 5852541 974.61 us/ms
Iowait: 433719 72.23 us/ms
Summary for 5895.00(ms)
All Faults: 1039 176.25 counts/sec
Iowait: 288 48.85 counts/sec
All latency: 4184680 709.87 us/ms
Iowait: 686266 116.41 us/ms
Summary for 6371.00(ms)
All Faults: 1176 184.59 counts/sec
Iowait: 269 42.22 counts/sec
All latency: 6282918 986.17 us/ms
Iowait: 1160952 182.22 us/ms
Summary for 6113.00(ms)
All Faults: 1322 216.26 counts/sec
Iowait: 281 45.97 counts/sec
All latency: 7208880 1179.27 us/ms
Iowait: 1336650 218.66 us/ms
commit:
Summary for 7225.00(ms)
All Faults: 1384 191.56 counts/sec
Iowait: 285 39.45 counts/sec
All latency: 6593081 912.54 us/ms
Iowait: 934041 129.28 us/ms
Summary for 6567.00(ms)
All Faults: 1378 209.84 counts/sec
Iowait: 167 25.43 counts/sec
All latency: 3761554 572.80 us/ms
Iowait: 220621 33.60 us/ms
Summary for 6118.00(ms)
All Faults: 1304 213.14 counts/sec
Iowait: 268 43.81 counts/sec
All latency: 3835332 626.89 us/ms
Iowait: 413900 67.65 us/ms
Summary for 6155.00(ms)
All Faults: 1177 191.23 counts/sec
Iowait: 185 30.06 counts/sec
All latency: 4839084 786.20 us/ms
Iowait: 660002 107.23 us/ms
Summary for 6448.00(ms)
All Faults: 1283 198.98 counts/sec
Iowait: 353 54.75 counts/sec
All latency: 4798334 744.16 us/ms
Iowait: 1258045 195.11 us/ms
Summary for 6179.00(ms)
All Faults: 1285 207.96 counts/sec
Iowait: 137 22.17 counts/sec
All latency: 3668456 593.70 us/ms
Iowait: 419731 67.93 us/ms
Summary for 6165.00(ms)
All Faults: 1500 243.31 counts/sec
Iowait: 182 29.52 counts/sec
All latency: 3357435 544.60 us/ms
Iowait: 279828 45.39 us/ms
Summary for 6270.00(ms)
All Faults: 1507 240.35 counts/sec
Iowait: 361 57.58 counts/sec
All latency: 4428320 706.27 us/ms
Iowait: 741304 118.23 us/ms
Summary for 6597.00(ms)
All Faults: 1263 191.45 counts/sec
Iowait: 238 36.08 counts/sec
All latency: 5115168 775.38 us/ms
Iowait: 950482 144.08 us/ms
Summary for 6503.00(ms)
All Faults: 1456 223.90 counts/sec
Iowait: 402 61.82 counts/sec
All latency: 6782757 1043.02 us/ms
Iowait: 1483803 228.17 us/ms
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
---
block/Kconfig.iosched | 7 +++++
block/mq-deadline.c | 70 +++++++++++++++++++++++++++++++++++--------
2 files changed, 64 insertions(+), 13 deletions(-)
diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 27f11320b8d1..cd6fcfca7782 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -44,4 +44,11 @@ config BFQ_CGROUP_DEBUG
Enable some debugging help. Currently it exports additional stat
files in a cgroup which can be useful for debugging.
+config ACTIVITY_BASED_IOPRIO
+ bool "Enable folio activity based ioprio on deadline"
+ depends on LRU_GEN && MQ_IOSCHED_DEADLINE
+ default n
+ help
+ This item enable the feature of adjust request's priority by
+ calculating its folio's activity.
endmenu
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index f958e79277b8..dfb43fff2ffe 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -15,6 +15,7 @@
#include <linux/compiler.h>
#include <linux/rbtree.h>
#include <linux/sbitmap.h>
+#include <linux/mm_inline.h>
#include <trace/events/block.h>
@@ -224,14 +225,42 @@ static void deadline_remove_request(struct request_queue *q,
q->last_merge = NULL;
}
+static enum dd_prio dd_req_ioprio(struct request *rq)
+{
+ enum dd_prio prio;
+ const u8 ioprio_class = dd_rq_ioclass(rq);
+#ifdef CONFIG_ACTIVITY_BASED_IOPRIO
+ struct bio *bio;
+ struct bio_vec bv;
+ struct bvec_iter iter;
+ struct page *page;
+ int gen = 0;
+ int cnt = 0;
+
+ if (req_op(rq) == REQ_OP_READ) {
+ __rq_for_each_bio(bio, rq) {
+ bio_for_each_bvec(bv, bio, iter) {
+ page = bv.bv_page;
+ gen += PageWorkingset(page) ? 1 : 0;
+ cnt++;
+ }
+ }
+ prio = (gen >= cnt / 2) ? ioprio_class_to_prio[IOPRIO_CLASS_RT] :
+ ioprio_class_to_prio[ioprio_class];
+ } else
+ prio = ioprio_class_to_prio[ioprio_class];
+#else
+ prio = ioprio_class_to_prio[ioprio_class];
+#endif
+ return prio;
+}
+
static void dd_request_merged(struct request_queue *q, struct request *req,
enum elv_merge type)
{
struct deadline_data *dd = q->elevator->elevator_data;
- const u8 ioprio_class = dd_rq_ioclass(req);
- const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+ const enum dd_prio prio = dd_req_ioprio(req);
struct dd_per_prio *per_prio = &dd->per_prio[prio];
-
/*
* if the merge was a front merge, we need to reposition request
*/
@@ -248,8 +277,7 @@ static void dd_merged_requests(struct request_queue *q, struct request *req,
struct request *next)
{
struct deadline_data *dd = q->elevator->elevator_data;
- const u8 ioprio_class = dd_rq_ioclass(next);
- const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+ const enum dd_prio prio = dd_req_ioprio(next);
lockdep_assert_held(&dd->lock);
@@ -745,10 +773,30 @@ static int dd_request_merge(struct request_queue *q, struct request **rq,
{
struct deadline_data *dd = q->elevator->elevator_data;
const u8 ioprio_class = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
- const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
- struct dd_per_prio *per_prio = &dd->per_prio[prio];
+ struct dd_per_prio *per_prio;
sector_t sector = bio_end_sector(bio);
struct request *__rq;
+#ifdef CONFIG_ACTIVITY_BASED_IOPRIO
+ enum dd_prio prio;
+ struct bio_vec bv;
+ struct bvec_iter iter;
+ struct page *page;
+ int gen = 0;
+ int cnt = 0;
+
+ if (bio_op(bio) == REQ_OP_READ) {
+ bio_for_each_bvec(bv, bio, iter) {
+ page = bv.bv_page;
+ gen += PageWorkingset(page) ? 1 : 0;
+ cnt++;
+ }
+ }
+ prio = (gen >= cnt / 2) ? ioprio_class_to_prio[IOPRIO_CLASS_RT] :
+ ioprio_class_to_prio[ioprio_class];
+#else
+ const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+#endif
+ per_prio = &dd->per_prio[prio];
if (!dd->front_merges)
return ELEVATOR_NO_MERGE;
@@ -798,10 +846,8 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
struct request_queue *q = hctx->queue;
struct deadline_data *dd = q->elevator->elevator_data;
const enum dd_data_dir data_dir = rq_data_dir(rq);
- u16 ioprio = req_get_ioprio(rq);
- u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio);
struct dd_per_prio *per_prio;
- enum dd_prio prio;
+ enum dd_prio prio = dd_req_ioprio(rq);
lockdep_assert_held(&dd->lock);
@@ -811,7 +857,6 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
*/
blk_req_zone_write_unlock(rq);
- prio = ioprio_class_to_prio[ioprio_class];
per_prio = &dd->per_prio[prio];
if (!rq->elv.priv[0]) {
per_prio->stats.inserted++;
@@ -920,8 +965,7 @@ static void dd_finish_request(struct request *rq)
{
struct request_queue *q = rq->q;
struct deadline_data *dd = q->elevator->elevator_data;
- const u8 ioprio_class = dd_rq_ioclass(rq);
- const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+ const enum dd_prio prio = dd_req_ioprio(rq);
struct dd_per_prio *per_prio = &dd->per_prio[prio];
/*
--
2.25.1