leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

block: replace bio->bi_issue_stat with bio-specific type

Browse Source 
struct blk_issue_stat is going away, and bio->bi_issue_stat doesn't even
use the blk-stats interface, so we can provide a separate implementation
specific for bios. The helpers work the same way as the blk-stats
helpers.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Omar Sandoval 2018-05-09 02:08:49 -07:00 committed by Jens Axboe
parent a8a4594170
commit 5238dcf413
2 changed files with 56 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
block/blk-throttle.c
View File

@ -36,8 +36,6 @@ static int throtl_quantum = 32;
*/
#define LATENCY_FILTERED_HD (1000L) /* 1ms */
#define SKIP_LATENCY (((u64)1) << BLK_STAT_RES_SHIFT)
static struct blkcg_policy blkcg_policy_throtl;
/* A workqueue to queue throttle related work */
@ -2139,7 +2137,7 @@ static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio)
bio->bi_cg_private = tg;
blkg_get(tg_to_blkg(tg));
}
blk_stat_set_issue(&bio->bi_issue_stat, bio_sectors(bio));
bio_issue_init(&bio->bi_issue, bio_sectors(bio));
#endif
}
@ -2251,7 +2249,7 @@ out:
#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
if (throttled || !td->track_bio_latency)
bio->bi_issue_stat.stat |= SKIP_LATENCY;
bio->bi_issue.value |= BIO_ISSUE_THROTL_SKIP_LATENCY;
#endif
return throttled;
}
@ -2302,8 +2300,8 @@ void blk_throtl_bio_endio(struct bio *bio)
finish_time_ns = ktime_get_ns();
tg->last_finish_time = finish_time_ns >> 10;
start_time = blk_stat_time(&bio->bi_issue_stat) >> 10;
finish_time = __blk_stat_time(finish_time_ns) >> 10;
start_time = bio_issue_time(&bio->bi_issue) >> 10;
finish_time = __bio_issue_time(finish_time_ns) >> 10;
if (!start_time || finish_time <= start_time) {
blkg_put(tg_to_blkg(tg));
return;
@ -2311,16 +2309,15 @@ void blk_throtl_bio_endio(struct bio *bio)
lat = finish_time - start_time;
/* this is only for bio based driver */
if (!(bio->bi_issue_stat.stat & SKIP_LATENCY))
throtl_track_latency(tg->td, blk_stat_size(&bio->bi_issue_stat),
bio_op(bio), lat);
if (!(bio->bi_issue.value & BIO_ISSUE_THROTL_SKIP_LATENCY))
throtl_track_latency(tg->td, bio_issue_size(&bio->bi_issue),
bio_op(bio), lat);
if (tg->latency_target && lat >= tg->td->filtered_latency) {
int bucket;
unsigned int threshold;
bucket = request_bucket_index(
blk_stat_size(&bio->bi_issue_stat));
bucket = request_bucket_index(bio_issue_size(&bio->bi_issue));
threshold = tg->td->avg_buckets[rw][bucket].latency +
tg->latency_target;
if (lat > threshold)

49
include/linux/blk_types.h
View File

@ -8,6 +8,7 @@
#include <linux/types.h>
#include <linux/bvec.h>
#include <linux/ktime.h>
struct bio_set;
struct bio;
@ -94,6 +95,52 @@ struct blk_issue_stat {
u64 stat;
};
/*
* From most significant bit:
* 1 bit: reserved for other usage, see below
* 12 bits: original size of bio
* 51 bits: issue time of bio
*/
#define BIO_ISSUE_RES_BITS 1
#define BIO_ISSUE_SIZE_BITS 12
#define BIO_ISSUE_RES_SHIFT (64 - BIO_ISSUE_RES_BITS)
#define BIO_ISSUE_SIZE_SHIFT (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
#define BIO_ISSUE_TIME_MASK ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
#define BIO_ISSUE_SIZE_MASK \
(((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
#define BIO_ISSUE_RES_MASK (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
/* Reserved bit for blk-throtl */
#define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
struct bio_issue {
u64 value;
};
static inline u64 __bio_issue_time(u64 time)
{
return time & BIO_ISSUE_TIME_MASK;
}
static inline u64 bio_issue_time(struct bio_issue *issue)
{
return __bio_issue_time(issue->value);
}
static inline sector_t bio_issue_size(struct bio_issue *issue)
{
return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
}
static inline void bio_issue_init(struct bio_issue *issue,
sector_t size)
{
size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
(ktime_get_ns() & BIO_ISSUE_TIME_MASK) |
((u64)size << BIO_ISSUE_SIZE_SHIFT));
}
/*
* main unit of I/O for the block layer and lower layers (ie drivers and
* stacking drivers)
@ -138,7 +185,7 @@ struct bio {
struct cgroup_subsys_state *bi_css;
#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
void *bi_cg_private;
struct blk_issue_stat bi_issue_stat;
struct bio_issue bi_issue;
#endif
#endif
union {