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authorOmar Sandoval <osandov@fb.com>2018-05-09 12:08:49 +0300
committerJens Axboe <axboe@kernel.dk>2018-05-09 17:33:03 +0300
commit5238dcf4136fd7287be8e7d38752645bfa5782ec (patch)
tree9ae32c74428227bd647d35c6422246c14e228f81
parenta8a45941706bca05ef9234a17f5e4a50b9835a44 (diff)
downloadlinux-5238dcf4136fd7287be8e7d38752645bfa5782ec.tar.xz
block: replace bio->bi_issue_stat with bio-specific type
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>
-rw-r--r--block/blk-throttle.c19
-rw-r--r--include/linux/blk_types.h49
2 files changed, 56 insertions, 12 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index c5a131673733..35f9b8ff40d7 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -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)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 17b18b91ebac..b6f1d53cf113 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -8,6 +8,7 @@
#include <linux/types.h>
#include <linux/bvec.h>
+#include <linux/ktime.h>
struct bio_set;
struct bio;
@@ -95,6 +96,52 @@ struct blk_issue_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 {