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-rw-r--r--block/blk-wbt.c129
1 files changed, 80 insertions, 49 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index f92fc84b5e2c..4f89b28fa652 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -29,6 +29,26 @@
#define CREATE_TRACE_POINTS
#include <trace/events/wbt.h>
+static inline void wbt_clear_state(struct request *rq)
+{
+ rq->wbt_flags = 0;
+}
+
+static inline enum wbt_flags wbt_flags(struct request *rq)
+{
+ return rq->wbt_flags;
+}
+
+static inline bool wbt_is_tracked(struct request *rq)
+{
+ return rq->wbt_flags & WBT_TRACKED;
+}
+
+static inline bool wbt_is_read(struct request *rq)
+{
+ return rq->wbt_flags & WBT_READ;
+}
+
enum {
/*
* Default setting, we'll scale up (to 75% of QD max) or down (min 1)
@@ -101,9 +121,15 @@ static bool wb_recent_wait(struct rq_wb *rwb)
return time_before(jiffies, wb->dirty_sleep + HZ);
}
-static inline struct rq_wait *get_rq_wait(struct rq_wb *rwb, bool is_kswapd)
+static inline struct rq_wait *get_rq_wait(struct rq_wb *rwb,
+ enum wbt_flags wb_acct)
{
- return &rwb->rq_wait[is_kswapd];
+ if (wb_acct & WBT_KSWAPD)
+ return &rwb->rq_wait[WBT_RWQ_KSWAPD];
+ else if (wb_acct & WBT_DISCARD)
+ return &rwb->rq_wait[WBT_RWQ_DISCARD];
+
+ return &rwb->rq_wait[WBT_RWQ_BG];
}
static void rwb_wake_all(struct rq_wb *rwb)
@@ -126,7 +152,7 @@ void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
if (!(wb_acct & WBT_TRACKED))
return;
- rqw = get_rq_wait(rwb, wb_acct & WBT_KSWAPD);
+ rqw = get_rq_wait(rwb, wb_acct);
inflight = atomic_dec_return(&rqw->inflight);
/*
@@ -139,10 +165,13 @@ void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
}
/*
- * If the device does write back caching, drop further down
- * before we wake people up.
+ * For discards, our limit is always the background. For writes, if
+ * the device does write back caching, drop further down before we
+ * wake people up.
*/
- if (rwb->wc && !wb_recent_wait(rwb))
+ if (wb_acct & WBT_DISCARD)
+ limit = rwb->wb_background;
+ else if (rwb->wc && !wb_recent_wait(rwb))
limit = 0;
else
limit = rwb->wb_normal;
@@ -165,24 +194,24 @@ void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
* Called on completion of a request. Note that it's also called when
* a request is merged, when the request gets freed.
*/
-void wbt_done(struct rq_wb *rwb, struct blk_issue_stat *stat)
+void wbt_done(struct rq_wb *rwb, struct request *rq)
{
if (!rwb)
return;
- if (!wbt_is_tracked(stat)) {
- if (rwb->sync_cookie == stat) {
+ if (!wbt_is_tracked(rq)) {
+ if (rwb->sync_cookie == rq) {
rwb->sync_issue = 0;
rwb->sync_cookie = NULL;
}
- if (wbt_is_read(stat))
+ if (wbt_is_read(rq))
wb_timestamp(rwb, &rwb->last_comp);
} else {
- WARN_ON_ONCE(stat == rwb->sync_cookie);
- __wbt_done(rwb, wbt_stat_to_mask(stat));
+ WARN_ON_ONCE(rq == rwb->sync_cookie);
+ __wbt_done(rwb, wbt_flags(rq));
}
- wbt_clear_state(stat);
+ wbt_clear_state(rq);
}
/*
@@ -479,6 +508,9 @@ static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
{
unsigned int limit;
+ if ((rw & REQ_OP_MASK) == REQ_OP_DISCARD)
+ return rwb->wb_background;
+
/*
* At this point we know it's a buffered write. If this is
* kswapd trying to free memory, or REQ_SYNC is set, then
@@ -529,11 +561,12 @@ static inline bool may_queue(struct rq_wb *rwb, struct rq_wait *rqw,
* Block if we will exceed our limit, or if we are currently waiting for
* the timer to kick off queuing again.
*/
-static void __wbt_wait(struct rq_wb *rwb, unsigned long rw, spinlock_t *lock)
+static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
+ unsigned long rw, spinlock_t *lock)
__releases(lock)
__acquires(lock)
{
- struct rq_wait *rqw = get_rq_wait(rwb, current_is_kswapd());
+ struct rq_wait *rqw = get_rq_wait(rwb, wb_acct);
DEFINE_WAIT(wait);
if (may_queue(rwb, rqw, &wait, rw))
@@ -559,21 +592,20 @@ static void __wbt_wait(struct rq_wb *rwb, unsigned long rw, spinlock_t *lock)
static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio)
{
- const int op = bio_op(bio);
-
- /*
- * If not a WRITE, do nothing
- */
- if (op != REQ_OP_WRITE)
- return false;
-
- /*
- * Don't throttle WRITE_ODIRECT
- */
- if ((bio->bi_opf & (REQ_SYNC | REQ_IDLE)) == (REQ_SYNC | REQ_IDLE))
+ switch (bio_op(bio)) {
+ case REQ_OP_WRITE:
+ /*
+ * Don't throttle WRITE_ODIRECT
+ */
+ if ((bio->bi_opf & (REQ_SYNC | REQ_IDLE)) ==
+ (REQ_SYNC | REQ_IDLE))
+ return false;
+ /* fallthrough */
+ case REQ_OP_DISCARD:
+ return true;
+ default:
return false;
-
- return true;
+ }
}
/*
@@ -584,7 +616,7 @@ static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio)
*/
enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio, spinlock_t *lock)
{
- unsigned int ret = 0;
+ enum wbt_flags ret = 0;
if (!rwb_enabled(rwb))
return 0;
@@ -598,41 +630,42 @@ enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio, spinlock_t *lock)
return ret;
}
- __wbt_wait(rwb, bio->bi_opf, lock);
+ if (current_is_kswapd())
+ ret |= WBT_KSWAPD;
+ if (bio_op(bio) == REQ_OP_DISCARD)
+ ret |= WBT_DISCARD;
+
+ __wbt_wait(rwb, ret, bio->bi_opf, lock);
if (!blk_stat_is_active(rwb->cb))
rwb_arm_timer(rwb);
- if (current_is_kswapd())
- ret |= WBT_KSWAPD;
-
return ret | WBT_TRACKED;
}
-void wbt_issue(struct rq_wb *rwb, struct blk_issue_stat *stat)
+void wbt_issue(struct rq_wb *rwb, struct request *rq)
{
if (!rwb_enabled(rwb))
return;
/*
- * Track sync issue, in case it takes a long time to complete. Allows
- * us to react quicker, if a sync IO takes a long time to complete.
- * Note that this is just a hint. 'stat' can go away when the
- * request completes, so it's important we never dereference it. We
- * only use the address to compare with, which is why we store the
- * sync_issue time locally.
+ * Track sync issue, in case it takes a long time to complete. Allows us
+ * to react quicker, if a sync IO takes a long time to complete. Note
+ * that this is just a hint. The request can go away when it completes,
+ * so it's important we never dereference it. We only use the address to
+ * compare with, which is why we store the sync_issue time locally.
*/
- if (wbt_is_read(stat) && !rwb->sync_issue) {
- rwb->sync_cookie = stat;
- rwb->sync_issue = blk_stat_time(stat);
+ if (wbt_is_read(rq) && !rwb->sync_issue) {
+ rwb->sync_cookie = rq;
+ rwb->sync_issue = rq->io_start_time_ns;
}
}
-void wbt_requeue(struct rq_wb *rwb, struct blk_issue_stat *stat)
+void wbt_requeue(struct rq_wb *rwb, struct request *rq)
{
if (!rwb_enabled(rwb))
return;
- if (stat == rwb->sync_cookie) {
+ if (rq == rwb->sync_cookie) {
rwb->sync_issue = 0;
rwb->sync_cookie = NULL;
}
@@ -701,7 +734,7 @@ static int wbt_data_dir(const struct request *rq)
if (op == REQ_OP_READ)
return READ;
- else if (op == REQ_OP_WRITE || op == REQ_OP_FLUSH)
+ else if (op_is_write(op))
return WRITE;
/* don't account */
@@ -713,8 +746,6 @@ int wbt_init(struct request_queue *q)
struct rq_wb *rwb;
int i;
- BUILD_BUG_ON(WBT_NR_BITS > BLK_STAT_RES_BITS);
-
rwb = kzalloc(sizeof(*rwb), GFP_KERNEL);
if (!rwb)
return -ENOMEM;