History

Merge tag 'block-5.14-2021-08-27' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe: - Revert the mq-deadline priority handling, it's causing serious performance regressions. While experimental patches exists to fix this up, it's too late to do so now. Revert it and re-do it properly for 5.15 instead. - Fix a NULL vs IS_ERR() regression in this release (Dan) - Fix a mq-deadline accounting regression in this release (Bart) - Mark cryptoloop as deprecated. It's broken and dm-crypt fully supports it, and it's actively intefering with loop. Plan on removal for 5.16 (Christoph) * tag 'block-5.14-2021-08-27' of git://git.kernel.dk/linux-block: cryptoloop: add a deprecation warning pd: fix a NULL vs IS_ERR() check Revert "block/mq-deadline: Prioritize high-priority requests" mq-deadline: Fix request accounting

Linus Torvalds committed 5 years ago

Commit 64b4fc42 parents 6f18b82 222013f4 files · +21 −45Browse files

Unified · Split

4 files
  1. block/mq-deadline.c +16 −42
  2. drivers/block/Kconfig +2 −2
  3. drivers/block/cryptoloop.c +2 −0
  4. drivers/block/paride/pd.c +1 −1
block/mq-deadline.c+16−42
@@ -31,11 +31,6 @@ · 30 unmodified lines
3131 */
3232 static const int read_expire = HZ / 2; /* max time before a read is submitted. */
3333 static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
34−/*
35− * Time after which to dispatch lower priority requests even if higher
36− * priority requests are pending.
37− */
38−static const int aging_expire = 10 * HZ;
3934 static const int writes_starved = 2; /* max times reads can starve a write */
4035 static const int fifo_batch = 16; /* # of sequential requests treated as one
4136 by the above parameters. For throughput. */
@@ -103,7 +98,6 @@ struct deadline_data { · 61 unmodified lines
10398 int writes_starved;
10499 int front_merges;
105100 u32 async_depth;
106− int aging_expire;
107101
108102 spinlock_t lock;
109103 spinlock_t zone_lock;
@@ -369,11 +363,10 @@ deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio, · 259 unmodified lines
369363
370364 /*
371365 * deadline_dispatch_requests selects the best request according to
372− * read/write expire, fifo_batch, etc and with a start time <= @latest.
366+ * read/write expire, fifo_batch, etc
373367 */
374368 static struct request *__dd_dispatch_request(struct deadline_data *dd,
375− struct dd_per_prio *per_prio,
376− u64 latest_start_ns)
369+ struct dd_per_prio *per_prio)
377370 {
378371 struct request *rq, *next_rq;
379372 enum dd_data_dir data_dir;
@@ -385,8 +378,6 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd, · 5 unmodified lines
385378 if (!list_empty(&per_prio->dispatch)) {
386379 rq = list_first_entry(&per_prio->dispatch, struct request,
387380 queuelist);
388− if (rq->start_time_ns > latest_start_ns)
389− return NULL;
390381 list_del_init(&rq->queuelist);
391382 goto done;
392383 }
@@ -464,8 +455,6 @@ dispatch_find_request: · 71 unmodified lines
464455 dd->batching = 0;
465456
466457 dispatch_request:
467− if (rq->start_time_ns > latest_start_ns)
468− return NULL;
469458 /*
470459 * rq is the selected appropriate request.
471460 */
@@ -494,32 +483,15 @@ done: · 22 unmodified lines
494483 static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
495484 {
496485 struct deadline_data *dd = hctx->queue->elevator->elevator_data;
497− const u64 now_ns = ktime_get_ns();
498− struct request *rq = NULL;
486+ struct request *rq;
499487 enum dd_prio prio;
500488
501489 spin_lock(&dd->lock);
502− /*
503− * Start with dispatching requests whose deadline expired more than
504− * aging_expire jiffies ago.
505− */
506− for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) {
507− rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns -
508− jiffies_to_nsecs(dd->aging_expire));
509− if (rq)
510− goto unlock;
511− }
512− /*
513− * Next, dispatch requests in priority order. Ignore lower priority
514− * requests if any higher priority requests are pending.
515− */
516490 for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
517− rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns);
518− if (rq || dd_queued(dd, prio))
491+ rq = __dd_dispatch_request(dd, &dd->per_prio[prio]);
492+ if (rq)
519493 break;
520494 }
521−
522−unlock:
523495 spin_unlock(&dd->lock);
524496
525497 return rq;
@@ -620,7 +592,6 @@ static int dd_init_sched(struct request_queue *q, struct elevator_type *e) · 94 unmodified lines
620592 dd->front_merges = 1;
621593 dd->last_dir = DD_WRITE;
622594 dd->fifo_batch = fifo_batch;
623− dd->aging_expire = aging_expire;
624595 spin_lock_init(&dd->lock);
625596 spin_lock_init(&dd->zone_lock);
626597
@@ -711,6 +682,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, · 84 unmodified lines
711682
712683 prio = ioprio_class_to_prio[ioprio_class];
713684 dd_count(dd, inserted, prio);
685+ rq->elv.priv[0] = (void *)(uintptr_t)1;
714686
715687 if (blk_mq_sched_try_insert_merge(q, rq, &free)) {
716688 blk_mq_free_requests(&free);
@@ -759,12 +731,10 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, · 42 unmodified lines
759731 spin_unlock(&dd->lock);
760732 }
761733
762−/*
763− * Nothing to do here. This is defined only to ensure that .finish_request
764− * method is called upon request completion.
765− */
734+/* Callback from inside blk_mq_rq_ctx_init(). */
766735 static void dd_prepare_request(struct request *rq)
767736 {
737+ rq->elv.priv[0] = NULL;
768738 }
769739
770740 /*
@@ -791,7 +761,14 @@ static void dd_finish_request(struct request *rq) · 20 unmodified lines
791761 const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
792762 struct dd_per_prio *per_prio = &dd->per_prio[prio];
793763
794− dd_count(dd, completed, prio);
764+ /*
765+ * The block layer core may call dd_finish_request() without having
766+ * called dd_insert_requests(). Hence only update statistics for
767+ * requests for which dd_insert_requests() has been called. See also
768+ * blk_mq_request_bypass_insert().
769+ */
770+ if (rq->elv.priv[0])
771+ dd_count(dd, completed, prio);
795772
796773 if (blk_queue_is_zoned(q)) {
797774 unsigned long flags;
@@ -836,7 +813,6 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \ · 38 unmodified lines
836813 #define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR))
837814 SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]);
838815 SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
839−SHOW_JIFFIES(deadline_aging_expire_show, dd->aging_expire);
840816 SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
841817 SHOW_INT(deadline_front_merges_show, dd->front_merges);
842818 SHOW_INT(deadline_async_depth_show, dd->front_merges);
@@ -866,7 +842,6 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) · 23 unmodified lines
866842 STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies)
867843 STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX);
868844 STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX);
869−STORE_JIFFIES(deadline_aging_expire_store, &dd->aging_expire, 0, INT_MAX);
870845 STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
871846 STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
872847 STORE_INT(deadline_async_depth_store, &dd->front_merges, 1, INT_MAX);
@@ -885,7 +860,6 @@ static struct elv_fs_entry deadline_attrs[] = { · 12 unmodified lines
885860 DD_ATTR(front_merges),
886861 DD_ATTR(async_depth),
887862 DD_ATTR(fifo_batch),
888− DD_ATTR(aging_expire),
889863 __ATTR_NULL
890864 };
891865
drivers/block/Kconfig+2−2
@@ -213,7 +213,7 @@ config BLK_DEV_LOOP_MIN_COUNT · 212 unmodified lines
213213 dynamically allocated with the /dev/loop-control interface.
214214
215215 config BLK_DEV_CRYPTOLOOP
216− tristate "Cryptoloop Support"
216+ tristate "Cryptoloop Support (DEPRECATED)"
217217 select CRYPTO
218218 select CRYPTO_CBC
219219 depends on BLK_DEV_LOOP
@@ -225,7 +225,7 @@ config BLK_DEV_CRYPTOLOOP · 5 unmodified lines
225225 WARNING: This device is not safe for journaled file systems like
226226 ext3 or Reiserfs. Please use the Device Mapper crypto module
227227 instead, which can be configured to be on-disk compatible with the
228− cryptoloop device.
228+ cryptoloop device. cryptoloop support will be removed in Linux 5.16.
229229
230230 source "drivers/block/drbd/Kconfig"
231231
drivers/block/cryptoloop.c+2−0
@@ -189,6 +189,8 @@ init_cryptoloop(void) · 188 unmodified lines
189189
190190 if (rc)
191191 printk(KERN_ERR "cryptoloop: loop_register_transfer failed\n");
192+ else
193+ pr_warn("the cryptoloop driver has been deprecated and will be removed in in Linux 5.16\n");
192194 return rc;
193195 }
194196
drivers/block/paride/pd.c+1−1
@@ -892,7 +892,7 @@ static void pd_probe_drive(struct pd_unit *disk) · 891 unmodified lines
892892 return;
893893
894894 p = blk_mq_alloc_disk(&disk->tag_set, disk);
895− if (!p) {
895+ if (IS_ERR(p)) {
896896 blk_mq_free_tag_set(&disk->tag_set);
897897 return;
898898 }