Mgerge remote-tracking branch 'torvalds/master' into perf/core

To sync headers, for instance, in this case tools/perf was ahead of
upstream till Linus merged tip/perf/core to get the
PERF_RECORD_TEXT_POKE changes:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
  diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 26 insertions, 15 deletions

diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 2e4ef51cdb32..b1acac518c4e 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -51,14 +51,6 @@ enum {
 	BLK_MQ_TAG_MAX		= BLK_MQ_NO_TAG - 1,
 };
 
-bool __blk_mq_get_driver_tag(struct request *rq);
-static inline bool blk_mq_get_driver_tag(struct request *rq)
-{
-	if (rq->tag != BLK_MQ_NO_TAG)
-		return true;
-	return __blk_mq_get_driver_tag(rq);
-}
-
 extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
 extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
 
@@ -79,15 +71,34 @@ static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
 }
 
 /*
- * This helper should only be used for flush request to share tag
- * with the request cloned from, and both the two requests can't be
- * in flight at the same time. The caller has to make sure the tag
- * can't be freed.
+ * For shared tag users, we track the number of currently active users
+ * and attempt to provide a fair share of the tag depth for each of them.
  */
-static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx,
-		unsigned int tag, struct request *rq)
+static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
+				  struct sbitmap_queue *bt)
 {
-	hctx->tags->rqs[tag] = rq;
+	unsigned int depth, users;
+
+	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED))
+		return true;
+	if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+		return true;
+
+	/*
+	 * Don't try dividing an ant
+	 */
+	if (bt->sb.depth == 1)
+		return true;
+
+	users = atomic_read(&hctx->tags->active_queues);
+	if (!users)
+		return true;
+
+	/*
+	 * Allow at least some tags
+	 */
+	depth = max((bt->sb.depth + users - 1) / users, 4U);
+	return atomic_read(&hctx->nr_active) < depth;
 }
 
 static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags,