Merge branch 'master' into mjmac/DAOS-10028-pool

Change-Id: Id09db85bfe2f27ac91d2fdfd6f46935dc9011d47

src/engine/sched.c

@@ -1,5 +1,5 @@
 /**
- * (C) Copyright 2016-2023 Intel Corporation.
+ * (C) Copyright 2016-2024 Intel Corporation.
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -1188,11 +1188,16 @@ policy_fifo_enqueue(struct dss_xstream *dx, struct sched_request *req,
 
 	D_ASSERT(attr->sra_type < SCHED_REQ_TYPE_MAX);
 	/*
-	 * If @sra_enqueue_id is not zero, this is a resent RPC, it will
-	 * be inserted to sorted heap instead of fifo list.
+	 * The initial motivation behind this change is to utilize the heap
+	 * exclusively for sorted resent RPCs and the FIFO list for regular
+	 * fetch and update requests. This strategic allocation aims to avoid
+	 * potential performance impacts that could result from maintaining a
+	 * heap in the critical hot path.
 	 */
-	if (attr->sra_enqueue_id)
+	if (attr->sra_flags & SCHED_REQ_FL_RESENT) {
+		D_ASSERT(attr->sra_enqueue_id > 0);
 		return d_binheap_insert(&info->si_heap, &req->sr_node);
+	}
 
 	d_list_add_tail(&req->sr_link, &info->si_fifo_list);
 
@@ -1389,6 +1394,8 @@ sched_req_enqueue(struct dss_xstream *dx, struct sched_req_attr *attr,
 
 	if (attr->sra_enqueue_id == 0)
 		attr->sra_enqueue_id = ++info->si_cur_id;
+	else
+		attr->sra_flags |= SCHED_REQ_FL_RESENT;
 
 	/*
 	 * A RPC flow control mechanism is introduced to avoid RPC timeout when the

src/include/daos_srv/daos_engine.h

@@ -156,6 +156,7 @@ enum {
 	SCHED_REQ_FL_NO_DELAY	= (1 << 0),
 	SCHED_REQ_FL_PERIODIC	= (1 << 1),
 	SCHED_REQ_FL_NO_REJECT	= (1 << 2),
+	SCHED_REQ_FL_RESENT	= (1 << 3),
 };
 
 struct sched_req_attr {