# HG changeset patch
# User Joshua M. Clulow <josh@sysmgr.org>
# Date 1600750743 25200
# Node ID af8fee8a8d70584355ddc830711c8af4ef935aa8
# Parent  3757e6a94e621859167e45ab86d89101121354f2
13094 systems have more kmem caches than they used to
Reviewed by: Andy Fiddaman <andy@omniosce.org>
Reviewed by: Jason King <jason.brian.king@gmail.com>
Reviewed by: Peter Tribble <peter.tribble@gmail.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>

diff -r 3757e6a94e62 -r af8fee8a8d70 usr/src/uts/common/os/kmem.c
--- a/usr/src/uts/common/os/kmem.c	Mon Sep 21 21:58:47 2020 -0700
+++ b/usr/src/uts/common/os/kmem.c	Mon Sep 21 21:59:03 2020 -0700
@@ -23,6 +23,7 @@
  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  * Copyright 2018, Joyent, Inc.
+ * Copyright 2020 Oxide Computer Company
  */
 
 /*
@@ -4529,8 +4530,21 @@
 kmem_thread_init(void)
 {
 	kmem_move_init();
+
+	/*
+	 * This taskq is used for various kmem maintenance functions, including
+	 * kmem_reap().   When maintenance is required on every cache,
+	 * kmem_cache_applyall() dispatches one task per cache onto this queue.
+	 *
+	 * In the case of kmem_reap(), the system may be under increasingly
+	 * dire memory pressure and may not be able to allocate a new task
+	 * entry.  The count of entries to prepopulate (below) should cover at
+	 * least as many caches as we generally expect to exist on the system
+	 * so that they may all be scheduled for reaping under those
+	 * conditions.
+	 */
 	kmem_taskq = taskq_create_instance("kmem_taskq", 0, 1, minclsyspri,
-	    300, INT_MAX, TASKQ_PREPOPULATE);
+	    600, INT_MAX, TASKQ_PREPOPULATE);
 }
 
 void