From 4c1cc01cd834034963247faeea45682458da9924 Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Mon, 20 May 2002 17:54:48 +0000
Subject: [PATCH] In uma_zalloc_arg(), if we are performing a M_WAITOK
 allocation, ensure that td_intr_nesting_level is 0 (like malloc() does). 
 Since malloc() calls uma we can probably remove the check in malloc() for
 this now.  Also, perform an extra witness check in that case to make sure we
 don't hold any locks when performing a M_WAITOK allocation.

---
 sys/vm/uma_core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index df7966828980..c6924b0b7080 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -66,6 +66,7 @@
 #include <sys/lock.h>
 #include <sys/sysctl.h>
 #include <sys/mutex.h>
+#include <sys/proc.h>
 #include <sys/smp.h>
 #include <sys/vmmeter.h>
 
@@ -1317,6 +1318,12 @@ uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
 	printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
 #endif
 
+	if (!(flags & M_NOWAIT)) {
+		KASSERT(curthread->td_intr_nesting_level == 0,
+		   ("malloc(M_WAITOK) in interrupt context"));
+		WITNESS_SLEEP(1, NULL);
+	}
+
 zalloc_restart:
 	cpu = PCPU_GET(cpuid);
 	CPU_LOCK(zone, cpu);