From 3e867f24cbe27478843c2f07cd1654e38b672bc2 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Wed, 21 Mar 2018 14:46:59 +0000
Subject: [PATCH] bufshutdown is no longer called with Giant held, so there's
 no need to drop or pickup Giant anymore. Remove that code and adjust
 comments.

---
 sys/kern/vfs_bio.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 092f4913abae..1e923cc9ea03 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -1376,25 +1376,20 @@ bufshutdown(int show_busybufs)
 
 #ifdef PREEMPTION
 		/*
-		 * Drop Giant and spin for a while to allow
-		 * interrupt threads to run.
+		 * Spin for a while to allow interrupt threads to run.
 		 */
-		DROP_GIANT();
 		DELAY(50000 * iter);
-		PICKUP_GIANT();
 #else
 		/*
-		 * Drop Giant and context switch several times to
-		 * allow interrupt threads to run.
+		 * Context switch several times to allow interrupt
+		 * threads to run.
 		 */
-		DROP_GIANT();
 		for (subiter = 0; subiter < 50 * iter; subiter++) {
 			thread_lock(curthread);
 			mi_switch(SW_VOL, NULL);
 			thread_unlock(curthread);
 			DELAY(1000);
 		}
-		PICKUP_GIANT();
 #endif
 	}
 	printf("\n");