From fad44deea3b6e4a0ceb8a25ba411a220337d3f15 Mon Sep 17 00:00:00 2001
From: Alan Cox <alc@FreeBSD.org>
Date: Tue, 10 Aug 2004 21:47:11 +0000
Subject: [PATCH] Eliminate the acquisition and release of Giant within
 physio().  Remove the spl calls.

Reviewed by: phk@
Discussed with: scottl@
---
 sys/kern/kern_physio.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/sys/kern/kern_physio.c b/sys/kern/kern_physio.c
index c2c9b3f198b9..803995c0380b 100644
--- a/sys/kern/kern_physio.c
+++ b/sys/kern/kern_physio.c
@@ -36,13 +36,10 @@ physio(struct cdev *dev, struct uio *uio, int ioflag)
 {
 	int i;
 	int error;
-	int spl;
 	caddr_t sa;
 	u_int iolen;
 	struct buf *bp;
 
-	/* We cannot trust the device driver to hold Giant for us */
-	mtx_lock(&Giant);
 	/* Keep the process UPAGES from being swapped. XXX: why ? */
 	PHOLD(curproc);
 
@@ -99,12 +96,10 @@ physio(struct cdev *dev, struct uio *uio, int ioflag)
 				}
 
 			DEV_STRATEGY(bp);
-			spl = splbio();
 			if (uio->uio_rw == UIO_READ)
 				bwait(bp, PRIBIO, "physrd");
 			else
 				bwait(bp, PRIBIO, "physwr");
-			splx(spl);
 
 			if (uio->uio_segflg == UIO_USERSPACE)
 				vunmapbuf(bp);
@@ -125,6 +120,5 @@ physio(struct cdev *dev, struct uio *uio, int ioflag)
 doerror:
 	relpbuf(bp, NULL);
 	PRELE(curproc);
-	mtx_unlock(&Giant);
 	return (error);
 }