From owner-freebsd-bugs@FreeBSD.ORG  Thu May  8 17:10:07 2003
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@hub.freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id F139737B401
	for <freebsd-bugs@hub.freebsd.org>;
	Thu,  8 May 2003 17:10:06 -0700 (PDT)
Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 9BFBD43F3F
	for <freebsd-bugs@hub.freebsd.org>;
	Thu,  8 May 2003 17:10:06 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1])
	by freefall.freebsd.org (8.12.9/8.12.9) with ESMTP id h490A6Up066731
	for <freebsd-bugs@freefall.freebsd.org>;
	Thu, 8 May 2003 17:10:06 -0700 (PDT)
	(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.12.9/8.12.9/Submit) id h490A6Pl066730;
	Thu, 8 May 2003 17:10:06 -0700 (PDT)
Date: Thu, 8 May 2003 17:10:06 -0700 (PDT)
Message-Id: <200305090010.h490A6Pl066730@freefall.freebsd.org>
To: freebsd-bugs@FreeBSD.org
From: Bruce Evans <bde@zeta.org.au>
Subject: Re: kern/51982: sio1: interrupt-level buffer overflows
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
Reply-To: Bruce Evans <bde@zeta.org.au>
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 09 May 2003 00:10:07 -0000

The following reply was made to PR kern/51982; it has been noted by GNATS.

From: Bruce Evans <bde@zeta.org.au>
To: Ian Freislich <ianf@za.uu.net>
Cc: FreeBSD-gnats-submit@freebsd.org, freebsd-bugs@freebsd.org
Subject: Re: kern/51982: sio1: interrupt-level buffer overflows
Date: Fri, 9 May 2003 10:04:41 +1000 (EST)

 On Fri, 9 May 2003, Bruce Evans wrote:
 
 > ...
 > The original version provides enough buffering for about 4 hardclock
 > ticks (default 40 msec on i386's; much smaller on some other arches)
 > of input at full speed.  The third version provides 400 msec of
 > buffering.
 
 PS: you should also try to find what is holding Giant for more than 40
 msec.  Most syscalls hold it from near their start to near their
 completion, but most syscalls don't take nearly that long.  It is
 easy to write broken ones that do - just spin for a long time, or
 return a huge amount of data via sysctl.
 
 Bruce