From owner-freebsd-hackers Wed Apr 3 08:44:05 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id IAA06813 for hackers-outgoing; Wed, 3 Apr 1996 08:44:05 -0800 (PST) Received: from austin.polstra.com (austin.polstra.com [206.213.73.10]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id IAA06758 for ; Wed, 3 Apr 1996 08:43:57 -0800 (PST) Received: from austin.polstra.com (jdp@localhost) by austin.polstra.com (8.7.5/8.6.12) with ESMTP id IAA04634; Wed, 3 Apr 1996 08:43:14 -0800 (PST) Message-Id: <199604031643.IAA04634@austin.polstra.com> To: msmith@atrad.adelaide.edu.au Cc: freebsd-hackers@freebsd.org Subject: Re: i386 rep (blah) and interrupts... In-reply-to: <199604030828.RAA19778@genesis.atrad.adelaide.edu.au> Date: Wed, 03 Apr 1996 08:43:13 -0800 From: John Polstra Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Michael Smith asks: > In the read function, one of the input methods I'm contemplating basically > involves > > insw(sc->sc_port,sc->sc_buf,sc->sc_pending); > > ... which basically translates to the i386 'rep insw' construct. > > It's not inconcievable that sc->sc_pending could run to several tens of K, > and what I don't know is whether this construct is interruptible or not. Yes, the "rep" constructs are interruptible. They service pending interrupts at the beginning of each iteration, according the the 80386 programmer's reference manual. -- John Polstra jdp@polstra.com John D. Polstra & Co., Inc. Seattle, Washington USA "Self-knowledge is always bad news." -- John Barth