From owner-freebsd-questions Tue Mar 16 12:18:41 1999 Delivered-To: freebsd-questions@freebsd.org Received: from tornado.cisco.com (tornado.cisco.com [171.69.104.22]) by hub.freebsd.org (Postfix) with ESMTP id 506C814CD2 for ; Tue, 16 Mar 1999 12:18:25 -0800 (PST) (envelope-from bmcgover@bmcgover-pc.cisco.com) Received: from bmcgover-pc.cisco.com (bmcgover-pc.cisco.com [171.69.104.147]) by tornado.cisco.com (8.8.5-Cisco.1/8.6.5) with ESMTP id PAA08059 for ; Tue, 16 Mar 1999 15:18:06 -0500 (EST) Received: from bmcgover-pc.cisco.com (localhost.pa.dtd.cisco.com [127.0.0.1]) by bmcgover-pc.cisco.com (8.9.2/8.9.2) with ESMTP id PAA00661 for ; Tue, 16 Mar 1999 15:18:05 -0500 (EST) (envelope-from bmcgover@bmcgover-pc.cisco.com) Message-Id: <199903162018.PAA00661@bmcgover-pc.cisco.com> To: questions@freebsd.org Reply-To: bmcgover@cisco.com Subject: timeout() as pseudo-interrupts Date: Tue, 16 Mar 1999 15:18:05 -0500 From: Brian McGovern Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG We've had an all day discussion here as to whether this is a problem or not... Hopefully someone can shed some light... We're having problems with a terminal driver that uses timeout() to effectively "poll" the hardware. Based on some stack traces we're seeing, it appears that the code called by the back end of timeout is stomping on other tty-level code. Timeout() claims to run the code at spl level 0. However, it _seems_ to be called by hardclock(), which runs at splhigh(). The question is whether this is a good method for simulating poll cycles for TTY-type devices, or whether this will cause problems? -Brian To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message