From owner-freebsd-questions Wed Jul 1 00:03:21 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA07250 for freebsd-questions-outgoing; Wed, 1 Jul 1998 00:03:21 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from implode.root.com (implode.root.com [198.145.90.17]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id AAA07245 for ; Wed, 1 Jul 1998 00:03:19 -0700 (PDT) (envelope-from root@implode.root.com) Received: from implode.root.com (localhost [127.0.0.1]) by implode.root.com (8.8.5/8.8.5) with ESMTP id AAA01024; Wed, 1 Jul 1998 00:02:50 -0700 (PDT) Message-Id: <199807010702.AAA01024@implode.root.com> To: sja@world.std.com (Stuart J Adams) cc: freebsd-questions@FreeBSD.ORG Subject: Re: splnet, splx and tsleep In-reply-to: Your message of "Tue, 30 Jun 1998 15:00:56 EDT." <199806301900.AA29089@world.std.com> From: David Greenman Reply-To: dg@root.com Date: Wed, 01 Jul 1998 00:02:49 -0700 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >I am trying to understand the exact effects >of splnet and splimp in the kernel. > >When running at splnet/splimp a process >cannot be preempted out due to time slicing >right ??? A process can't be preempted due to scheduling when running anywhere in the kernel. >what happens when tsleep is called while >at splnet ??? This happens in the accept >system call, the system can't be left at >the splnet priority level until a connection >is made. How does tsleep effect the current >spl ??? The spl prior to the sleep is saved, spl0 (splnone) is set, and another process is scheduled. The spl will be restored later when the wakeup occurs. >Is there a good explanation on the net or in >book about these kernel architectural issues ??? Kirk's book is usually a good reference. -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message