From owner-freebsd-current  Sat Feb 23 16:49: 8 2002
Delivered-To: freebsd-current@freebsd.org
Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16])
	by hub.freebsd.org (Postfix) with ESMTP
	id 58DE437B400; Sat, 23 Feb 2002 16:49:02 -0800 (PST)
Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102])
	by mailman.zeta.org.au (8.9.3/8.8.7) with ESMTP id LAA00511;
	Sun, 24 Feb 2002 11:48:55 +1100
Date: Sun, 24 Feb 2002 11:49:12 +1100 (EST)
From: Bruce Evans <bde@zeta.org.au>
X-X-Sender:  <bde@gamplex.bde.org>
To: Matthew Dillon <dillon@apollo.backplane.com>
Cc: Terry Lambert <tlambert2@mindspring.com>,
	Alfred Perlstein <alfred@FreeBSD.ORG>,
	Bosko Milekic <bmilekic@unixdaemons.com>,
	Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp>,
	<current@FreeBSD.ORG>, John Baldwin <jhb@FreeBSD.ORG>
Subject: Re: malloc_bucket() idea (was Re: How to fix malloc.)
In-Reply-To: <200202240003.g1O036164477@apollo.backplane.com>
Message-ID: <20020224111043.W30980-100000@gamplex.bde.org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-current.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-current>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-current>
X-Loop: FreeBSD.ORG

On Sat, 23 Feb 2002, Matthew Dillon wrote:

> :My version of it does less than this.  I only use it to help implement
> :spinlocks.
>
>     You put together infrastructure to deal with pending pci interrupts?
>     If so, then why not commit it (or at least commit a version #ifdef'd
>     for the i386 architecture).

It's too messy and unfinished (doesn't work right for SMP or irqs >= 16),
and dificult to untangle from my other patches.  I posted these partial
ones to attempt to inhibit() recomplication of the current critical*
functions in directions that I don't want to go :-).

> :Index: kern_switch.c
> :===================================================================
> :RCS file: /home/ncvs/src/sys/kern/kern_switch.c,v
> :retrieving revision 1.20
> :diff -u -2 -r1.20 kern_switch.c
> :--- kern_switch.c	11 Feb 2002 20:37:51 -0000	1.20
> :+++ kern_switch.c	13 Feb 2002 05:34:20 -0000
> :@@ -70,14 +70,21 @@
> : }
> :
> :-/* Critical sections that prevent preemption. */
> :+/*-
> :+ * Critical section handling.
> :+ * XXX doesn't belong here.
> :+ *
> :+ * Entering a critical section only blocks non-fast interrupts.
> :+ * critical_enter() is similar to splhigh() in a 2-level spl setup under
> :+ * old versions of FreeBSD.
> :+ *
> :+ * Exiting from all critical sections unblocks non-fast interrupts and runs
> :+ * the handlers of any that were blocked.  critical_exit() is similar to
> :+ * spl(old_level) in a 2-level spl setup under old versions of FreeBSD.
> :+ */
> : void
> : critical_enter(void)
> : {
> :-	struct thread *td;
> :
> :-	td = curthread;
> :-	if (td->td_critnest == 0)
> :-		td->td_savecrit = cpu_critical_enter();
> :-	td->td_critnest++;
> :+	curthread->td_critnest++;
> : }
> :
> :@@ -85,12 +92,7 @@
> : critical_exit(void)
> : {
> :-	struct thread *td;
> :
> :-	td = curthread;
> :-	if (td->td_critnest == 1) {
> :-		td->td_critnest = 0;
> :-		cpu_critical_exit(td->td_savecrit);
> :-	} else
> :-		td->td_critnest--;
> :+	if (--curthread->td_critnest == 0 && (ipending | spending) != 0)
> :+		unpend();
> : }

ipending here works much as in RELENG_4.  It is ORed into by sched_ithd()
if curthread->td_critnest != 0.  Nothing special is needed for pci
(the ICU masks pending interrupts).

Bruce


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message