From: Bill Huey (hui) <billh@gnuppy.monkey.org>
To: Esben Nielsen <simlo@phys.au.dk>
Cc: Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
david singleton <dsingleton@mvista.com>,
linux-kernel@vger.kernel.org
Subject: Re: RT Mutex patch and tester [PREEMPT_RT]
Date: Fri, 13 Jan 2006 00:07:34 -0800 [thread overview]
Message-ID: <20060113080734.GA22091@gnuppy.monkey.org> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0601121337480.30644-100000@lifa03.phys.au.dk>
On Thu, Jan 12, 2006 at 01:54:23PM +0100, Esben Nielsen wrote:
> turnstiles? What is that?
http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/kern/subr_turnstile.c
Please, read. Now tell me or not if that looks familiar ? :)
Moving closer an implementation is arguable, but it is something that
should be considered somewhat since folks in both the Solaris (and
FreeBSD) communities have given a lot more consideration to these issues.
The stack allocated objects are fine for now. Priority inheritance
chains should never get long with a fine grained kernel, so the use
of a stack allocated object and migrating pi-ed waiters should not
be a major real world issue in Linux yet.
Folks should also consider using an adaptive spin in the __grab_lock() (sp?)
related loops as a possible way of optimizing away the immediate blocks.
FreeBSD actually checks the owner of a lock aacross another processor
to see if it's actively running, "current", and will block or wait if
it's running or not respectively. It's pretty trivial code, so it's
not a big issue to implement. This is ignoring the CPU local storage
issues.
bill
next prev parent reply other threads:[~2006-01-13 8:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-11 17:25 RT Mutex patch and tester [PREEMPT_RT] Esben Nielsen
2006-01-11 17:51 ` Steven Rostedt
2006-01-11 21:45 ` Esben Nielsen
2006-01-12 11:33 ` Bill Huey
2006-01-12 12:54 ` Esben Nielsen
2006-01-13 8:07 ` Bill Huey [this message]
2006-01-13 8:47 ` Esben Nielsen
2006-01-13 10:19 ` Bill Huey
2006-01-15 4:24 ` Bill Huey
2006-01-16 8:35 ` Esben Nielsen
2006-01-16 10:22 ` Bill Huey
2006-01-16 10:53 ` Bill Huey
2006-01-16 11:30 ` Esben Nielsen
[not found] ` <Pine.LNX.4.44L0.0601181120100.1993-201000@lifa02.phys.au.dk>
2006-01-18 10:38 ` Ingo Molnar
2006-01-18 12:49 ` Steven Rostedt
2006-01-18 14:18 ` Esben Nielsen
[not found] ` <Pine.LNX.4.44L0.0601230047290.31387-201000@lifa01.phys.au.dk>
2006-01-23 0:38 ` david singleton
2006-01-23 2:04 ` Bill Huey
2006-01-23 9:33 ` Esben Nielsen
2006-01-23 14:23 ` Steven Rostedt
2006-01-23 15:14 ` Esben Nielsen
2006-01-27 15:18 ` Esben Nielsen
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