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From: Ronald G Minnich <rminnich@lanl.gov>
To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Subject: Re: [9fans] const
Date: Fri,  9 Dec 2005 10:01:18 -0700	[thread overview]
Message-ID: <4399B85E.1050706@lanl.gov> (raw)
In-Reply-To: <3e1162e60512090825n4d944cc8yb2f668e3deb64dec@mail.gmail.com>

David Leimbach wrote:

> Volatile is useful for telling compilers not to stick  data in 
> registers, which is helpful for multi-threaded situations with shared 
> memory ... sometimes :)

and, stuff that tickles hardware. Refer to the old crazy stuff bsd did 
in the early 80s to get around those issues and still optimize drivers. 
Now, wonder if that script could even be found at this point.

I think I missed the part of the discussion that explains how to do 
mmap'ed I/O without volatile, and a good idea of how to tweak the 
compiler, such that:

while (x->statux & BUSY)
	;

works. If the answer is "don't optimize that functions, you idiot!" I'm 
actually ok with that.

ron


  parent reply	other threads:[~2005-12-09 17:01 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-12-07 10:34 Steve Simon
2005-12-07 12:17 ` Russ Cox
2005-12-07 13:01   ` erik quanstrom
     [not found]   ` <000401c5fb32$64502e00$14aaa8c0@utelsystems.local>
2005-12-07 14:10     ` "Nils O. Selåsdal"
2005-12-07 15:05       ` Steve Simon
2005-12-07 15:30         ` Lucio De Re
2005-12-07 15:53           ` C H Forsyth
     [not found]         ` <1E68F99F-78D7-4321-BE56-7D0319212596@telus.net>
2005-12-07 16:11           ` "Nils O. Selåsdal"
2005-12-07 17:27             ` Paul Lalonde
2005-12-07 16:23 ` jmk
2005-12-07 17:28   ` Skip Tavakkolian
2005-12-07 18:51   ` Joel Salomon
2005-12-07 18:58     ` Charles Forsyth
2005-12-07 19:30       ` Joel Salomon
2005-12-07 19:36         ` Brantley Coile
2005-12-07 19:51         ` rog
2005-12-07 21:07         ` Charles Forsyth
2005-12-07 21:18           ` Bruce Ellis
2005-12-07 21:22           ` Paul Lalonde
2005-12-07 22:04             ` Rob Pike
2005-12-07 22:44           ` Micah Stetson
2005-12-07 22:44             ` Micah Stetson
2005-12-07 22:46               ` Brantley Coile
2005-12-07 20:33     ` Skip Tavakkolian
2005-12-08  7:39 ` geoff
2005-12-08  7:53   ` Lucio De Re
2005-12-08  7:54     ` geoff
2005-12-08 10:23       ` Bruce Ellis
2005-12-08 15:58   ` Brantley Coile
2005-12-09  1:44     ` geoff
2005-12-09  2:04       ` Russ Cox
2005-12-09  2:19         ` geoff
2005-12-09  9:54         ` Charles Forsyth
2005-12-09 16:25   ` David Leimbach
2005-12-09 16:59     ` Richard Bilson
2005-12-09 17:42       ` David Leimbach
2005-12-09 19:17         ` Richard Bilson
2005-12-09 17:01     ` Ronald G Minnich [this message]
2005-12-09 17:39       ` Russ Cox
2005-12-09 17:40       ` [9fans] PCICIA Modem TamTam
2005-12-09 18:59         ` Sascha Retzki
2005-12-12 15:07         ` Paweł Lasek
2005-12-26  9:00           ` Martin C. Atkins
2005-12-26 14:19             ` Paweł Lasek
2005-12-09 19:37       ` [9fans] Re: const Nikita Danilov
2005-12-09 20:30         ` Russ Cox
2005-12-09 20:37         ` Ronald G Minnich

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