From owner-freebsd-hackers  Sun Jul  1  2: 0:42 2001
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Date: Sun, 1 Jul 2001 04:00:34 -0500
From: Alfred Perlstein <bright@sneakerz.org>
To: "E.B. Dreger" <eddy+public+spam@noc.everquick.net>
Cc: "Michael C . Wu" <keichii@peorth.iteration.net>,
	freebsd-smp@freebsd.org, freebsd-hackers@freebsd.org
Subject: Re: Quick question: AIO / SMP / process-based threading
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References: <20010630222829.E84523@sneakerz.org> <Pine.LNX.4.20.0107010345230.29177-100000@www.everquick.net>
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* E.B. Dreger <eddy+public+spam@noc.everquick.net> [010630 22:51] wrote:
> > Date: Sat, 30 Jun 2001 22:28:29 -0500
> > From: Alfred Perlstein <bright@sneakerz.org>
> > 
> > Can you point to some specific PRs about this or crashdumps before
> > (or at least while) taking pot shots at the AIO implementation?
> 
> In the mean time, until somebody can substantiate that claim... is AIO SMP
> safe?  I see that aiocb.aio_buf is declared as "volatile", so I would
> presume so.
> 
> I just want to be sure that, if an aio call runs on one CPU, another CPU
> can access *aio_buf and be 100% certain that the data are coherent.
>
 
It should be, if you experience any problems please let us know.

> aio_buf = mmap() using MAP_HASSEMAPHORE -- good idea, bad idea, pointless?

Pointless I think.

-- 
-Alfred Perlstein [alfred@freebsd.org]
Ok, who wrote this damn function called '??'?
And why do my programs keep crashing in it?

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