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From: el es <el.es.cr@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: Re: Stupid user with user-space questions, matrix LED driving with user space code only.
Date: Mon, 18 Feb 2013 11:55:38 +0000 (UTC)	[thread overview]
Message-ID: <loom.20130218T124824-843@post.gmane.org> (raw)
In-Reply-To: <1361163968.29540.62.camel@jonspc>

Jonathan Andrews <jon <at> jonshouse.co.uk> writes:


> 
> What about a yield alignment mechanism for user space. IE the process
> calls the kernel with a request "schedule me first after a yeild" - then
> the process at least has whatever the timer granularity is to do
> something timing critical... add a flag to ignore or defer interrupts
> and you have a semi 'hard-realtime' behaviour for user space, allowing
> user space to grab small chunks of real time. Yes a nasty looking
> facility for SMP intel servers but really useful for embedded.
> 

Seems you have some (bad?) habits from embedded programming, 
you think Linux is FreeRTOS ;)

Linux as such, as far as I read, is not a real-time OS, it will 
NOT do what you want in userspace, (maybe unless you build it with
the RT patchset?)

Better take the advice and go build a kernel driver for this display.

Or use a small microcontroller that won't have the limitations. 

> Thanks,
> Jon
> 
> 
Lukasz




      reply	other threads:[~2013-02-18 11:55 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-16 14:37 Jonathan Andrews
2013-02-17  6:22 ` anish kumar
2013-02-17 14:37   ` Jonathan Andrews
2013-02-17 15:05     ` anish kumar
2013-02-18  2:05     ` Greg KH
2013-02-18  5:06       ` Jonathan Andrews
2013-02-18 11:55         ` el es [this message]

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