ts-7000
[Top] [All Lists]

[ts-7000] Re: Inconsistent usleep and ITIMER_REAL

To:
Subject: [ts-7000] Re: Inconsistent usleep and ITIMER_REAL
From: "MrRealityCheck" <>
Date: Tue, 27 Nov 2012 02:01:56 -0000
I thought about that but that it seems like I'd not really be solving the 
problem.  I suppose I have nothing to lose but a lot of time.

FYI, the wiki is here:

https://rt.wiki.kernel.org/index.php/Main_Page

I just find it worrisome that core timing functions are suddenly that 
unpredictable.  If I knew how these functions tied into the hardware, I might 
be able to determine if I've screwed something up which is entirely possible 
given that I've been taking the ynezz/mcrapet code and adding 7350-specific 
addresses/features.  I'm tempted to go brute force and try one version after 
another until it breaks.


--- In  harry olar <> wrote:
>
> You could try the rt patch
> http://www.kernel.org/pub/linux/kernel/projects/rt/
>
>
>
>
> ________________________________
>  From: MrRealityCheck <>
> To: 
> Sent: Saturday, November 24, 2012 9:00 PM
> Subject: [ts-7000] Inconsistent usleep and ITIMER_REAL
> 
>
>  
> So, I've been using a 3.0.4 kernel from ynezz/mcrapet tweaked for a 7350 for 
> a while now.  I also set the kernel HZ to 1000 so I could get close to 
> millisecond timing.  That's been working fine.  usleep is pretty consistent.  
> Also, ITIMER_REAL has been pretty consistent.  I've used this to check the 
> kernel frequency with some code I found via google.  The Hz value hovers 
> around 980 Hz.  Plus or minus less than 5%.
>
> Now, I wanted to upgrade the kernel.  I started with stock 3.5.7 and 
> attempted to apply the 7350 specific and TS board specific stuff e.g. the SD 
> card drivers.  When I build the kernel however, my kernel frequency becomes 
> really unpredictable varying from as little as 450 Hz to as much as 950 Hz.  
> Both usleep and ITIMER_REAL are affected.  I can't figure out what I'm doing 
> wrong or if the kernel code itself is to blame.  I've tried a 3.6.6 kernel 
> and I've tried ynezz's 3.3.8 kernel as well.  It's possible I missed 
> something because the ynezz code doesn't have 7350-specific stuff.
>
> Any ideas?  I've posted something about this to Linuxquestions but have yet 
> to get a response.
>




------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ts-7000/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/ts-7000/join
    (Yahoo! ID required)

<*> To change settings via email:
    
    

<*> To unsubscribe from this group, send an email to:
    

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/

<Prev in Thread] Current Thread [Next in Thread>
Admin

Disclaimer: Neither Andrew Taylor nor the University of NSW School of Computer and Engineering take any responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU