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From: Marcel Siegert <mws@linuxtv.org>
To: Trent Piepho <xyzzy@speakeasy.org>
Subject: Re: [v4l-dvb-maintainer] Re: dvb shared datastructure bug?
Date: Tue, 13 Feb 2007 14:21:05 +0100
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Cc: Jakub Jelinek <jakub@redhat.com>, Manu Abraham <abraham.manu@gmail.com>,
       v4l-dvb-maintainer@linuxtv.org, mchehab@infradead.org,
       linux-kernel@vger.kernel.org, Arjan van de Ven <arjan@infradead.org>
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On Tuesday 13 February 2007, Trent Piepho wrote:
> On Tue, 13 Feb 2007, Jakub Jelinek wrote:
> > Wouldn't it be better to kmalloc both struct dvb_device and
> > struct file_operations together instead of doing 2 separate allocations?
> > struct dvd_device_plus_fops
> > {
> >   struct dvb_device dev;
> >   struct file_operations fops;
> > } *dev_fops = kmalloc (sizeof (struct dvd_device_plus_fops), GFP_KERNEL);
> > *pdvbdev = dvbdev = (struct dvb_device *)dev_fops;
> > if (dev_fops == NULL)
> >   error handling;
> > memset (&dev_fops->fops, 0, sizeof (dev_fops->fops));
> > ...
> > dvbdev->fops = &dev_fops->fops;
> 
> Maybe change struct dvb_device:
> 
>  struct dvb_device {
>          struct list_head list_head;
> -        struct file_operations *fops;
> +        struct file_operations fops;
>          struct dvb_adapter *adapter;
> 
> 
hi trent, 

your suggestion is correct and useful, 
but this would mean a lot of more work to do, 
and maybe creates new issues.

we should get a working - non issued - v4l-dvb tree and
afterwards start to review, optimize things.

can we put that on wait for the future?

regards 
marcel