Re: [PATCH]: Staging: hv: Allocate the vmbus irq dynamically

[Greg KH <gregkh@suse.de>]

On Fri, Feb 18, 2011 at 10:16:05PM +0000, KY Srinivasan wrote:
> 
> 
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@suse.de]
> > Sent: Friday, February 18, 2011 5:07 PM
> > To: KY Srinivasan
> > Cc: Greg KH; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> > virtualization@lists.osdl.org
> > Subject: Re: [PATCH]: Staging: hv: Allocate the vmbus irq dynamically
> > 
> > On Fri, Feb 18, 2011 at 10:00:04PM +0000, KY Srinivasan wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Greg KH [mailto:greg@kroah.com]
> > > > Sent: Friday, February 18, 2011 4:14 PM
> > > > To: KY Srinivasan
> > > > Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> > > > devel@linuxdriverproject.org; virtualization@lists.osdl.org
> > > > Subject: Re: [PATCH]: Staging: hv: Allocate the vmbus irq dynamically
> > > >
> > > > On Tue, Feb 15, 2011 at 11:55:35AM -0800, K. Y. Srinivasan wrote:
> > > > >
> > > > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > > > Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> > > > > Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
> > > >
> > > > You didn't run this through checkpatch.pl.
> > > >
> > > > Please do so and fix the warning it gives you.
> > > Greg, I did run the checkpatch script against this patch and the only
> > > complaint I got was with regards to the IRQF_SAMPLE_RANDOM flag that I
> > > pass. As a virtual machine, this is the only external event that the
> > > VM is going to see and so I chose to keep this flag.  Is there
> > > something that would replace this flag; looking at the Xen drivers
> > > they do pass this flag.
> > 
> > But that flag is going away, right?  And this really can't be a valid
> > source of entropy as the HV channel is pretty predictable.
> 
> Is it going away? What would replace this. Is all interrupt sources considered
> predictable?

Did you read the file that the checkpatch script told you to about this
entry?

> This is the only unpredictable thing happening in the VM and that is the reason
> I chose to keep the flag.

If you remove it, do we loose all entropy for the VM?

> > If you are only using this because Xen does/did it, that's not a valid
> > excuse :)
> Surely, you are joking.

Not at all.

> In any event I am sending you a new patch with that flag removed.

Have you tested to see if you now loose all entropy, and it causes
problems or not?

thanks,

greg k-h