> -----Original Message----- > From: Greg KH [mailto:gregkh@xxxxxxx] > Sent: Friday, February 18, 2011 5:29 PM > To: KY Srinivasan > Cc: Greg KH; linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > virtualization@xxxxxxxxxxxxxx > Subject: Re: [PATCH]: Staging: hv: Allocate the vmbus irq dynamically > > On Fri, Feb 18, 2011 at 10:16:05PM +0000, KY Srinivasan wrote: > > > > > > > -----Original Message----- > > > From: Greg KH [mailto:gregkh@xxxxxxx] > > > Sent: Friday, February 18, 2011 5:07 PM > > > To: KY Srinivasan > > > Cc: Greg KH; linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > > > virtualization@xxxxxxxxxxxxxx > > > 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@xxxxxxxxx] > > > > > Sent: Friday, February 18, 2011 4:14 PM > > > > > To: KY Srinivasan > > > > > Cc: gregkh@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > > > > devel@xxxxxxxxxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxx > > > > > 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@xxxxxxxxxxxxx> > > > > > > Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> > > > > > > Signed-off-by: Hank Janssen <hjanssen@xxxxxxxxxxxxx> > > > > > > > > > > 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? It is only after reading the document, I decided to keep that flag. Please note this is not a question of some interrupt sources not being a good source of entropy; for this VM this is the only source of interrupts. The document on this flag talked about how people were incorrectly marking their interrupt as an entropy source; in this case there is not much of a choice. > > > 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. To set the record straight here, this flag is in the existing code. After I ran checkpatch, I toyed with the idea of getting rid of this. Then I decided to keep it for all the reasons I mentioned earlier. > > > 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? I am glad you asked me to test it. When I remove this flag, the entropy goes down significantly and this is not surprising. Looking at /proc/sys/kernel/entropy/entropy_avail, with the original patch after a couple of compiles the number would be in thousands. With that flag removed, I have the VM up for about an hour, even after a couple of compiles, the entropy number is yet to crack 200. Let me know how you want to proceed here. Regards, K. Y _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
