Messages in this thread | | | From | KY Srinivasan <> | Subject | RE: [PATCH 2/2] Drivers: hv: Add Hyper-V balloon driver | Date | Wed, 10 Oct 2012 02:26:46 +0000 |
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> -----Original Message----- > From: Andrew Morton [mailto:akpm@linux-foundation.org] > Sent: Tuesday, October 09, 2012 9:15 PM > To: KY Srinivasan > Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; > devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; > andi@firstfloor.org > Subject: Re: [PATCH 2/2] Drivers: hv: Add Hyper-V balloon driver > > On Wed, 10 Oct 2012 00:09:12 +0000 KY Srinivasan <kys@microsoft.com> wrote: > > > > > + if (!pg) { > > > > + *alloc_error = true; > > > > + return i * alloc_unit; > > > > + } > > > > + > > > > + totalram_pages -= alloc_unit; > > > > > > Well, I'd consider totalram_pages to be an mm-private thing which drivers > > > shouldn't muck with. Why is this done? > > > > By modifying the totalram_pages, the information presented in /proc/meminfo > > correctly reflects what is currently assigned to the guest (MemTotal). > > eh? /proc/meminfo:MemTotal tells you the total memory in the machine. > The only thing which should change it after boot is memory hotplug. > > Modifying it in this manner puts the statistic into a state know as > "wrong". And temporarily modifying it in this fashion will cause the > tremendous amount of initialisation code which relies upon > totalram_pages for sizing to also enter the "wrong" state. > > Why on earth do balloon drivers do this? If the amount of memory which > is consumed by balloons is interesting then it should be exported via a > standalone metric, not by mucking with totalram_pages.
I see your point. I will get rid of the code that manipulates the totalram_pages.
Regards,
K. Y
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