> Subject: Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for > fast (de)inflating & fast live migration > > On 12/14/2016 12:59 AM, Li, Liang Z wrote: > >> Subject: Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon > >> for fast (de)inflating & fast live migration > >> > >> On 12/08/2016 08:45 PM, Li, Liang Z wrote: > >>> What's the conclusion of your discussion? It seems you want some > >>> statistic before deciding whether to ripping the bitmap from the > >>> ABI, am I right? > >> > >> I think Andrea and David feel pretty strongly that we should remove > >> the bitmap, unless we have some data to support keeping it. I don't > >> feel as strongly about it, but I think their critique of it is pretty > >> valid. I think the consensus is that the bitmap needs to go. > >> > >> The only real question IMNHO is whether we should do a power-of-2 or > >> a length. But, if we have 12 bits, then the argument for doing > >> length is pretty strong. We don't need anywhere near 12 bits if doing > power-of-2. > > > > Just found the MAX_ORDER should be limited to 12 if use length instead > > of order, If the MAX_ORDER is configured to a value bigger than 12, it > > will make things more complex to handle this case. > > > > If use order, we need to break a large memory range whose length is > > not the power of 2 into several small ranges, it also make the code complex. > > I can't imagine it makes the code that much more complex. It adds a for loop. > Right? > Yes, just a little. :) > > It seems we leave too many bit for the pfn, and the bits leave for > > length is not enough, How about keep 45 bits for the pfn and 19 bits > > for length, 45 bits for pfn can cover 57 bits physical address, that should be > enough in the near feature. > > > > What's your opinion? > > I still think 'order' makes a lot of sense. But, as you say, 57 bits is enough for > x86 for a while. Other architectures.... who knows? Yes. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href