From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Fri, 20 Dec 2013 16:34:01 +0000 Subject: [PATCH 2/2] arm64: dts: Reduce size of virtio block device for foundation model In-Reply-To: <20131220160522.GX31886@sirena.org.uk> References: <1387543964-15057-1-git-send-email-broonie@kernel.org> <1387543964-15057-2-git-send-email-broonie@kernel.org> <20131220142524.GB11954@localhost> <20131220160522.GX31886@sirena.org.uk> Message-ID: <20131220163401.GK25477@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Dec 20, 2013 at 04:05:22PM +0000, Mark Brown wrote: > On Fri, Dec 20, 2013 at 02:25:24PM +0000, Catalin Marinas wrote: > > On Fri, Dec 20, 2013 at 12:52:44PM +0000, Mark Brown wrote: > > > From: Mark Brown > > > > Will Deacon observed that kvmtool uses a size of 0x200 for virtio > > > block memory region and that the virtio block spec only uses 31 bytes in > > > the device specific region at 0x100 so reduce the region to a less > > > wasteful 0x200. > > > What do we waste by keeping it at 4K? That's ioremap'ed, so we use a > > full page anyway. > > This was done for consistency with the same change made in RTSM > motherboard patch so that we register the same device in the same way. > That change was at Will's request, he did point out that we might use > 16K pages in some systems IIRC but personally I'm not sure it makes a > huge difference either way - I do think we should keep all registrations > of the device consistent though to avoid user confusion about how to use > it. OK. Applied. -- Catalin