Messages in this thread | | | Date | Thu, 03 Feb 2011 12:37:40 -0800 | From | Yinghai Lu <> | Subject | Re: [PATCH - resend] memblock: Don't adjust size in memblock_find_base() |
| |
On 02/03/2011 12:25 PM, Andrew Morton wrote: > On Fri, 28 Jan 2011 16:37:47 -0800 > Yinghai Lu <yinghai@kernel.org> wrote: > >> >> While applying patch to use memblock to find aperture for 64bit x86. >> Ingo found system with 1g + force_iommu >> >>> No AGP bridge found >>> Node 0: aperture @ 38000000 size 32 MB >>> Aperture pointing to e820 RAM. Ignoring. >>> Your BIOS doesn't leave a aperture memory hole >>> Please enable the IOMMU option in the BIOS setup >>> This costs you 64 MB of RAM >>> Cannot allocate aperture memory hole (0,65536K) > > I'm trying to work out if we should backport this fix into earlier > kernels and as is often the case, I wasn't given enough information. > > What are the end-user visible effects of this? The kernel cannot use > the AGP bridge? 64MB of RAM wasted? Something else?
that is needed for further cleanup memblock with x86.
http://git.kernel.org/?p=linux/kernel/git/tip/linux-2.6-tip.git;a=shortlog;h=refs/heads/x86/bootmem
but it triggers another old bug in core memblock on one Ingo test machine. (with 1g ram but have iommu forced set for debug) end-user is not supposed to have this conf.
Thanks
Yinghai
| |