Messages in this thread | | | Date | Fri, 17 Dec 2010 13:02:42 -0500 | From | Vivek Goyal <> | Subject | Re: kdump broken on 2.6.37-rc4 |
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On Fri, Dec 17, 2010 at 09:56:42AM -0800, H. Peter Anvin wrote: > On 12/17/2010 09:01 AM, Vivek Goyal wrote: > > On Thu, Dec 16, 2010 at 07:58:48PM -0800, Yinghai wrote: > >> Please don't do that to 64 bit > >> > >> My big system with 1024g memory and a lot of cards with rhel 6 to make kdump work must have crashkernel=512m and second kernel need to take pci=nomsi > >> > > > > I agree here that we should not do it for 64 bit. > > > > - Just because we need it for 32 bit does not mean we should limit it for > > 64bit. And we do want to have the capability to boot the kernel from as > > high memory as possible so creating another aritificial limit is counter > > to that. > > > > - I would not worry too much about backward compatibility and allow > > booting 32bit kernel till 768MB. The reason being that most of the > > distros use same kernel for crash dumping as regular kernel. Maintainig > > two separate kernels is big hassle. > > > > So a small set of people who run into issue, would need to change kernel > > command line "crashkernel=128M@64M" or something similar. > > > > Do we have actual testing for how high the 64-bit kernel will load?
I will do some experiments on my box today and let you know.
>I'm assuming that the usage of a 32-bit kdump kernel for a 64-bit main > kernel is nonexistent.
In the past I have run into 1-2 folks who were using 32bit kdump kernel on 64bit main. But again for those, the workaround is to specify the different crashkernel= syntax and explicityly specify where to reserve memory.
Thanks Vivek
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