Messages in this thread | | | Date | Tue, 25 Aug 2009 15:54:22 +0530 | From | "M. Mohan Kumar" <> | Subject | Re: [Patch 6/8] powerpc: add CONFIG_KEXEC_AUTO_RESERVE |
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On Tue, Aug 25, 2009 at 02:37:12PM +0800, Amerigo Wang wrote: > M. Mohan Kumar wrote: >> On Mon, Aug 24, 2009 at 11:44:03PM +1000, Michael Ellerman wrote: >> >>> On Fri, 2009-08-21 at 02:55 -0400, Amerigo Wang wrote: >>>
>>> That aside, I don't see how this will be useful in practice, if it only >>> works for memory sizes over 4G? Or are we saying that people with less >>> than 4G don't need crash kernels? If we're not saying that, those users, >>> or those users' distros, still need to do some logic to work out if they >>> have < 4GB of memory and if so pick a crash kernel size. So why can't >>> they pick the size in the > 4GB case also? >>> >> >> True, I wanted to test the patch and when tested on a ppc64 machine which >> has RAM less than 4GB, I have to modify arch_default_crash_size routine to >> return 256MB (I didn't have a PPC64 machine with more than 4GB RAM handy). >> So its better to consider machines with less than 4GB RAM also. >> > > OK, how about 2G on ppc? Is it safe to reserve 256M when I have 2G?
I would prefer 2G-4G 128MB.
> >> PPC64 crashkernel base is always 32MB. So at least ppc64 code should have >> its own arch_default_crash_base to return 32MB to avoid the kernel warning >> message "Crash kernel location must be 0x2000000" >> > Hmm, good point, how about KDUMP_KERNELBASE? It looks fine for both ppc > and ppc64.
Yes, you can use KDUMP_KERNELBASE for arch_default_crash_base
Regards, M. Mohan Kumar
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