Messages in this thread | | | Date | Sat, 10 Mar 2012 16:38:29 +0800 | From | Cong Wang <> | Subject | Re: [PATCH v2] kdump x86: fix total mem size calculation for reservation |
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On 03/10/2012 12:56 PM, Dave Young wrote: > crashkernel reservation need know the total memory size. Current get_total_mem > simply use max_pfn - min_low_pfn. It is wrong because it will including > memory holes in the middle. > > Especially for kvm guest with memory> 0xe0000000, there's below in qemu code: > qemu split memory as below: > if (ram_size>= 0xe0000000 ) { > above_4g_mem_size = ram_size - 0xe0000000; > below_4g_mem_size = 0xe0000000; > } else { > below_4g_mem_size = ram_size; > } > So for 4G mem guest, seabios will insert a 512M usable region beyond of 4G. > Thus in above case max_pfn - min_low_pfn will be more than original memsize. > > Fixing this issue by using memblock_phys_mem_size() to get the total memsize. > > [v1 -> v2]: refresh the patch based on latest linus tree >
Looks good to my eyes,
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Can you post the result of crashkernel after this patch to convince people?
Thanks.
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