Messages in this thread | | | Date | Thu, 16 Dec 2010 20:46:07 -0800 | From | Yinghai Lu <> | Subject | Re: kdump broken on 2.6.37-rc4 |
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On 12/16/2010 08:08 PM, H. Peter Anvin wrote: > On 12/16/2010 07:58 PM, 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 >> >> Thanks >> > > Hm, this seems like an epic FAIL. > > First of all, the current code still limits it to 896 MiB, so 512 MiB is > not a significant restriction.
You only have chance to get 512M under 896M but not under 512M.
> > Second, this patch only applies if "crashkernel=" is not specified, so > it doesn't even apply to your situation. current code: /* 0 means: find the address automatically */ if (crash_base <= 0) { const unsigned long long alignment = 16<<20; /* 16M */
/* * kexec want bzImage is below DEFAULT_BZIMAGE_ADDR_MAX */ crash_base = memblock_find_in_range(alignment, DEFAULT_BZIMAGE_ADDR_MAX, crash_size, alignment);
if (crash_base == MEMBLOCK_ERROR) { pr_info("crashkernel reservation failed - No suitable area found.\n"); return; } } else { unsigned long long start;
start = memblock_find_in_range(crash_base, crash_base + crash_size, crash_size, 1<<20); if (start != crash_base) { pr_info("crashkernel reservation failed - memory is in use.\n"); return; } }
first branch : will take only crash_size. second branch : will need to specify crash_base and crash_size.
> > Third, if you have to specify "crashkernel=" that means that there is > yet another problem here that should be fixed.
no, every kdump need to specify crashkernel=128M or more.
Yinghai
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