Messages in this thread | | | From | (Eric W. Biederman) | Date | Thu, 21 Mar 2013 00:22:59 -0700 | Subject | Re: [PATCH v3 18/21] vmcore: check if vmcore objects satify mmap()'s page-size boundary requirement |
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HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> writes:
> OK, rigorously, suceess or faliure of the requested free pages > allocation depends on actual memory layout at the 2nd kernel boot. To > increase the possibility of allocating memory, we have no method but > reserve more memory for the 2nd kernel now.
Good enough. If there are fragmentation issues that cause allocation problems on larger boxes we can use vmalloc and remap_vmalloc_range, but we certainly don't need to start there.
Especialy as for most 8 or 16 core boxes we are talking about a 4KiB or an 8KiBP allocation. Aka order 0 or order 1.
Adding more memory is also useful. It is important in general to keep the amount of memory needed for the kdump kernel low.
Eric
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