Messages in this thread | | | From | David Hildenbrand <> | Subject | Re: [RFC/RFT PATCH 1/5] s390: make crashk_res resource a child of "System RAM" | Date | Tue, 1 Jun 2021 11:02:17 +0200 |
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On 01.06.21 10:45, David Hildenbrand wrote: > On 31.05.21 14:29, Mike Rapoport wrote: >> From: Mike Rapoport <rppt@linux.ibm.com> >> >> Commit 4e042af463f8 ("s390/kexec: fix crash on resize of reserved memory") >> added a comment that says "crash kernel resource should not be part of the >> System RAM resource" but never explained why. As it looks from the code in >> the kernel and in kexec there is no actual reason for that. > > Are you sure? > > Looking at kexec-tools: kexec/arch/s390/kexec-s390.c > > get_memory_ranges_s390() wants "System RAM" and Crash kernel only with > "with_crashk=1". Your patch would change that. "Crash kernel" would > always be included if you make it a child of "System RAM". > > Further, get_memory_ranges() and is_crashkernel_mem_reserved() look out > for "Crash kernel\n" via parse_iomem_single(). > > However, parse_iomem_single() does not care about ranges that start with > spaces IIRC via > sscanf(line, "%llx-%llx : %n" ...
I think I'm wrong about that one because I read
"Input white-space characters (as specified by the isspace function) are skipped, unless the specification includes a [ , c , or n specifier"
So having it as a child won't affect parse_iomem_single().
-- Thanks,
David / dhildenb
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