On 2016/04/05 at 17:13, Michael Holzheu wrote: > Hello Xunlei, > > On Tue, 5 Apr 2016 15:09:59 +0800 > Xunlei Pang <xlpang at redhat.com> wrote: >> Commit 3f625002581b ("kexec: introduce a protection mechanism >> for the crashkernel reserved memory") is a similar mechanism >> for protecting the crash kernel reserved memory to previous >> crash_map/unmap_reserved_pages() implementation, the new one >> is more generic in name and cleaner in code (besides, some >> arch may not be allowed to unmap the pgtable). >> >> Therefore, this patch consolidates them, and uses the new >> arch_kexec_protect(unprotect)_crashkres() to replace former >> crash_map/unmap_reserved_pages() which by now has been only >> used by S390. >> >> The consolidation work needs the crash memory to be mapped >> initially, so get rid of S390 crash kernel memblock removal >> in reserve_crashkernel(). Oops, the final paragraph of the changelog should be changed to: The consolidation work needs the crash memory to be mapped initially, this is done in machine_kdump_pm_init() which is run after reserve_crashkernel(). Once kdump kernel is loaded, the new arch_kexec_protect_crashkres() implemented for S390 will actually unmap the pgtable like before. > If you fix this comment, I am fine with your patch. > > Acked-by: Michael Holzheu <holzheu at linux.vnet.ibm.com> > Thanks, Xunlei