On Mon, Mar 20, 2017 at 02:11:31PM +0800, Xunlei Pang wrote: > I found that the kdump is broken on linux-4.11.0-rc2+ That's actually tip tree or linux-next. The problematic change is not in Linus' tree. > , probably > due to the 5level-paging feature that "#define p4d_present(p4d) 1", > as a result in ident_p4d_init(), it will go into ident_pud_init() > directly without allocating the new pud. > > Looks like this patch can make it work again. Okay, that's bisectability issue. Uncovered by splitting my patchset into parts. Could you check if applying "Part 2" of 5-level paging changes[1] would help you? Making the code work with both <asm-generic/5level-fixup.h> and <asm-generic/pgtable-nop4d.h> would make it even uglier. Not sure if it makes sense to address it on its own if second part fixes the situation. [1] http://lkml.kernel.org/r/20170317185515.8636-1-kirill.shutemov at linux.intel.com -- Kirill A. Shutemov
