On Mon, May 23, 2016 at 09:21:22AM -0700, David Daney wrote: > On 05/23/2016 08:20 AM, Ralf Baechle wrote: > >On Mon, May 23, 2016 at 06:13:46PM +0300, Aaro Koskinen wrote: > >>I'm getting kernel crashes (see below) reliably when building Perl in > >>parallel (make -j16) on OCTEON EBH5600 board (8 cores, 4 GB RAM) with > >>Linux 4.6. > >> > >>It seems that CONFIG_TRANSPARENT_HUGEPAGE has something to do with the > >>issue - disabling it makes build go through fine. > >> > >>Any ideas? > > > >I thought it was working except on SGI Origin 200/2000 aka IP27 where > >Joshua Kinard (added to cc) was hitting issues as well. > > > >Joshua, does that similar to the issues you were hitting? > > There is nothing OCTEON specific in the THP code, or huge pages in general. > > That said, we have seen other THP related failures, and have never been able > to find the cause. > > If someone can come up with a reproducible test case that triggers quickly, > we can run it in our simulator and easily find the problem. Trying to build Perl is a reliable reproducer. Is that too heavyweight for your simulator? I was able to reproduce this also on EdgeRouter Pro, but there the kernel does not fail, only compiler dies with SIGBUS: [ 315.095264] Data bus error, epc == 0000000000a801c4, ra == 0000000000a80624 And without THP the build is fine. I also tried CN68XX board with 16 GB RAM and also there I get SIGBUS failure instead of Machine Check. A.
