On 08/26/2014 06:20, Ralf Baechle wrote: > On Tue, Aug 26, 2014 at 05:27:28AM -0400, Joshua Kinard wrote: > >> Okay, so from the "make kmap cache coloring aware" thread, I've been playing >> with larger PAGE_SIZE values on the Octane and O2 for the last few hours. >> 16k and 64k used to, in the past, never get far after init (usually died >> *at* init) That appears to have changed now. Most programs seem to >> JustWork(), but very randomly, I am getting a signal -4, illegal instruction >> (SIGILL) on the Octane. Both systems are running kernels w/ 64k PAGE_SIZE >> at the moment. >> >> I cannot reproduce it on demand, so I'm not really sure what the cause could >> be. PAGE_SIZE should be largely transparent to userland these days, so I am >> wondering if this might be more oddities w/ an R14000 CPU. > > This sound very unlikely as the CPU was primarily designed to run IRIX and > SGI's systems were using 16k or even 64k page size. > > What userland are you running and how old is it? Are you seeing different > results for 16k and 64k? o32 userland is the primary on both systems. However, the last SIGILL was under the 64k PAGE_SIZE kernel inside of an n32 chroot compiling the 'boost' package on the Octane, which I restarted that and it's not complained since. Also got SIGILL on the 16k PAGE_SIZE kernel when I booted 16k PAGE_SIZE the first time and ran 'ps'. Subsequent runs of 'ps' didn't reproduce the error. Also saw SIGILLs in the bootlog of the 16k PAGE_SIZE kernel when "rm" was ran once (couldn't reproduce) and when mdadm tried to put one of the arrays back together. Subsequent runs using similar argument lines don't reproduce once I got to a root shell. Being it's a Gentoo install...the o32 userland is pretty fresh. Especially on the Octane, where I literally rebuilt the old userland over 2-3 times just to make sure all the old 5-year cruft was gone. The n32 userland chroot is brand-spanking new. gcc-4.7.x only for now on both, because of PR61538 in gcc. Latest binutils. The O2 is chugging away happily so far in updating a bunch of packages. So I am leaning towards this being another quirk I have to hunt down in the Octane's code again. There isn't much in the Octane-specific code that deals with memory, though -- it seems the higher-level MIPS memory code handles most things just fine. -- Joshua Kinard Gentoo/MIPS kumba@xxxxxxxxxx 4096R/D25D95E3 2011-03-28 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic
