On Wed, 2013-10-09 at 19:18 +0200, Ingo Molnar wrote: > * Ingo Molnar <mi...@kernel.org> wrote: > > > > > * Peter Zijlstra <pet...@infradead.org> wrote: > > > > > On Wed, Oct 09, 2013 at 08:19:11PM +0800, Fengguang Wu wrote: > > > > > > Fengguang, I do not think this will help, but just in case. Could > > > > > > you > > > > > > show the result of > > > > > > > > > > > > $ kernel/task_work.s > > > > > > > > Update: I recompiled the kernel with gcc 4.4.7 and find it booting fine! > > > > > > > # 208 "/c/wfg/tip/arch/x86/include/asm/bitops.h" 1 > > > > bts $1, 8(%eax); setc %dl #,, c > > > > > > That compiler doesn't appear to have asm goto support, so we fall back > > > to the code we already knew worked :-) > > > > I'm using 4.7.2 with randconfig testing, which has asm goto support, and > > I haven't seen this crash yet. > > > > Unless my testing is off it might be a bug in GCC 4.8, or a pre-existing > > bug gets exposed by GCC 4.8. > > And as it happens, just a few hours later I hit a very similar crash, this > time compiled with both 4.7.3 and 4.7.2! (config attached) > > This has a weird-x86-arch tuning knob as well: > > CONFIG_MGEODE_LX=y > > So I think we might need to turn off asm goto for all things 32-bit x86.
Hm, 32 bit x86... I built 4.8.1 yesterday, so can now build x86_64 tip, but I suspect I'll not be the only one with a compiler that goes belly up. net/sunrpc/xprtsock.c: In function ‘xs_setup_tcp’: net/sunrpc/xprtsock.c:2844:1: internal compiler error: in move_insn, at haifa-sched.c:2353 gcc-4.6.2 (opensuse 12.1) has happily chewed up humongous piles of source, but finds this asm goto stuff to be toxic. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
