Messages in this thread | | | Date | Tue, 30 Nov 2010 17:31:06 +0800 | From | Américo Wang <> | Subject | Re: [PATCH] Built kernel without -O2 option |
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On Mon, Nov 29, 2010 at 11:12:16AM +0100, Mark Wielaard wrote: >On Mon, 2010-11-29 at 10:59 +0100, Andi Kleen wrote: >> Hui Zhu <teawater@gmail.com> writes: >> >> > Now, there are a lot of ways to debug the Linux kernel with GDB, like >> > qemu, kgtp or kgdb and so on. >> > But the developer more like add a printk. It have a lot of reason, a big one is: >> > (gdb) p ret >> > $3 = <value optimized out> >> > And the code execution order is not right. >> >> Really the right place to fix a lot of this would be gcc (and perhaps >> gdb). I suspect with some careful work the debugging experience >> for -O2 could be improved a lot. >> I also believe the latest gccs already have improvements in this area. > >The VTA branch was merged for GCC 4.5 >http://gcc.gnu.org/wiki/Var_Tracking_Assignments >Which helps a lot with generating dwarf for previously "optimized out" >values. There were also a couple of papers on generating even better >debuginfo at the recent GCC Summit: http://gcc.gnu.org/wiki/summit2010 > >Jakub Jelínek, Improving debug info for optimized away parameters >http://gcc.gnu.org/wiki/summit2010?action=AttachFile&do=get&target=jelinek.pdf >Alexandre Oliva, Consistent Views at Recommended Breakpoints >http://gcc.gnu.org/wiki/summit2010?action=AttachFile&do=get&target=oliva.pdf >
Cool! It would be much more convenient if this is solved by gcc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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