Messages in this thread | | | Date | Tue, 7 Jan 2003 16:58:38 -0500 | From | Daniel Jacobowitz <> | Subject | Re: Why do some net drivers require __OPTIMIZE__? |
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On Tue, Jan 07, 2003 at 02:33:07PM +0000, Alex Bennee wrote: > On Mon, 2003-01-06 at 15:36, Alan Cox wrote: > > > Does anybody know the history behind those lines? Do they serve any > > > purpose now or in the past? Should I be nervous about compiling the > > > kernel at a *lower* than normal optimization level? After all > > > optimizations are generally processor specific and shouldn't affect the > > > meaning of the C. > > > > Some of our inline and asm blocks assume things like optimisation. Killing > > that check and adding -finline-functions ought to be enough to get what > > you expect. > > It appears to go deeper than a few network drivers. Droping to -O0 > breaks a host of other sections (ipc, sockets etc.) for less than > obvious reasons. The only source files that seem to depend on the > __OPTIMIZE__ define are a few of the other drivers and the byteswap > macros. > > I'll investigate the gcc pages to see if there is anyway to allow > optimisation without the out-of-order stuff that makes tracing the start > up so hard. *sigh*
Try -O1; it's much better for debugging in general.
> I assume I can't drop the -fomit-frame-pointer for the same reason > (inline and asm blocks assuming register assigment?).
Shouldn't matter.
> On a related note should enabling -g on the kernel CFLAGS be ok? For > some reason vmlinux kernels compiled with -g (even after being stripped) > seem to break the bootmem allocator on my setup. I'm trying to track > down if this is due to some linker weirdness due to the symbol table > being bigger than physical memory even though its not actually being > loaded into the system.
It should be OK; it sounds like a problem with the loader you're using, at a guess.
-- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer - 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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