Messages in this thread | | | Date | Wed, 30 Mar 2011 10:34:28 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH v2] ubifs: fix kconfig dependency warning |
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On 3/30/2011 1:12 AM, Artem Bityutskiy wrote: > On Tue, 2011-03-29 at 08:48 -0700, Randy Dunlap wrote: >> On Tue, 29 Mar 2011 18:04:15 +0300 Artem Bityutskiy wrote: >> >>> On Tue, 2011-03-29 at 08:01 -0700, Randy Dunlap wrote: >>>> On 03/29/11 00:02, Artem Bityutskiy wrote: >>>>> On Mon, 2011-03-28 at 13:40 -0700, Randy Dunlap wrote: >>>>>> From: Randy Dunlap<randy.dunlap@oracle.com> >>>>>> >>>>>> Fix another kconfig dependency warning, this time in ubifs. >>>>>> >>>>>> warning: (UBIFS_FS_DEBUG&& LOCKDEP&& LATENCYTOP) selects KALLSYMS_ALL which has unmet direct dependencies (DEBUG_KERNEL&& KALLSYMS) >>>>>> >>>>>> Without this patch, we can have: >>>>>> # CONFIG_KALLSYMS is not set >>>>>> CONFIG_KALLSYMS_ALL=y >>>>>> which is useless (does nothing unless KALLSYMS is enabled). >>>>>> >>>>>> However, ubifs builds successfully with or without this patch, >>>>>> and it builds with this line completely deleted, >>>>>> so what was this 'select' for? Just developer convenience? >>>>> >>>>> Well, here is the idea. You can compile UBIFS with debugging and without >>>>> debugging. Without debugging the resulting ubifs.ko is much smaller, so >>>>> some embedded people prefer it this way. >>>>> >>>>> If you select debugging support, then we'll compile it a lot of >>>>> assertions, self-checks, test-modes, extra error messages with detailed >>>>> dumps. And we want to see stackdumps when errors or problems happen, >>>>> this is why we select KALLSYMS_ALL. >>>>> >>>>> So I guess instead we should do: >>>>> >>>>> select KALLSYMS >>>>> select KALLSYMS_ALL >>>> >>>> Yes, that should do it. Thanks for the explanation. >>> >>> Will you submit a patch? Alternatively, I can make it myself. What is >>> your preference? >> >> Here's an updated patch. But since KALLSYMS_ALL depends on DEBUG_KERNEL, >> the lines above aren't quite sufficient and I don't care to select >> DEBUG_KERNEL. > > What is the real difference between KALLSYMS_ALL and KALLSYMS? It looks > like for stack dumps KALLSYMS is enough. The Kconfig help text is not > very helpful. And when I look at the help text of > CONFIG_KALLSYMS_EXTRA_PASS I get feeling that this area needs some > clean-up work.
Yes, KALLSYMS is enough for most of us.
You can see what KALLSYMS_ALL does by looking at scripts/kallsyms.c, the --all-symbols option:
> /* if --all-symbols is not specified, then symbols outside the text > * and inittext sections are discarded */
> Anyway, any idea why we wouldn't just kill KALLSYMS_ALL by merging it > with KALLSYMS?
KALLSYMS_ALL probably generates noise for most use cases.
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