Messages in this thread | | | Subject | Re: [PATCH] LOCKDEP: use depends on LOCKDEP_SUPPORT instead of $ARCH list | From | Randy Dunlap <> | Date | Mon, 24 May 2021 21:18:26 -0700 |
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On 5/24/21 5:05 PM, Waiman Long wrote: > On 5/24/21 5:41 PM, Randy Dunlap wrote: >> On 5/24/21 2:31 PM, Randy Dunlap wrote: >>> On 5/24/21 2:04 PM, Waiman Long wrote: >>> >>>> Is it possible to just get rid of the 2nd depends-on statement? >>>> >>>> The 2nd depends-on line was introduced by commit 7d37cb2c912d ("lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTER"): >>> and I should have looked at that history too. Thanks. >>> >>> Yes, I agree, we can just delete that line... >>> >>> I'll send a v2 and copy the author of commit 7d37cb2c912d as well. >> Hm, as I review that commit, I have to wonder if the previous 'select' >> was correct (if we disregard the Kconfig warning). If so, then >> FRAME_POINTER is still wanted/needed for some arch-es. >> >> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug >> index 2779c29d9981..417c3d3e521b 100644 >> --- a/lib/Kconfig.debug >> +++ b/lib/Kconfig.debug >> @@ -1363,7 +1363,7 @@ config LOCKDEP >> bool >> depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT >> select STACKTRACE >> - select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86 <<<<<<<<<<< >> > AFAICS, enabling FRAME_POINTER is a debugging aid as it enable more precise stacktrace. However, not all archs want to enable FRAME_POINTER because of LOCKDEP. Now you are just letting users decide if they want FRAME_POINTER or not. Maybe you can modify the help text to mention that.
LOCKDEP doesn't have any user help text.
For FRAME_POINTER, when ARCH_WANT_FRAME_POINTERS + a few other conditions is met, it seems that the FRAME_POINTER help text is good enough IMO.
help If you say Y here the resulting kernel image will be slightly larger and slower, but it gives very useful debugging information in case of kernel bugs. (precise oopses/stacktraces/warnings)
-- ~Randy
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