Messages in this thread | | | From | Waiman Long <> | Subject | Re: [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list | Date | Tue, 25 May 2021 10:17:57 -0400 |
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On 5/24/21 6:41 PM, Randy Dunlap wrote: > Some arches (um, sparc64, riscv, xtensa) cause a Kconfig warning for > LOCKDEP. > These arch-es select LOCKDEP_SUPPORT but they are not listed as one > of the arch-es that LOCKDEP depends on. > > Since (16) arch-es define the Kconfig symbol LOCKDEP_SUPPORT if they > intend to have LOCKDEP support, replace the awkward list of > arch-es that LOCKDEP depends on with the LOCKDEP_SUPPORT symbol. > > But wait. LOCKDEP_SUPPORT is included in LOCK_DEBUGGING_SUPPORT, > which is already a dependency here, so LOCKDEP_SUPPORT is redundant > and not needed. > That leaves the FRAME_POINTER dependency, but it is part of an > expression like this: > depends on (A && B) && (FRAME_POINTER || B') > where B' is a dependency of B so if B is true then B' is true > and the value of FRAME_POINTER does not matter. > Thus we can also delete the FRAME_POINTER dependency. > > Fixes this kconfig warning: (for um, sparc64, riscv, xtensa) > > WARNING: unmet direct dependencies detected for LOCKDEP > Depends on [n]: DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] && (FRAME_POINTER [=n] || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86) > Selected by [y]: > - PROVE_LOCKING [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] > - LOCK_STAT [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] > - DEBUG_LOCK_ALLOC [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] > > Link to v1: https://lore.kernel.org/lkml/20210517034430.9569-1-rdunlap@infradead.org/ > > Fixes: 7d37cb2c912d ("lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS") > Signed-off-by: Randy Dunlap <rdunlap@infradead.org> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Will Deacon <will@kernel.org> > Cc: Waiman Long <longman@redhat.com> > Cc: Boqun Feng <boqun.feng@gmail.com> > Cc: Chris Zankel <chris@zankel.net> > Cc: Max Filippov <jcmvbkbc@gmail.com> > Cc: linux-xtensa@linux-xtensa.org > Cc: Johannes Berg <johannes@sipsolutions.net> > Cc: Jeff Dike <jdike@addtoit.com> > Cc: Richard Weinberger <richard@nod.at> > Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> > Cc: linux-um@lists.infradead.org > Cc: Julian Braha <julianbraha@gmail.com> > Cc: linux-arch@vger.kernel.org > --- > @Julian: please take a look. I'm a little concerned about the > FRAME_POINTER dependency going away when our 2 patches are combined. > > v2: drop depends on LOCKDEP_SUPPORT for LOCKDEP; the use of > LOCK_DEBUGGING_SUPPORT already covers that dependency; > drop FRAME_POINTER dependency (thanks to Waiman Long > for both of these suggestions) > v2: add CC: to linux-arch > > lib/Kconfig.debug | 1 - > 1 file changed, 1 deletion(-) > > --- linux-next-20210524.orig/lib/Kconfig.debug > +++ linux-next-20210524/lib/Kconfig.debug > @@ -1383,7 +1383,6 @@ config LOCKDEP > bool > depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT > select STACKTRACE > - depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86 > select KALLSYMS > select KALLSYMS_ALL > > Acked-by: Waiman Long <longman@redhat.com>
Cheers, Longman
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