* Re: [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list
2021-05-24 22:41 [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list Randy Dunlap
@ 2021-05-25 3:31 ` Julian Braha
2021-05-25 7:08 ` Peter Zijlstra
2021-05-25 7:07 ` Peter Zijlstra
` (2 subsequent siblings)
3 siblings, 1 reply; 6+ messages in thread
From: Julian Braha @ 2021-05-25 3:31 UTC (permalink / raw)
To: linux-kernel, Randy Dunlap, Peter Zijlstra
Cc: Ingo Molnar, Will Deacon, Waiman Long, Boqun Feng, Chris Zankel,
Max Filippov, linux-xtensa, Johannes Berg, Jeff Dike,
Richard Weinberger, Anton Ivanov, linux-um, linux-arch
Hi Randy,
It seems I introduced a new unmet dependency bug
in my attempt to fix one :/
Anyway, I don't see why the dependency on FRAME_POINTER
was necessary in the first place, so LGTM.
- Julian Braha
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list
2021-05-25 3:31 ` Julian Braha
@ 2021-05-25 7:08 ` Peter Zijlstra
0 siblings, 0 replies; 6+ messages in thread
From: Peter Zijlstra @ 2021-05-25 7:08 UTC (permalink / raw)
To: Julian Braha
Cc: linux-kernel, Randy Dunlap, Ingo Molnar, Will Deacon,
Waiman Long, Boqun Feng, Chris Zankel, Max Filippov,
linux-xtensa, Johannes Berg, Jeff Dike, Richard Weinberger,
Anton Ivanov, linux-um, linux-arch
On Mon, May 24, 2021 at 11:31:22PM -0400, Julian Braha wrote:
> Hi Randy,
>
> It seems I introduced a new unmet dependency bug
> in my attempt to fix one :/
>
> Anyway, I don't see why the dependency on FRAME_POINTER
> was necessary in the first place, so LGTM.
It might have been an attempt at ensuring sane backtraces; but I didn't
dig into the history of the thing. Either way around, it's fairly
out-dated if that was indeed the case.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list
2021-05-24 22:41 [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list Randy Dunlap
2021-05-25 3:31 ` Julian Braha
@ 2021-05-25 7:07 ` Peter Zijlstra
2021-05-25 14:17 ` Waiman Long
2021-05-31 10:40 ` [tip: locking/core] locking/lockdep: Reduce " tip-bot2 for Randy Dunlap
3 siblings, 0 replies; 6+ messages in thread
From: Peter Zijlstra @ 2021-05-25 7:07 UTC (permalink / raw)
To: Randy Dunlap
Cc: linux-kernel, Ingo Molnar, Will Deacon, Waiman Long, Boqun Feng,
Chris Zankel, Max Filippov, linux-xtensa, Johannes Berg,
Jeff Dike, Richard Weinberger, Anton Ivanov, linux-um,
Julian Braha, linux-arch
On Mon, May 24, 2021 at 03:41:50PM -0700, 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>
Thanks!
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list
2021-05-24 22:41 [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list Randy Dunlap
2021-05-25 3:31 ` Julian Braha
2021-05-25 7:07 ` Peter Zijlstra
@ 2021-05-25 14:17 ` Waiman Long
2021-05-31 10:40 ` [tip: locking/core] locking/lockdep: Reduce " tip-bot2 for Randy Dunlap
3 siblings, 0 replies; 6+ messages in thread
From: Waiman Long @ 2021-05-25 14:17 UTC (permalink / raw)
To: Randy Dunlap, linux-kernel
Cc: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng,
Chris Zankel, Max Filippov, linux-xtensa, Johannes Berg,
Jeff Dike, Richard Weinberger, Anton Ivanov, linux-um,
Julian Braha, linux-arch
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
^ permalink raw reply [flat|nested] 6+ messages in thread* [tip: locking/core] locking/lockdep: Reduce LOCKDEP dependency list
2021-05-24 22:41 [PATCH v2] LOCKDEP: reduce LOCKDEP dependency list Randy Dunlap
` (2 preceding siblings ...)
2021-05-25 14:17 ` Waiman Long
@ 2021-05-31 10:40 ` tip-bot2 for Randy Dunlap
3 siblings, 0 replies; 6+ messages in thread
From: tip-bot2 for Randy Dunlap @ 2021-05-31 10:40 UTC (permalink / raw)
To: linux-tip-commits
Cc: Randy Dunlap, Peter Zijlstra (Intel), Waiman Long, x86, linux-kernel
The following commit has been merged into the locking/core branch of tip:
Commit-ID: b8e00abe7d9fe21dd13609e2e3a707e38902b105
Gitweb: https://git.kernel.org/tip/b8e00abe7d9fe21dd13609e2e3a707e38902b105
Author: Randy Dunlap <rdunlap@infradead.org>
AuthorDate: Mon, 24 May 2021 15:41:50 -07:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 31 May 2021 10:14:54 +02:00
locking/lockdep: Reduce LOCKDEP dependency list
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]
Fixes: 7d37cb2c912d ("lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20210524224150.8009-1-rdunlap@infradead.org
---
lib/Kconfig.debug | 1 -
1 file changed, 1 deletion(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 678c139..1e1bd6f 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1372,7 +1372,6 @@ 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
^ permalink raw reply related [flat|nested] 6+ messages in thread