Re: [PATCH] LOCKDEP: use depends on LOCKDEP_SUPPORT instead of $ARCH list
From: Waiman Long
Date: Tue May 25 2021 - 10:16:02 EST
On 5/25/21 12:18 AM, Randy Dunlap wrote:
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)
Right. I am fine with that.
Thanks,
Longman