On 11/25/24 13:29, Waiman Long wrote:
On 11/25/24 4:25 PM, Guenter Roeck wrote:
On 11/25/24 12:54, Waiman Long wrote:
On 11/25/24 3:23 PM, Guenter Roeck wrote:
On 11/25/24 12:06, Guenter Roeck wrote:
On 11/25/24 11:33, Waiman Long wrote:
[ ... ]
Fixing that finally gives me a clean run. Nevertheless, that makes me wonder:
Should I just disable CONFIG_PROVE_RAW_LOCK_NESTING for sparc runtime tests ?
If no one is tryng to ever enable PREEMPT_RT on SPARC, I suppose you could disable CONFIG_PROVE_RAW_LOCK_NESTING to avoid the trouble.
SGTM. I'll do that unless someone gives me a good reason to keep it enabled.
Actually it can not be disabled with a configuration flag. It is
automatically enabled. I'll have to disable PROVE_LOCKING to disable it.
config PROVE_RAW_LOCK_NESTING
bool <---- no longer user configurable
depends on PROVE_LOCKING
default y
help
Enable the raw_spinlock vs. spinlock nesting checks which ensure
that the lock nesting rules for PREEMPT_RT enabled kernels are
not violated.
I don't really like that, and I don't understand the logic behind it,
but it is what it is.
FWIW, the description of commit 560af5dc839 is misleading. It says "Enable
PROVE_RAW_LOCK_NESTING _by default_" (emphasis mine). That is not what the
commit does. It force-enables PROVE_RAW_LOCK_NESTING if PROVE_LOCKING is
enabled. It is all or nothing.
I think we can relax it by
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5d9eca035d47..bfdbd3fa2d29 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1399,7 +1399,7 @@ config PROVE_LOCKING
config PROVE_RAW_LOCK_NESTING
bool
depends on PROVE_LOCKING
- default y
+ default y if ARCH_SUPPORTS_RT
help
Enable the raw_spinlock vs. spinlock nesting checks which ensure
that the lock nesting rules for PREEMPT_RT enabled kernels are
Sebastian, what do you think?
depends on PROVE_LOCKING && ARCH_SUPPORTS_RT
seems to make more sense to me.
That will work too, but that will enforce that arches with no ARCH_SUPPORTS_RT will not be able to enable PROVE_RAW_LOCK_NESTING even if people want to try it out.
No architecture will be able to enable anything because "bool" has no
string associated with it. As mentioned before, it is all or nothing.
Otherwise I could just configure "CONFIG_PROVE_RAW_LOCK_NESTING=n"
for sparc and be done.
Guenter
