[V2,1/7] locking/lockdep: Add Kconfig option for bit spinlocks
diff mbox series

Message ID 20190801010943.975240672@linutronix.de
State New
Headers show
  • fs: Substitute bit-spinlocks for PREEMPT_RT and debugging
Related show

Commit Message

Thomas Gleixner Aug. 1, 2019, 1:01 a.m. UTC
Some usage sites of bit spinlocks have a substitution with regular
spinlocks which depends on CONFIG_PREEMPT_RT. But this substitution can
also be used to expose these locks to the regular lock debugging
infrastructure, e.g. lockdep.

As this increases the size of affected data structures significantly this
is guarded by a separate Kconfig switch.

Note, that only the bit spinlocks which have a substitution implemented
will be covered by this. All other bit spinlocks evade lock debugging as

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
 lib/Kconfig.debug |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff mbox series

--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1201,6 +1201,16 @@  config DEBUG_RWSEMS
 	  This debugging feature allows mismatched rw semaphore locks
 	  and unlocks to be detected and reported.
+	bool "Bit spinlock debugging"
+	depends on DEBUG_SPINLOCK
+	help
+	  This debugging feature substitutes bit spinlocks in some use
+	  cases, e.g. buffer head, zram, with with regular spinlocks so
+	  these locks are exposed to lock debugging features.
+	  Not all bit spinlocks are covered by this.
 	bool "Lock debugging: detect incorrect freeing of live locks"