locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro
authorWaiman Long <longman@redhat.com>
Thu, 4 Apr 2019 17:43:15 +0000 (13:43 -0400)
committerIngo Molnar <mingo@kernel.org>
Wed, 10 Apr 2019 08:56:03 +0000 (10:56 +0200)
commit3b4ba6643d26a95e08067fca9a5da1828f9afabf
treefad9ad6b108aec17dcd0b2b9da672697b84bd1d3
parenta68e2c4c637918da47b3aa270051545cff7d8245
locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro

Currently, the DEBUG_RWSEMS_WARN_ON() macro just dumps a stack trace
when the rwsem isn't in the right state. It does not show the actual
states of the rwsem. This may not be that helpful in the debugging
process.

Enhance the DEBUG_RWSEMS_WARN_ON() macro to also show the current
content of the rwsem count and owner fields to give more information
about what is wrong with the rwsem. The debug_locks_off() function is
called as is done inside DEBUG_LOCKS_WARN_ON().

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20190404174320.22416-7-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/locking/rwsem.c
kernel/locking/rwsem.h