Messages in this thread | | | From | Waiman Long <> | Subject | [PATCH 0/2 v6] lockdep: add support for queued rwlock | Date | Tue, 29 Jul 2014 14:53:17 -0400 |
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v5->v6: - Unconditionally disallow the use of recursive read-lock in process context. - Promote read state 3 to 2 when in interrupt context instead of doing additional check in check_deadlock(). - Fix some comments in locking-selftest.c.
v4->v5: - Add patch 2 to update the locking selftest code to handle recursive read_lock correctly. Patch 1 has no change.
v3->v4: - Document the new read state and move the conditional compilation code to lockdep.h.
v2->v3: - Add a new read mode (3) for rwlock (used in lock_acquire_shared_cond_recursive()) to avoid conflict with other use cases of lock_acquire_shared_recursive().
v1->v2: - Use less conditional & make it easier to read
With the merging of qrwlock into 3.16, it was found that the btrfs filesystem hanged readily. A fix was devised and merged into rc2 and the use of recursive read_lock call was part of the problem.
This patch series addes code to the lockdep subsystem to catch this kind of recursive read_lock calls in kernel code. It also updates the locking selftest to handle recursive read_lock correctly so that it won't complain about test failures.
Waiman Long (2): locking/lockdep: Restrict the use of recursive read_lock() with qrwlock locking/selftest: Support queued rwlock
include/linux/lockdep.h | 10 +++++++++- kernel/locking/lockdep.c | 6 ++++++ lib/locking-selftest.c | 12 ++++++------ 3 files changed, 21 insertions(+), 7 deletions(-)
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