Messages in this thread Patch in this message | | | From | Boqun Feng <> | Subject | [RFC v7 12/19] lockdep: Add recursive read locks into dependency graph | Date | Fri, 7 Aug 2020 15:42:31 +0800 |
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Since we have all the fundamental to handle recursive read locks, we now add them into the dependency graph.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com> --- kernel/locking/lockdep.c | 19 ++----------------- 1 file changed, 2 insertions(+), 17 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 040509667798..867199c4b85d 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2808,16 +2808,6 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, if (!check_irq_usage(curr, prev, next)) return 0; - /* - * For recursive read-locks we do all the dependency checks, - * but we dont store read-triggered dependencies (only - * write-triggered dependencies). This ensures that only the - * write-side dependencies matter, and that if for example a - * write-lock never takes any other locks, then the reads are - * equivalent to a NOP. - */ - if (next->read == 2 || prev->read == 2) - return 1; /* * Is the <prev> -> <next> dependency already present? * @@ -2935,13 +2925,8 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) u16 distance = curr->lockdep_depth - depth + 1; hlock = curr->held_locks + depth - 1; - /* - * Only non-recursive-read entries get new dependencies - * added: - */ - if (hlock->read != 2 && hlock->check) { - int ret = check_prev_add(curr, hlock, next, distance, - &trace); + if (hlock->check) { + int ret = check_prev_add(curr, hlock, next, distance, &trace); if (!ret) return 0; -- 2.28.0
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