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author | Boqun Feng <boqun.feng@gmail.com> | 2020-08-07 15:42:31 +0800 |
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committer | Peter Zijlstra <peterz@infradead.org> | 2020-08-26 12:42:06 +0200 |
commit | 621c9dac0eea7607cb9a57cc9ba47fbcd4e644c9 (patch) | |
tree | 481859afdd4eaed5252b5c11f6391cea4c87efcc | |
parent | f08e3888574d490b31481eef6d84c61bedba7a47 (diff) | |
download | linux-621c9dac0eea7607cb9a57cc9ba47fbcd4e644c9.tar.bz2 |
lockdep: Add recursive read locks into dependency graph
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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200807074238.1632519-13-boqun.feng@gmail.com
-rw-r--r-- | kernel/locking/lockdep.c | 19 |
1 files changed, 2 insertions, 17 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 6644974a4f5a..b87766e080f5 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2809,16 +2809,6 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, 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? * * (this may occur even though this is a new chain: consider @@ -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; |