From: Boqun Feng <boqun.feng@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Boqun Feng <boqun.feng@gmail.com>
Subject: [RFC tip/locking/lockdep v4 09/17] lockdep: Add recursive read locks into dependency graph
Date: Tue, 9 Jan 2018 22:38:52 +0800 [thread overview]
Message-ID: <20180109143900.27475-10-boqun.feng@gmail.com> (raw)
In-Reply-To: <20180109143900.27475-1-boqun.feng@gmail.com>
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 | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index c7b1273a044a..36d0931e3b92 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2033,16 +2033,6 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
if (!check_prev_add_irq(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?
*
@@ -2146,11 +2136,7 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
int 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) {
+ if (hlock->check) {
int ret = check_prev_add(curr, hlock, next, distance, &trace, save_trace);
if (!ret)
return 0;
--
2.15.1
next prev parent reply other threads:[~2018-01-09 14:37 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-09 14:38 [RFC tip/locking/lockdep v4 00/17] lockdep: Support deadlock detection for recursive read locks Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 01/17] lockdep: Demagic the return value of BFS Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 02/17] lockdep: Make __bfs() visit every dependency until a match Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 03/17] lockdep: Redefine LOCK_*_STATE* bits Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 04/17] lockdep: Introduce lock_list::dep Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 05/17] lockdep: Extend __bfs() to work with multiple kinds of dependencies Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 06/17] lockdep: Support deadlock detection for recursive read in check_noncircular() Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 07/17] lockdep: Adjust check_redundant() for recursive read change Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 08/17] lockdep: Fix recursive read lock related safe->unsafe detection Boqun Feng
2018-01-09 14:38 ` Boqun Feng [this message]
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 10/17] lockdep/selftest: Add a R-L/L-W test case specific to chain cache behavior Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 11/17] lockdep: Take read/write status in consideration when generate chainkey Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 12/17] lockdep/selftest: Unleash irq_read_recursion2 and add more Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 13/17] lockdep/selftest: Add more recursive read related test cases Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 14/17] Revert "locking/lockdep/selftests: Fix mixed read-write ABBA tests" Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 15/17] lockdep: Reduce the size of lock_list Boqun Feng
2018-01-09 14:38 ` [RFC tip/locking/lockdep v4 16/17] lockdep: Documention for recursive read lock detection reasoning Boqun Feng
2018-01-25 1:05 ` Randy Dunlap
2018-01-25 1:40 ` Boqun Feng
2018-01-09 14:39 ` [RFC tip/locking/lockdep v4 17/17] MAINTAINERS: Add myself as a LOCKING PRIMITIVES reviewer Boqun Feng
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