From: Boqun Feng <boqun.feng@gmail.com> To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, Andrea Parri <parri.andrea@gmail.com>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>, Boqun Feng <boqun.feng@gmail.com>, Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org (open list:DOCUMENTATION) Subject: [RFC tip/locking/lockdep v6 04/20] lockdep: Redefine LOCK_*_STATE* bits Date: Wed, 11 Apr 2018 21:50:54 +0800 [thread overview] Message-ID: <20180411135110.9217-5-boqun.feng@gmail.com> (raw) In-Reply-To: <20180411135110.9217-1-boqun.feng@gmail.com> There are three types of lock acquisitions: write, non-recursive read and recursive read, among which write locks and non-recursive read locks have no difference from a viewpoint for deadlock detections, because a write acquisition of the corresponding lock on an independent CPU or task makes a non-recursive read lock act as a write lock in the sense of deadlock. So we could treat them as the same type (named as "non-recursive lock") in lockdep. As in the irq lock inversion detection (safe->unsafe deadlock detection), we used to differ write lock with read lock (non-recursive and recursive ones), such a classification could be improved as non-recursive read lock behaves the same as write lock, so this patch redefines the meanings of LOCK_{USED_IN, ENABLED}_STATE*. old: LOCK_* : stands for write lock LOCK_*_READ: stands for read lock(non-recursive and recursive) new: LOCK_* : stands for non-recursive(write lock and non-recursive read lock) LOCK_*_RR: stands for recursive read lock Such a change is needed for a future improvement on recursive read related irq inversion deadlock detection. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> --- Documentation/locking/lockdep-design.txt | 6 +++--- kernel/locking/lockdep.c | 28 ++++++++++++++-------------- kernel/locking/lockdep_internals.h | 16 ++++++++-------- kernel/locking/lockdep_proc.c | 12 ++++++------ 4 files changed, 31 insertions(+), 31 deletions(-) diff --git a/Documentation/locking/lockdep-design.txt b/Documentation/locking/lockdep-design.txt index 6bb9e90e2c4f..53ede30ce16d 100644 --- a/Documentation/locking/lockdep-design.txt +++ b/Documentation/locking/lockdep-design.txt @@ -30,9 +30,9 @@ State The validator tracks lock-class usage history into 4n + 1 separate state bits: - 'ever held in STATE context' -- 'ever held as readlock in STATE context' +- 'ever held as recursive readlock in STATE context' - 'ever held with STATE enabled' -- 'ever held as readlock with STATE enabled' +- 'ever held as recurisve readlock with STATE enabled' Where STATE can be either one of (kernel/locking/lockdep_states.h) - hardirq @@ -51,7 +51,7 @@ locking error messages, inside curlies. A contrived example: (&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24 -The bit position indicates STATE, STATE-read, for each of the states listed +The bit position indicates STATE, STATE-RR, for each of the states listed above, and the character displayed in each indicates: '.' acquired while irqs disabled and not in irq context diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index f39a071ef0a8..14af2327b52a 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -448,10 +448,10 @@ DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats); */ #define __USAGE(__STATE) \ - [LOCK_USED_IN_##__STATE] = "IN-"__stringify(__STATE)"-W", \ - [LOCK_ENABLED_##__STATE] = __stringify(__STATE)"-ON-W", \ - [LOCK_USED_IN_##__STATE##_READ] = "IN-"__stringify(__STATE)"-R",\ - [LOCK_ENABLED_##__STATE##_READ] = __stringify(__STATE)"-ON-R", + [LOCK_USED_IN_##__STATE] = "IN-"__stringify(__STATE), \ + [LOCK_ENABLED_##__STATE] = __stringify(__STATE)"-ON", \ + [LOCK_USED_IN_##__STATE##_RR] = "IN-"__stringify(__STATE)"-RR", \ + [LOCK_ENABLED_##__STATE##_RR] = __stringify(__STATE)"-ON-RR", static const char *usage_str[] = { @@ -492,7 +492,7 @@ void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS]) #define LOCKDEP_STATE(__STATE) \ usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE); \ - usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_READ); + usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_RR); #include "lockdep_states.h" #undef LOCKDEP_STATE @@ -1645,7 +1645,7 @@ static const char *state_names[] = { static const char *state_rnames[] = { #define LOCKDEP_STATE(__STATE) \ - __stringify(__STATE)"-READ", + __stringify(__STATE)"-RR", #include "lockdep_states.h" #undef LOCKDEP_STATE }; @@ -3039,14 +3039,14 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) * mark the lock as used in these contexts: */ if (!hlock->trylock) { - if (hlock->read) { + if (hlock->read == 2) { if (curr->hardirq_context) if (!mark_lock(curr, hlock, - LOCK_USED_IN_HARDIRQ_READ)) + LOCK_USED_IN_HARDIRQ_RR)) return 0; if (curr->softirq_context) if (!mark_lock(curr, hlock, - LOCK_USED_IN_SOFTIRQ_READ)) + LOCK_USED_IN_SOFTIRQ_RR)) return 0; } else { if (curr->hardirq_context) @@ -3058,13 +3058,13 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) } } if (!hlock->hardirqs_off) { - if (hlock->read) { + if (hlock->read == 2) { if (!mark_lock(curr, hlock, - LOCK_ENABLED_HARDIRQ_READ)) + LOCK_ENABLED_HARDIRQ_RR)) return 0; if (curr->softirqs_enabled) if (!mark_lock(curr, hlock, - LOCK_ENABLED_SOFTIRQ_READ)) + LOCK_ENABLED_SOFTIRQ_RR)) return 0; } else { if (!mark_lock(curr, hlock, @@ -3170,9 +3170,9 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, switch (new_bit) { #define LOCKDEP_STATE(__STATE) \ case LOCK_USED_IN_##__STATE: \ - case LOCK_USED_IN_##__STATE##_READ: \ + case LOCK_USED_IN_##__STATE##_RR: \ case LOCK_ENABLED_##__STATE: \ - case LOCK_ENABLED_##__STATE##_READ: + case LOCK_ENABLED_##__STATE##_RR: #include "lockdep_states.h" #undef LOCKDEP_STATE ret = mark_lock_irq(curr, this, new_bit); diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index d459d624ba2a..93002d337936 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -13,9 +13,9 @@ enum lock_usage_bit { #define LOCKDEP_STATE(__STATE) \ LOCK_USED_IN_##__STATE, \ - LOCK_USED_IN_##__STATE##_READ, \ + LOCK_USED_IN_##__STATE##_RR, \ LOCK_ENABLED_##__STATE, \ - LOCK_ENABLED_##__STATE##_READ, + LOCK_ENABLED_##__STATE##_RR, #include "lockdep_states.h" #undef LOCKDEP_STATE LOCK_USED, @@ -30,9 +30,9 @@ enum lock_usage_bit { enum { #define LOCKDEP_STATE(__STATE) \ __LOCKF(USED_IN_##__STATE) \ - __LOCKF(USED_IN_##__STATE##_READ) \ + __LOCKF(USED_IN_##__STATE##_RR) \ __LOCKF(ENABLED_##__STATE) \ - __LOCKF(ENABLED_##__STATE##_READ) + __LOCKF(ENABLED_##__STATE##_RR) #include "lockdep_states.h" #undef LOCKDEP_STATE __LOCKF(USED) @@ -41,10 +41,10 @@ enum { #define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ) #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ) -#define LOCKF_ENABLED_IRQ_READ \ - (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ) -#define LOCKF_USED_IN_IRQ_READ \ - (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ) +#define LOCKF_ENABLED_IRQ_RR \ + (LOCKF_ENABLED_HARDIRQ_RR | LOCKF_ENABLED_SOFTIRQ_RR) +#define LOCKF_USED_IN_IRQ_RR \ + (LOCKF_USED_IN_HARDIRQ_RR | LOCKF_USED_IN_SOFTIRQ_RR) /* * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text, diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index ad69bbc9bd28..630a6bc6e24c 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -252,17 +252,17 @@ static int lockdep_stats_show(struct seq_file *m, void *v) nr_hardirq_safe++; if (class->usage_mask & LOCKF_ENABLED_HARDIRQ) nr_hardirq_unsafe++; - if (class->usage_mask & LOCKF_USED_IN_IRQ_READ) + if (class->usage_mask & LOCKF_USED_IN_IRQ_RR) nr_irq_read_safe++; - if (class->usage_mask & LOCKF_ENABLED_IRQ_READ) + if (class->usage_mask & LOCKF_ENABLED_IRQ_RR) nr_irq_read_unsafe++; - if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) + if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_RR) nr_softirq_read_safe++; - if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ) + if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_RR) nr_softirq_read_unsafe++; - if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) + if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_RR) nr_hardirq_read_safe++; - if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ) + if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_RR) nr_hardirq_read_unsafe++; #ifdef CONFIG_PROVE_LOCKING -- 2.16.2
next prev parent reply other threads:[~2018-04-11 13:47 UTC|newest] Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-04-11 13:50 [RFC tip/locking/lockdep v6 00/20] lockdep: Support deadlock detection for recursive read locks Boqun Feng 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 01/20] lockdep/Documention: Recursive read lock detection reasoning Boqun Feng 2018-04-15 0:38 ` Randy Dunlap 2018-04-16 6:29 ` Boqun Feng 2018-04-27 13:50 ` Boqun Feng 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 02/20] lockdep: Demagic the return value of BFS Boqun Feng 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 03/20] lockdep: Make __bfs() visit every dependency until a match Boqun Feng 2018-04-11 13:50 ` Boqun Feng [this message] 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 05/20] lockdep: Reduce the size of lock_list::distance Boqun Feng 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 06/20] lockdep: Introduce lock_list::dep Boqun Feng 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 07/20] lockdep: Extend __bfs() to work with multiple types of dependencies Boqun Feng 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 08/20] lockdep: Make __bfs(.match) return bool Boqun Feng 2018-04-11 13:50 ` [RFC tip/locking/lockdep v6 09/20] lockdep: Support deadlock detection for recursive read locks in check_noncircular() Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 10/20] lockdep: Adjust check_redundant() for recursive read change Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 11/20] lockdep: Fix recursive read lock related safe->unsafe detection Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 12/20] lockdep: Add recursive read locks into dependency graph Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 13/20] lockdep/selftest: Add a R-L/L-W test case specific to chain cache behavior Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 14/20] lockdep: Take read/write status in consideration when generate chainkey Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 15/20] lockdep/selftest: Unleash irq_read_recursion2 and add more Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 16/20] lockdep/selftest: Add more recursive read related test cases Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 17/20] Revert "locking/lockdep/selftests: Fix mixed read-write ABBA tests" Boqun Feng 2018-04-11 13:51 ` [RFC tip/locking/lockdep v6 18/20] MAINTAINERS: Add myself as a LOCKING PRIMITIVES reviewer Boqun Feng 2018-04-11 13:56 ` [RFC tip/locking/lockdep v6 19/20] rcu: Equip sleepable RCU with lockdep dependency graph checks Boqun Feng 2018-04-11 18:57 ` Paul E. McKenney 2018-04-12 2:12 ` Boqun Feng 2018-04-12 9:12 ` Peter Zijlstra 2018-04-13 13:24 ` Boqun Feng 2018-04-11 13:57 ` [RFC tip/locking/lockdep v6 20/20] lockdep/selftest: Add a test case for SRCU Boqun Feng
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