From: Byungchul Park <byungchul.park@lge.com> To: peterz@infradead.org, mingo@kernel.org Cc: tglx@linutronix.de, walken@google.com, boqun.feng@gmail.com, kirill@shutemov.name, linux-kernel@vger.kernel.org, linux-mm@kvack.org, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, npiggin@gmail.com Subject: [PATCH v5 03/13] lockdep: Add a function building a chain between two classes Date: Wed, 18 Jan 2017 22:17:29 +0900 [thread overview] Message-ID: <1484745459-2055-4-git-send-email-byungchul.park@lge.com> (raw) In-Reply-To: <1484745459-2055-1-git-send-email-byungchul.park@lge.com> Currently, add_chain_cache() should be used in the context where the hlock is owned since it might be racy. However, crossrelease needs to build a chain between two locks regardless of context. So this patch introduces a new function making it possible. Signed-off-by: Byungchul Park <byungchul.park@lge.com> --- kernel/locking/lockdep.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index a143eb4..2081c31 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2109,6 +2109,76 @@ static int check_no_collision(struct task_struct *curr, return 1; } +/* + * This is for building a chain between just two different classes, + * instead of adding a new hlock upon current, which is done by + * add_chain_cache(). + * + * This can be called in any context with two classes, while + * add_chain_cache() must be done within the lock owener's context + * since it uses hlock which might be racy in another context. + */ +static inline int add_chain_cache_classes(unsigned int prev, + unsigned int next, + unsigned int irq_context, + u64 chain_key) +{ + struct hlist_head *hash_head = chainhashentry(chain_key); + struct lock_chain *chain; + + /* + * Allocate a new chain entry from the static array, and add + * it to the hash: + */ + + /* + * We might need to take the graph lock, ensure we've got IRQs + * disabled to make this an IRQ-safe lock.. for recursion reasons + * lockdep won't complain about its own locking errors. + */ + if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) + return 0; + + if (unlikely(nr_lock_chains >= MAX_LOCKDEP_CHAINS)) { + if (!debug_locks_off_graph_unlock()) + return 0; + + print_lockdep_off("BUG: MAX_LOCKDEP_CHAINS too low!"); + dump_stack(); + return 0; + } + + chain = lock_chains + nr_lock_chains++; + chain->chain_key = chain_key; + chain->irq_context = irq_context; + chain->depth = 2; + if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) { + chain->base = nr_chain_hlocks; + nr_chain_hlocks += chain->depth; + chain_hlocks[chain->base] = prev - 1; + chain_hlocks[chain->base + 1] = next -1; + } +#ifdef CONFIG_DEBUG_LOCKDEP + /* + * Important for check_no_collision(). + */ + else { + if (!debug_locks_off_graph_unlock()) + return 0; + + print_lockdep_off("BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!"); + dump_stack(); + return 0; + } +#endif + + hlist_add_head_rcu(&chain->entry, hash_head); + debug_atomic_inc(chain_lookup_misses); + inc_chains(); + + return 1; +} + static inline int add_chain_cache(struct task_struct *curr, struct held_lock *hlock, u64 chain_key) -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Byungchul Park <byungchul.park@lge.com> To: peterz@infradead.org, mingo@kernel.org Cc: tglx@linutronix.de, walken@google.com, boqun.feng@gmail.com, kirill@shutemov.name, linux-kernel@vger.kernel.org, linux-mm@kvack.org, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, npiggin@gmail.com Subject: [PATCH v5 03/13] lockdep: Add a function building a chain between two classes Date: Wed, 18 Jan 2017 22:17:29 +0900 [thread overview] Message-ID: <1484745459-2055-4-git-send-email-byungchul.park@lge.com> (raw) In-Reply-To: <1484745459-2055-1-git-send-email-byungchul.park@lge.com> Currently, add_chain_cache() should be used in the context where the hlock is owned since it might be racy. However, crossrelease needs to build a chain between two locks regardless of context. So this patch introduces a new function making it possible. Signed-off-by: Byungchul Park <byungchul.park@lge.com> --- kernel/locking/lockdep.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index a143eb4..2081c31 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2109,6 +2109,76 @@ static int check_no_collision(struct task_struct *curr, return 1; } +/* + * This is for building a chain between just two different classes, + * instead of adding a new hlock upon current, which is done by + * add_chain_cache(). + * + * This can be called in any context with two classes, while + * add_chain_cache() must be done within the lock owener's context + * since it uses hlock which might be racy in another context. + */ +static inline int add_chain_cache_classes(unsigned int prev, + unsigned int next, + unsigned int irq_context, + u64 chain_key) +{ + struct hlist_head *hash_head = chainhashentry(chain_key); + struct lock_chain *chain; + + /* + * Allocate a new chain entry from the static array, and add + * it to the hash: + */ + + /* + * We might need to take the graph lock, ensure we've got IRQs + * disabled to make this an IRQ-safe lock.. for recursion reasons + * lockdep won't complain about its own locking errors. + */ + if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) + return 0; + + if (unlikely(nr_lock_chains >= MAX_LOCKDEP_CHAINS)) { + if (!debug_locks_off_graph_unlock()) + return 0; + + print_lockdep_off("BUG: MAX_LOCKDEP_CHAINS too low!"); + dump_stack(); + return 0; + } + + chain = lock_chains + nr_lock_chains++; + chain->chain_key = chain_key; + chain->irq_context = irq_context; + chain->depth = 2; + if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) { + chain->base = nr_chain_hlocks; + nr_chain_hlocks += chain->depth; + chain_hlocks[chain->base] = prev - 1; + chain_hlocks[chain->base + 1] = next -1; + } +#ifdef CONFIG_DEBUG_LOCKDEP + /* + * Important for check_no_collision(). + */ + else { + if (!debug_locks_off_graph_unlock()) + return 0; + + print_lockdep_off("BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!"); + dump_stack(); + return 0; + } +#endif + + hlist_add_head_rcu(&chain->entry, hash_head); + debug_atomic_inc(chain_lookup_misses); + inc_chains(); + + return 1; +} + static inline int add_chain_cache(struct task_struct *curr, struct held_lock *hlock, u64 chain_key) -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-01-18 13:18 UTC|newest] Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-01-18 13:17 [PATCH v5 00/13] lockdep: Implement crossrelease feature Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 01/13] lockdep: Refactor lookup_chain_cache() Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-19 9:16 ` Boqun Feng 2017-01-19 9:52 ` Byungchul Park 2017-01-19 9:52 ` Byungchul Park 2017-01-26 7:53 ` Byungchul Park 2017-01-26 7:53 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 02/13] lockdep: Fix wrong condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` Byungchul Park [this message] 2017-01-18 13:17 ` [PATCH v5 03/13] lockdep: Add a function building a chain between two classes Byungchul Park 2017-01-18 13:17 ` [PATCH v5 04/13] lockdep: Refactor save_trace() Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 05/13] lockdep: Pass a callback arg to check_prev_add() to handle stack_trace Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-26 7:43 ` Byungchul Park 2017-01-26 7:43 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 06/13] lockdep: Implement crossrelease feature Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-02-28 12:26 ` Peter Zijlstra 2017-02-28 12:26 ` Peter Zijlstra 2017-02-28 12:45 ` Peter Zijlstra 2017-02-28 12:45 ` Peter Zijlstra 2017-02-28 12:49 ` Peter Zijlstra 2017-02-28 12:49 ` Peter Zijlstra 2017-03-01 6:20 ` Byungchul Park 2017-03-01 6:20 ` Byungchul Park 2017-02-28 13:05 ` Peter Zijlstra 2017-02-28 13:05 ` Peter Zijlstra 2017-02-28 13:28 ` Byungchul Park 2017-02-28 13:28 ` Byungchul Park 2017-02-28 13:35 ` Peter Zijlstra 2017-02-28 13:35 ` Peter Zijlstra 2017-02-28 14:00 ` Byungchul Park 2017-02-28 14:00 ` Byungchul Park 2017-02-28 13:10 ` Peter Zijlstra 2017-02-28 13:10 ` Peter Zijlstra 2017-02-28 13:24 ` Byungchul Park 2017-02-28 13:24 ` Byungchul Park 2017-02-28 18:29 ` Peter Zijlstra 2017-02-28 18:29 ` Peter Zijlstra 2017-03-01 4:40 ` Byungchul Park 2017-03-01 4:40 ` Byungchul Park 2017-03-01 10:45 ` Peter Zijlstra 2017-03-01 10:45 ` Peter Zijlstra 2017-03-01 12:10 ` Byungchul Park 2017-03-01 12:10 ` Byungchul Park 2017-02-28 13:40 ` Peter Zijlstra 2017-02-28 13:40 ` Peter Zijlstra 2017-03-01 5:43 ` Byungchul Park 2017-03-01 5:43 ` Byungchul Park 2017-03-01 12:28 ` Peter Zijlstra 2017-03-01 12:28 ` Peter Zijlstra 2017-03-02 13:40 ` Peter Zijlstra 2017-03-02 13:40 ` Peter Zijlstra 2017-03-03 0:17 ` Byungchul Park 2017-03-03 0:17 ` Byungchul Park 2017-03-03 8:14 ` Peter Zijlstra 2017-03-03 8:14 ` Peter Zijlstra 2017-03-03 9:13 ` Peter Zijlstra 2017-03-03 9:13 ` Peter Zijlstra 2017-03-03 9:32 ` Peter Zijlstra 2017-03-03 9:32 ` Peter Zijlstra 2017-03-05 3:33 ` Byungchul Park 2017-03-05 3:33 ` Byungchul Park 2017-08-10 12:18 ` [tip:locking/core] locking/lockdep: Avoid creating redundant links tip-bot for Peter Zijlstra 2017-03-05 3:08 ` [PATCH v5 06/13] lockdep: Implement crossrelease feature Byungchul Park 2017-03-05 3:08 ` Byungchul Park 2017-03-07 11:42 ` Peter Zijlstra 2017-03-07 11:42 ` Peter Zijlstra 2017-03-03 0:39 ` Byungchul Park 2017-03-03 0:39 ` Byungchul Park 2017-02-28 15:49 ` Peter Zijlstra 2017-02-28 15:49 ` Peter Zijlstra 2017-03-01 5:17 ` Byungchul Park 2017-03-01 5:17 ` Byungchul Park 2017-03-01 6:18 ` Byungchul Park 2017-03-01 6:18 ` Byungchul Park 2017-03-02 2:52 ` Byungchul Park 2017-03-02 2:52 ` Byungchul Park 2017-02-28 18:15 ` Peter Zijlstra 2017-02-28 18:15 ` Peter Zijlstra 2017-03-01 7:21 ` Byungchul Park 2017-03-01 7:21 ` Byungchul Park 2017-03-01 10:43 ` Peter Zijlstra 2017-03-01 10:43 ` Peter Zijlstra 2017-03-01 12:27 ` Byungchul Park 2017-03-01 12:27 ` Byungchul Park 2017-03-02 4:20 ` Matthew Wilcox 2017-03-02 4:20 ` Matthew Wilcox 2017-03-02 4:45 ` byungchul.park 2017-03-02 4:45 ` byungchul.park 2017-03-02 14:39 ` Matthew Wilcox 2017-03-02 14:39 ` Matthew Wilcox 2017-03-02 23:50 ` Byungchul Park 2017-03-02 23:50 ` Byungchul Park 2017-03-05 8:01 ` Byungchul Park 2017-03-05 8:01 ` Byungchul Park 2017-03-14 7:36 ` Byungchul Park 2017-03-14 7:36 ` Byungchul Park 2017-03-02 13:41 ` Peter Zijlstra 2017-03-02 13:41 ` Peter Zijlstra 2017-03-02 23:43 ` Byungchul Park 2017-03-02 23:43 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 07/13] lockdep: Make print_circular_bug() aware of crossrelease Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 08/13] lockdep: Apply crossrelease to completions Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 09/13] pagemap.h: Remove trailing white space Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 10/13] lockdep: Apply crossrelease to PG_locked locks Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 11/13] lockdep: Apply lock_acquire(release) on __Set(__Clear)PageLocked Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 12/13] lockdep: Move data of CONFIG_LOCKDEP_PAGELOCK from page to page_ext Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-18 13:17 ` [PATCH v5 13/13] lockdep: Crossrelease feature documentation Byungchul Park 2017-01-18 13:17 ` Byungchul Park 2017-01-20 9:08 ` [REVISED DOCUMENT] " Byungchul Park 2017-01-20 9:08 ` Byungchul Park 2017-02-20 8:38 ` [PATCH v5 00/13] lockdep: Implement crossrelease feature Byungchul Park 2017-02-20 8:38 ` Byungchul Park
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