Commit-ID: 2212684adff79e2704a2792ff46682afb9246fc8 Gitweb: https://git.kernel.org/tip/2212684adff79e2704a2792ff46682afb9246fc8 Author: Bart Van Assche <bvanass...@acm.org> AuthorDate: Thu, 14 Feb 2019 15:00:48 -0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 28 Feb 2019 07:55:44 +0100
locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count() This patch does not change any functionality but makes the next patch in this series easier to read. Signed-off-by: Bart Van Assche <bvanass...@acm.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Johannes Berg <johan...@sipsolutions.net> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Waiman Long <long...@redhat.com> Cc: Will Deacon <will.dea...@arm.com> Cc: johannes.b...@intel.com Cc: t...@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-14-bvanass...@acm.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/locking/lockdep.c | 16 +++++++++++++++- kernel/locking/lockdep_internals.h | 3 ++- kernel/locking/lockdep_proc.c | 12 ++++++------ 3 files changed, 23 insertions(+), 8 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 2c6d0b67e7b6..753a9b758266 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2096,7 +2096,7 @@ out_bug: return 0; } -unsigned long nr_lock_chains; +static unsigned long nr_lock_chains; struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS]; int nr_chain_hlocks; static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS]; @@ -2230,6 +2230,20 @@ static int check_no_collision(struct task_struct *curr, return 1; } +/* + * Given an index that is >= -1, return the index of the next lock chain. + * Return -2 if there is no next lock chain. + */ +long lockdep_next_lockchain(long i) +{ + return i + 1 < nr_lock_chains ? i + 1 : -2; +} + +unsigned long lock_chain_count(void) +{ + return nr_lock_chains; +} + /* * Adds a dependency chain into chain hashtable. And must be called with * graph_lock held. diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 2ebb9d0ea91c..d4c197425f68 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -100,7 +100,8 @@ struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i); extern unsigned long nr_lock_classes; extern unsigned long nr_list_entries; -extern unsigned long nr_lock_chains; +long lockdep_next_lockchain(long i); +unsigned long lock_chain_count(void); extern int nr_chain_hlocks; extern unsigned long nr_stack_trace_entries; diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 3d31f9b0059e..9c49ec645d8b 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -104,18 +104,18 @@ static const struct seq_operations lockdep_ops = { #ifdef CONFIG_PROVE_LOCKING static void *lc_start(struct seq_file *m, loff_t *pos) { + if (*pos < 0) + return NULL; + if (*pos == 0) return SEQ_START_TOKEN; - if (*pos - 1 < nr_lock_chains) - return lock_chains + (*pos - 1); - - return NULL; + return lock_chains + (*pos - 1); } static void *lc_next(struct seq_file *m, void *v, loff_t *pos) { - (*pos)++; + *pos = lockdep_next_lockchain(*pos - 1) + 1; return lc_start(m, pos); } @@ -268,7 +268,7 @@ static int lockdep_stats_show(struct seq_file *m, void *v) #ifdef CONFIG_PROVE_LOCKING seq_printf(m, " dependency chains: %11lu [max: %lu]\n", - nr_lock_chains, MAX_LOCKDEP_CHAINS); + lock_chain_count(), MAX_LOCKDEP_CHAINS); seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n", nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS); #endif
