Currently hlock->read can have the following values: 0: write type 1: read type 2: read recursion type
It would be better to use human readable type than magic numbers. Furthermore, this way it's easier to extend it so that hlock->read has another value. Signed-off-by: Byungchul Park <[email protected]> --- kernel/locking/lockdep.c | 40 ++++++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 16 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 44c8d0d..0ac2f70 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -76,6 +76,14 @@ #define lock_stat 0 #endif +#define LT_WRITE 0 /* 0: write type */ +#define LT_READ_N 1 /* 1: read non-recursion type */ +#define LT_READ_R 2 /* 2: read recursion type */ + +#define is_write(a) ((a) == LT_WRITE) +#define is_read(a) ((a) == LT_READ_N || (a) == LT_READ_R) +#define is_read_r(a) ((a) == LT_READ_R) + /* * lockdep_lock: protects the lockdep graph, the hashes and the * class/list/hash allocators. @@ -271,9 +279,9 @@ static void lock_release_holdtime(struct held_lock *hlock) holdtime = lockstat_clock() - hlock->holdtime_stamp; stats = get_lock_stats(hlock_class(hlock)); - if (hlock->read) + if (is_read(hlock->read)) lock_time_inc(&stats->read_holdtime, holdtime); - else + else if (is_write(hlock->read)) lock_time_inc(&stats->write_holdtime, holdtime); put_lock_stats(stats); } @@ -1828,7 +1836,7 @@ static inline void inc_chains(void) * Allow read-after-read recursion of the same * lock class (i.e. read_lock(lock)+read_lock(lock)): */ - if ((read == 2) && prev->read) + if (is_read_r(read) && is_read(prev->read)) return 2; /* @@ -1906,7 +1914,7 @@ static inline void inc_chains(void) * write-lock never takes any other locks, then the reads are * equivalent to a NOP. */ - if (next->read == 2 || prev->read == 2) + if (is_read_r(next->read) || is_read_r(prev->read)) return 1; /* * Is the <prev> -> <next> dependency already present? @@ -2016,7 +2024,7 @@ static inline void inc_chains(void) * Only non-recursive-read entries get new dependencies * added: */ - if (hlock->read != 2 && hlock->check) { + if (!is_read_r(hlock->read) && hlock->check) { int ret = check_prev_add(curr, hlock, next, distance, &trace, save); if (!ret) @@ -2460,7 +2468,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock, * trylock entries): */ if (ret == 2) - hlock->read = 2; + hlock->read = LT_READ_R; /* * Add dependency only if this lock is not the head * of the chain, and if it's not a secondary read-lock: @@ -2848,7 +2856,7 @@ enum mark_type { hlock = curr->held_locks + i; usage_bit = 2 + (mark << 2); /* ENABLED */ - if (hlock->read) + if (is_read(hlock->read)) usage_bit += 1; /* READ */ BUG_ON(usage_bit >= LOCK_USAGE_STATES); @@ -3060,7 +3068,7 @@ 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 (is_read(hlock->read)) { if (curr->hardirq_context) if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ_READ)) @@ -3079,7 +3087,7 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) } } if (!hlock->hardirqs_off) { - if (hlock->read) { + if (is_read(hlock->read)) { if (!mark_lock(curr, hlock, LOCK_ENABLED_HARDIRQ_READ)) return 0; @@ -3715,7 +3723,7 @@ static int __lock_downgrade(struct lockdep_map *lock, unsigned long ip) curr->curr_chain_key = hlock->prev_chain_key; WARN(hlock->read, "downgrading a read lock"); - hlock->read = 1; + hlock->read = LT_READ_N; hlock->acquire_ip = ip; if (reacquire_held_locks(curr, depth, i)) @@ -4167,7 +4175,7 @@ void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie) if (contending_point < LOCKSTAT_POINTS) stats->contending_point[contending_point]++; if (lock->cpu != smp_processor_id()) - stats->bounces[bounce_contended + !!hlock->read]++; + stats->bounces[bounce_contended + is_read(hlock->read)]++; put_lock_stats(stats); } @@ -4209,13 +4217,13 @@ void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie) stats = get_lock_stats(hlock_class(hlock)); if (waittime) { - if (hlock->read) + if (is_read(hlock->read)) lock_time_inc(&stats->read_waittime, waittime); - else + else if (is_write(hlock->read)) lock_time_inc(&stats->write_waittime, waittime); } if (lock->cpu != cpu) - stats->bounces[bounce_acquired + !!hlock->read]++; + stats->bounces[bounce_acquired + is_read(hlock->read)]++; put_lock_stats(stats); lock->cpu = cpu; @@ -4819,7 +4827,7 @@ static inline struct lock_class *xlock_class(struct cross_lock *xlock) */ static inline int depend_before(struct held_lock *hlock) { - return hlock->read != 2 && hlock->check && !hlock->trylock; + return !is_read_r(hlock->read) && hlock->check && !hlock->trylock; } /* @@ -4827,7 +4835,7 @@ static inline int depend_before(struct held_lock *hlock) */ static inline int depend_after(struct held_lock *hlock) { - return hlock->read != 2 && hlock->check; + return !is_read_r(hlock->read) && hlock->check; } /* -- 1.9.1
