futex_top_waiter() returns the top-waiter on the pi_mutex. Assinging this to a variable 'match' totally obscures the code. Signed-off-by: Peter Zijlstra (Intel) --- kernel/futex.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1120,14 +1120,14 @@ static int attach_to_pi_owner(u32 uval, static int lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, union futex_key *key, struct futex_pi_state **ps) { - struct futex_q *match = futex_top_waiter(hb, key); + struct futex_q *top_waiter = futex_top_waiter(hb, key); /* * If there is a waiter on that futex, validate it and * attach to the pi_state when the validation succeeds. */ - if (match) - return attach_to_pi_state(uval, match->pi_state, ps); + if (top_waiter) + return attach_to_pi_state(uval, top_waiter->pi_state, ps); /* * We are the first waiter - try to look up the owner based on @@ -1174,7 +1174,7 @@ static int futex_lock_pi_atomic(u32 __us struct task_struct *task, int set_waiters) { u32 uval, newval, vpid = task_pid_vnr(task); - struct futex_q *match; + struct futex_q *top_waiter; int ret; /* @@ -1200,9 +1200,9 @@ static int futex_lock_pi_atomic(u32 __us * Lookup existing state first. If it exists, try to attach to * its pi_state. */ - match = futex_top_waiter(hb, key); - if (match) - return attach_to_pi_state(uval, match->pi_state, ps); + top_waiter = futex_top_waiter(hb, key); + if (top_waiter) + return attach_to_pi_state(uval, top_waiter->pi_state, ps); /* * No waiter and user TID is 0. We are here because the @@ -1292,11 +1292,11 @@ static void mark_wake_futex(struct wake_ q->lock_ptr = NULL; } -static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this, +static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *top_waiter, struct futex_hash_bucket *hb) { struct task_struct *new_owner; - struct futex_pi_state *pi_state = this->pi_state; + struct futex_pi_state *pi_state = top_waiter->pi_state; u32 uninitialized_var(curval), newval; DEFINE_WAKE_Q(wake_q); bool deboost; @@ -1317,11 +1317,11 @@ static int wake_futex_pi(u32 __user *uad /* * It is possible that the next waiter (the one that brought - * this owner to the kernel) timed out and is no longer + * top_waiter owner to the kernel) timed out and is no longer * waiting on the lock. */ if (!new_owner) - new_owner = this->task; + new_owner = top_waiter->task; /* * We pass it to the next owner. The WAITERS bit is always @@ -2631,7 +2631,7 @@ static int futex_unlock_pi(u32 __user *u u32 uninitialized_var(curval), uval, vpid = task_pid_vnr(current); union futex_key key = FUTEX_KEY_INIT; struct futex_hash_bucket *hb; - struct futex_q *match; + struct futex_q *top_waiter; int ret; retry: @@ -2655,9 +2655,9 @@ static int futex_unlock_pi(u32 __user *u * all and we at least want to know if user space fiddled * with the futex value instead of blindly unlocking. */ - match = futex_top_waiter(hb, &key); - if (match) { - ret = wake_futex_pi(uaddr, uval, match, hb); + top_waiter = futex_top_waiter(hb, &key); + if (top_waiter) { + ret = wake_futex_pi(uaddr, uval, top_waiter, hb); /* * In case of success wake_futex_pi dropped the hash * bucket lock.