• Ingo Molnar's avatar
    sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming · 2055da97
    Ingo Molnar authored
    So I've noticed a number of instances where it was not obvious from the
    code whether ->task_list was for a wait-queue head or a wait-queue entry.
    
    Furthermore, there's a number of wait-queue users where the lists are
    not for 'tasks' but other entities (poll tables, etc.), in which case
    the 'task_list' name is actively confusing.
    
    To clear this all up, name the wait-queue head and entry list structure
    fields unambiguously:
    
    	struct wait_queue_head::task_list	=> ::head
    	struct wait_queue_entry::task_list	=> ::entry
    
    For example, this code:
    
    	rqw->wait.task_list.next != &wait->task_list
    
    ... is was pretty unclear (to me) what it's doing, while now it's written this way:
    
    	rqw->wait.head.next != &wait->entry
    
    ... which makes it pretty clear that we are iterating a list until we see the head.
    
    Other examples are:
    
    	list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
    	list_for_each_entry(wq, &fence->wait.task_list, task_list) {
    
    ... where it's unclear (to me) what we are iterating, and during review it's
    hard to tell whether it's trying to walk a wait-queue entry (which would be
    a bug), while now it's written as:
    
    	list_for_each_entry_safe(pos, next, &x->head, entry) {
    	list_for_each_entry(wq, &fence->wait.head, entry) {
    
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: 's avatarIngo Molnar <mingo@kernel.org>
    2055da97