On Mon, Aug 06, 2018 at 03:27:05PM -0700, Andrew Morton wrote: > On Mon, 6 Aug 2018 10:30:58 +0200 Christoph Hellwig <hch@xxxxxx> wrote: > > > If we get a keyed wakeup for a aio poll waitqueue and wake can acquire the > > ctx_lock without spinning we can just complete the iocb straight from the > > wakeup callback to avoid a context switch. > > Why do we try to avoid spinning on the lock? Because we are called with the lock on the waitqueue called, which nests inside it. > > + /* try to complete the iocb inline if we can: */ > > ie, this comment explains 'what" but not "why". > > (There's a typo in Subject:, btw) Because it is faster obviously. I can update the comment.
