On Sat, Dec 8, 2018 at 10:26 PM Williams, Dan J
<[email protected]> wrote:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
> tags/dax-fixes-4.20-rc6
What's going on with the odd non-exclusive exclusive wait?
prepare_to_wait_exclusive(wq, &ewait.wait, TASK_UNINTERRUPTIBLE);
...
/*
* Entry lock waits are exclusive. Wake up the next waiter since
* we aren't sure we will acquire the entry lock and thus wake
* the next waiter up on unlock.
*/
if (waitqueue_active(wq))
__wake_up(wq, TASK_NORMAL, 1, &ewait.key);
that seems to make little or no sense.
Why isn't that prepare_to_wait_exclusive() just a regular
prepare_to_wait(), and then the whole "let's wake up anybody else" can
be removed?
I've pulled it, but am awaiting explanation of what looks like some
pretty crazy code. I *suspect* it's a copy-and-paste situation where
you took the exclusive wait from somewhere else.
Linus
