On 23/09/2019 22:27, Peter Zijlstra wrote:

A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

On Mon, Sep 23, 2019 at 07:37:46PM +0300, Pavel Begunkov wrote:

quoted

Just in case duplicating a mail from the cover-letter thread:

Just because every patch should have a self contained and coherent
Changelog.

Well, I will expand the patch description, if we agree on the
implementation (at least conceptually).

quoted

BTW, this monster is mostly a copy-paste from wait_event_*(),
wait_bit_*(). We could try to extract some common parts from these
three, but that's another topic.

I don't think that is another topic at all. It is a quality of
implementation issue. We already have too many copies of all that (3).

For example, ___wait_event() is copied in ___wait_var_event(). Instead
it could accept a wait entry generator or just accept entry from above
and be reused in both cases. I've had such a patch, but want to think
what else could be done.

e.g.

#define generic_wait_event(ENTRY_GEN, ...)
	ENTRY_GEN(wq_entry_name);
	do_wait_event(wq_entry_name);

#define WBQ_ENTRY_GEN(name)
	struct wait_bit_queue_entry tmp = WBQ_INITIALIZER;
	struct wait_queue_entry	name = &tmp->wq_entry;

So basically you want to fudge the wake function to do the/a @cond test,
not unlike what wait_bit already does, but differenly.

Yes

I'm really rather annoyed with C for not having proper lambda functions;
that would make all this so much easier. Anyway, let me have a poke at
this in the morning, it's late already.

Also, is anything actually using wait_queue_entry::private ? I'm
not finding any in a hurry.

-- 
Yours sincerely,
Pavel Begunkov