Re: [PATCH] Export current_is_keventd() for libphy

Andrew Morton
2006-12-07T18:17:40Z

On Thu, 7 Dec 2006 10:01:56 -0800 (PST)
Linus Torvalds <torvalds@osdl.org> wrote:

>
>
> On Thu, 7 Dec 2006, Andrew Morton wrote:
> >
> > umm.. Putting a work_struct* into struct cpu_workqueue_struct and then
> > doing appropriate things with cpu_workqueue_struct.lock might work.
>
> Yeah, that looks sane. We can't hide anything in "struct work", because we
> can't trust it any more once it's been dispatched,

We _can_ trust it in the context of

void flush_work(struct work_struct *work)

because the caller "owns" the work_struct. It'd be pretty nutty for the
caller to pass in a pointer to something which could be freed at any time.
Most flush_work_queue() callers do something like:

flush_scheduled_work();
kfree(my_object_which_contains_a_work_struct);

hopefully libphy follows that model...

> but adding a pointer to
> the cpu_workqueue_struct that is only used to compare against another
> pointer sounds fine.

ho-hum. I'll take a look at turning that into something which compiles,
then I'll convert a few oft-used flush_scheduled_work() callers over to use
it. To do this on a sensible timescale perhaps means that we should export
current_is_keventd(), get the howling hordes off our backs.