Re: [PATCH 2/7] sched: change wake_up_bit() and related function to expect unsigned long *
From: NeilBrown
Date: Mon Sep 16 2024 - 16:38:00 EST
On Tue, 17 Sep 2024, Peter Zijlstra wrote:
> On Mon, Sep 16, 2024 at 09:48:11PM +1000, NeilBrown wrote:
> > On Mon, 16 Sep 2024, Peter Zijlstra wrote:
> > > On Mon, Aug 26, 2024 at 04:30:59PM +1000, NeilBrown wrote:
> > > > wake_up_bit() currently allows a "void *". While this isn't strictly a
> > > > problem as the address is never dereferenced, it is inconsistent with
> > > > the corresponding wait_var_event() which requires "unsigned long *" and
> > > > does dereference the pointer.
> > >
> > > I'm having trouble parsing this. The way I read it, you're contradicting
> > > yourself. Where does wait_var_event() require 'unsigned long *' ?
> >
> > Sorry, that is meant so as "the corresponding wait_on_bit()".
> >
> >
> > >
> > > > And code that needs to wait for a change in something other than an
> > > > unsigned long would be better served by wake_up_var().
> > >
> > > This, afaict the whole var thing is size invariant. It only cares about
> > > the address.
> > >
> >
> > Again - wake_up_bit(). Sorry - bits are vars were swimming around my
> > brain and I didn't proof-read properly.
> >
> > This patch is all "bit", no "var".
>
> OK :-)
>
> Anyway, other than that the patches look fine, but given we're somewhat
> in the middle of the merge window and all traveling to get into Vienna
> and have a few beers, I would much prefer merging these patches after
> -rc1, that okay?
>
Yes, that's OK. Thanks for having a look. Have fun in Vienna.
NeilBrown