Re: [GIT PULL] Scope-based Resource Management for 6.5

From: Linus Torvalds
Date: Tue Jul 04 2023 - 17:11:44 EST


On Mon, 26 Jun 2023 at 05:57, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> Please consider pulling the SBRM infrastructure so that people can start
> building upon it. Specifically Greg also wants to start using this soon.
>
> Once this lands, I'll start to trickle in the conversions I've done for
> the next release.

So things are quiet (partly presumably due to July 4th in the US) and
I've mostly emptied my merge window queue, so I've pulled this since I
obviously was happy with the final syntax.

However, let's agree to not really use it for 6.5 yet, and consider it
all purely infrastructure for the next release, and for testing it all
out in linux-next etc.

We should probably also strive to avoid it for bug-fixes that end up
going to stable. I'm sure this will all be backported to stable
eventually, but I'd at least personally be happier if that started
happening only after we actually have some more interaction with this.

I hope - and expect - that the core compiler infrastructure should be
stable due to C++ uses of destructors, but I also note that at least
in the system headers I have, the only use of the __cleanup__
attribute seems to be a very special pthread_cleanup_push() helper,
and some (fairly minimal) glib use in the g_auto*() types.

So this attribute has been around forever, and the low-level
functionality has presumably gotten a lot of testing, but at the same
time it really looks like the C interface is somewhat limited in its
use.

I did do a Debian core search on g_autoptr() use, and in the first ten
pages, most uses seemed to be either comments or tests. But there are
certainly *some* real users too.

Anyway, I did find enough use that I'm not worried, but I'd still like
us to take this somewhat slowly.

Let's *not* treat this as a "W00t! Black Friday at Walmart! Everybody
rush in at once!"

Linus