Re: [GIT PULL] vfs pidfd

From: Linus Torvalds <torvalds@linux-foundation.org>
To: Christian Brauner <brauner@kernel.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [GIT PULL] vfs pidfd
Date: Mon, 11 Mar 2024 13:05:06 -0700	[thread overview]
Message-ID: <CAHk-=wigcyOxVQuQrmk2Rgn_-B=1+oQhCnTTjynQs0CdYekEYg@mail.gmail.com> (raw)
In-Reply-To: <20240308-vfs-pidfd-b106369f5406@brauner>

On Fri, 8 Mar 2024 at 02:14, Christian Brauner <brauner@kernel.org> wrote:
>
> * Move pidfds from the anonymous inode infrastructure to a tiny
>   pseudo filesystem. This will unblock further work that we weren't able
>   to do simply because of the very justified limitations of anonymous
>   inodes. Moving pidfds to a tiny pseudo filesystem allows for statx on
>   pidfds to become useful for the first time. They can now be compared
>   by inode number which are unique for the system lifetime.

So I obviously pulled this already, but I did have one question - we
don't make nsfs conditional, and I'm not convinced we should make
pidfs conditional either.

I think (and *hope*) all the semantic annoyances got sorted out, and I
don't think there are any realistic size advantages to not enabling
CONFIG_FS_PID.

Is there some fundamental reason for that config entry to exist?

            Linus