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Date: Fri, 10 May 2024 08:33:54 +0200
From: Christian Brauner <brauner@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Daniel Vetter <daniel@ffwll.ch>, Simon Ser <contact@emersion.fr>, 
	Pekka Paalanen <pekka.paalanen@collabora.com>, 
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Subject: Re: [Linaro-mm-sig] Re: [PATCH] epoll: try to be a _bit_ better
 about file lifetimes
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On Thu, May 09, 2024 at 08:48:20AM -0700, Linus Torvalds wrote:
> On Thu, 9 May 2024 at 04:39, Christian Brauner <brauner@kernel.org> wrote:
> >
> > Not worth it without someone explaining in detail why imho. First pass
> > should be to try and replace kcmp() in scenarios where it's obviously
> > not needed or overkill.
> 
> Ack.
> 
> > I've added a CLASS(fd_raw) in a preliminary patch since we'll need that
> > anyway which means that your comparison patch becomes even simpler imho.
> > I've also added a selftest patch:
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git/log/?h=vfs.misc
> 
> LGTM.
> 
> Maybe worth adding an explicit test for "open same file, but two
> separate opens, F_DUPFD_QUERY returns 0? Just to clarify the "it's not
> testing the file on the filesystem for equality, but the file pointer
> itself".

Yep, good point. Added now.