From: Linus Torvalds <torvalds@linux-foundation.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Bart Van Assche <bvanassche@acm.org>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
ksummit@lists.linux.dev, Dan Williams <dan.j.williams@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Dan Carpenter <dan.carpenter@linaro.org>
Subject: Re: Clarifying confusion of our variable placement rules caused by cleanup.h
Date: Tue, 18 Nov 2025 11:22:27 -0800 [thread overview]
Message-ID: <CAHk-=whPZoi03ZwphxiW6cuWPtC3nyKYS8_BThgztCdgPWP1WA@mail.gmail.com> (raw)
In-Reply-To: <20251118141720.11c8d4d6@gandalf.local.home>
On Tue, 18 Nov 2025 at 11:16, Steven Rostedt <rostedt@goodmis.org> wrote:
>
> I've been doing the above, and was even going to recommend it to James. But
> if it is preferred to declare the __free() variables where they are
> allocated, I'd be much happier.
I'm not going to make some hard rule that "it's preferred", but I
think it's simpler and clearer, and I would not want to discourage it.
That said, I *do* want to discourage the rash of mindless conversions.
I do think th is is a situation where people should pick the more
readable version when writing code, *not* a "let's convert existing
code that isn't being otherwise modified" situation.
And your example of
> struct foo *var __free(kfree) = NULL;
>
> if (ret < 0)
> return -ERROR;
>
> [ several more error exits ]
>
> var = kmalloc(..);
is exactly where I do think that just moving the declaration down does
actually make code sufficiently better that it then outweighs the "now
you have the variable declarations in random places".
Because I really feel like the whole "__free(kfree) = NULL" thing
doesn't make sense on its own. It really only makes sense when paired
with the "kmalloc()". And _that_ is why they go together.
But again: I don't want to make this some kind of hard rule, and I
think it should be done judiciously and with taste, not some kind of
crazy conversion thing.
Linus
next prev parent reply other threads:[~2025-11-18 19:22 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-18 16:39 James Bottomley
2025-11-18 17:18 ` Bart Van Assche
2025-11-18 18:38 ` Linus Torvalds
2025-11-18 19:04 ` Bart Van Assche
2025-11-18 19:14 ` Linus Torvalds
2025-11-18 20:43 ` Al Viro
2025-11-18 19:15 ` H. Peter Anvin
2025-11-18 19:11 ` H. Peter Anvin
2025-11-18 19:16 ` Linus Torvalds
2025-11-18 19:19 ` H. Peter Anvin
2025-11-18 19:17 ` Steven Rostedt
2025-11-18 19:22 ` Linus Torvalds [this message]
2025-11-18 19:56 ` Steven Rostedt
2025-11-18 20:23 ` Linus Torvalds
2025-11-18 21:05 ` Linus Torvalds
2025-11-18 20:21 ` James Bottomley
2025-11-18 20:30 ` Linus Torvalds
2025-11-18 20:51 ` Steven Rostedt
2025-11-18 21:10 ` James Bottomley
2025-11-18 22:34 ` Steven Rostedt
2025-11-18 23:32 ` James Bottomley
2025-11-18 19:23 ` H. Peter Anvin
2025-11-18 20:28 ` James Bottomley
2025-11-25 13:09 ` Jani Nikula
2025-11-25 14:25 ` Alexey Dobriyan
2025-11-25 15:32 ` Stephen Hemminger
2025-11-25 16:04 ` Steven Rostedt
2025-11-25 17:57 ` H. Peter Anvin
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