linux-kernel - Re: [PATCH 1/2] staging: remove null checks before kfree

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Date:	Thu, 24 Feb 2011 14:25:06 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Ilia Mirkin <imirkin@...m.mit.edu>
Cc:	Greg KH <gregkh@...e.de>, devel@...verdev.osuosl.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] staging: remove null checks before kfree

On Thu, 2011-02-24 at 19:08 +0000, Ilia Mirkin wrote:

> FWIW my reasoning for doing this was that generally the reason you're
> freeing something is because you allocated it, so kfree(NULL) happens
> rarely -- error paths, conditional features, etc. If you actually
> expect the argument to be NULL often, then you would do something like
> if (unlikely(x)) kfree(x). This is done a few times in the core
> kernel. I think it makes more sense for kfree to keep the unlikely
> since in cold paths it won't matter and in hot paths where it is often
> NULL, there should be a conditional at the call site. [I'm sure you'll
> note the lack of an attached benchmark... this is just what makes
> sense to me.]

That unlikely has been there for years, and another year wont hurt
anything ;)

I'll run my unlikely clean up again in December, and we'll see what
needs to be touched then.

Thanks,

-- Steve


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