linux-kernel - Re: [PATCH v7 01/16] hashtable: introduce a small and naive hashtable

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Message-ID: <20121029161809.GA4066@htj.dyndns.org>
Date:	Mon, 29 Oct 2012 09:18:09 -0700
From:	Tejun Heo <tj@...nel.org>
To:	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
Cc:	Sasha Levin <levinsasha928@...il.com>,
	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
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Subject: Re: [PATCH v7 01/16] hashtable: introduce a small and naive hashtable

Hello,

On Mon, Oct 29, 2012 at 12:14:12PM -0400, Mathieu Desnoyers wrote:
> Most of the calls to this initialization function apply it on zeroed
> memory (static/kzalloc'd...), which makes it useless. I'd actually be in
> favor of removing those redundant calls (as I pointed out in another
> email), and document that zeroed memory don't need to be explicitly
> initialized.
> 
> Those sites that need to really reinitialize memory, or initialize it
> (if located on the stack or in non-zeroed dynamically allocated memory)
> could use a memset to 0, which will likely be faster than setting to
> NULL on many architectures.

I don't think it's a good idea to optimize out the basic encapsulation
there.  We're talking about re-zeroing some static memory areas which
are pretty small.  It's just not worth optimizing out at the cost of
proper initializtion.  e.g. We might add debug fields to list_head
later.

Thanks.

-- 
tejun
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