From:	 Ingo Molnar <mingo@elte.hu>
To:	 Roy Sigurd Karlsbakk <roy@karlsbakk.net>
Subject: Re: speed difference between using hard-linked and modular drives?
Date:	 Thu, 8 Nov 2001 18:37:57 +0100 (CET)
Cc:	 <linux-kernel@vger.kernel.org>


On Thu, 8 Nov 2001, Ingo Molnar wrote:

> > Are there any speed difference between hard-linked device drivers and
> > their modular counterparts?
>
> minimal. a few instructions per IO.

Arjan pointed out that there is also the cost of TLB misses due to
vmalloc()-ing module libraries, which can be as high as a 5% slowdown.

we should fix this by trying to allocate continuous physical memory if
possible, and fall back to vmalloc() only if this allocation fails.

	Ingo

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