From: "H. Peter Anvin" <hpa@zytor.com>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Agner Fog <agner@agner.org>, linux-kernel@vger.kernel.org
Subject: Re: ABI change for device drivers using future AVX instruction set
Date: Wed, 25 Jun 2008 18:11:07 -0700 [thread overview]
Message-ID: <4862ECAB.1040402@zytor.com> (raw)
In-Reply-To: <20080625092224.736c2541@infradead.org>
Arjan van de Ven wrote:
>
> Let me repeat this loud and clear:
>
> It is not allowed to use floating point, SSE of AVX in device drivers.
>
> (there are few places that very carefully do this anyway, the raid5
> code being the most obvious one, but we should not add more)
>
Sadly, AVX repeats the mistakes of SSE1, and doesn't implement proper
wide support for integer operations. It has the basic bitwide stuff,
which makes it usable for RAID-5, but it doesn't extend MMX (which SSE2
eventually got around to), so it's not usable for RAID-6. I'd hoped to
find a VPERM-style instruction, like SSE5 has :(
-hpa
next prev parent reply other threads:[~2008-06-26 1:14 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-25 15:32 ABI change for device drivers using future AVX instruction set Agner Fog
2008-06-25 16:22 ` Arjan van de Ven
2008-06-25 19:54 ` Agner Fog
2008-06-25 20:09 ` Arjan van de Ven
2008-06-26 1:11 ` H. Peter Anvin [this message]
2008-06-27 11:31 ` Agner Fog
2008-06-27 14:22 ` Arjan van de Ven
2008-06-28 8:05 ` Agner Fog
2008-06-28 8:10 ` David Miller
2008-06-28 11:47 ` Andi Kleen
2008-06-28 15:09 ` Agner Fog
2008-06-28 15:44 ` Helge Hafting
2008-06-28 20:02 ` Andi Kleen
2008-06-29 11:33 ` Avi Kivity
2008-06-29 12:21 ` Andi Kleen
2008-06-29 12:31 ` Avi Kivity
2008-06-29 13:07 ` Andi Kleen
2008-06-29 13:18 ` Avi Kivity
2008-06-29 13:23 ` Andi Kleen
2008-06-29 13:29 ` Avi Kivity
2008-06-29 22:08 ` H. Peter Anvin
2008-06-29 12:29 ` Alan Cox
2008-07-01 15:30 ` Arjan van de Ven
2008-06-25 20:14 ` Alan Cox
2008-06-26 14:01 ` Andi Kleen
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