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From: "Kevin D. Kissell" <kevink@mips.com>
To: "Ralf Baechle" <ralf@uni-koblenz.de>,
	"Carsten Langgaard" <carstenl@mips.com>
Cc: <linux-mips@linux-mips.org>
Subject: Re: Prefetches in memcpy
Date: Tue, 5 Nov 2002 17:13:48 +0100	[thread overview]
Message-ID: <00fb01c284e6$5b7bf4f0$10eca8c0@grendel> (raw)
In-Reply-To: 20021105163806.A24996@bacchus.dhis.org

From: "Ralf Baechle" <ralf@uni-koblenz.de>
> So I think the fix will have to be:
> 
>  - Avoid prefetching beyond the end of the copy area in memcpy and memmove.
>  - Introduce a second variant of memcpy that never does prefetching.  This
>    one will be safe to use in KSEG1 / uncached XKPHYS also and will be used
>    for memcpy_fromio, memcpy_toio and friends.

Assuming we had a version that prefetched exactly to the end
of the source memory block and no further, why would we need
the second variant?

            Kevin K.

WARNING: multiple messages have this Message-ID (diff)
From: "Kevin D. Kissell" <kevink@mips.com>
To: Ralf Baechle <ralf@uni-koblenz.de>,
	Carsten Langgaard <carstenl@mips.com>
Cc: linux-mips@linux-mips.org
Subject: Re: Prefetches in memcpy
Date: Tue, 5 Nov 2002 17:13:48 +0100	[thread overview]
Message-ID: <00fb01c284e6$5b7bf4f0$10eca8c0@grendel> (raw)
Message-ID: <20021105161348.haq7BWCCeHX17NQcrqo938bLjXuTrOWYiirA8yncF8g@z> (raw)
In-Reply-To: 20021105163806.A24996@bacchus.dhis.org

From: "Ralf Baechle" <ralf@uni-koblenz.de>
> So I think the fix will have to be:
> 
>  - Avoid prefetching beyond the end of the copy area in memcpy and memmove.
>  - Introduce a second variant of memcpy that never does prefetching.  This
>    one will be safe to use in KSEG1 / uncached XKPHYS also and will be used
>    for memcpy_fromio, memcpy_toio and friends.

Assuming we had a version that prefetched exactly to the end
of the source memory block and no further, why would we need
the second variant?

            Kevin K.

  reply	other threads:[~2002-11-05 16:10 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-11-05 13:45 Prefetches in memcpy Carsten Langgaard
2002-11-05 15:38 ` Ralf Baechle
2002-11-05 16:13   ` Kevin D. Kissell [this message]
2002-11-05 16:13     ` Kevin D. Kissell
2002-11-05 16:29     ` Ralf Baechle
2002-11-05 16:41     ` Ralf Baechle
2002-11-05 17:26     ` Alan Cox
2002-12-04 15:06   ` Carsten Langgaard
2002-12-05  9:32     ` Dominic Sweetman
2002-12-05 15:14       ` Carsten Langgaard
2002-12-05 15:47         ` Maciej W. Rozycki
2002-12-08  7:06     ` Gilad
2002-12-08 10:01       ` Kevin D. Kissell
2002-12-08 10:01         ` Kevin D. Kissell

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