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memcpy and prefetch

To: linux-mips@linux-mips.org, "VomLehn, David" <dvomlehn@cisco.com>, msundius@sundius.com
Subject: memcpy and prefetch
From: Michael Sundius <msundius@cisco.com>
Date: Tue, 27 Jan 2009 15:00:36 -0800
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I know this topic has been written about but so excuse me if I am redundant. I saw lots of talk in the archives but I don't know if a solution was ever arrived
at. so:

what is the current state of the use of prefetch in memcpy()? it seems that
it is #undef-ed if CONFIG_DMA_COHERENT is not turned on.

is this still because the memcpy does not check to prevent a prefetch of
addresses beyond the end of the buffer?

If so, what was the reason a solution was abandoned....

also  has anyone out there written a memcopy that does use prefetch
intelligently (for mips32 that is)?


thanks
Mike



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