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From: Segher Boessenkool <segher@kernel.crashing.org>
To: "David Laight" <David.Laight@ACULAB.COM>
Cc: paulus@samba.org, Michael Neuling <mikey@neuling.org>,
	sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
	Anton Blanchard <anton@samba.org>
Subject: Re: [PATCH] powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX
Date: Thu, 8 Dec 2011 15:12:26 +0100	[thread overview]
Message-ID: <13A89594-34DE-40C7-8B13-D146C2F7F927@kernel.crashing.org> (raw)
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6D8AF0A@saturn3.aculab.com>

>>> One idea would be to have a structure of function pointers for each
>>> CPU that gets runtime patched into the right places,
>>> similar to how we do some of the MMU fixups.
>>
>> Sounds good to me :-)
>
> Except the indirect jump/call is almost certainly
> never predicted - so will be slow.

What indirect jump?  He said "runtime patched" :-)

Also, that "slow" is largely a myth.


Segher

  reply	other threads:[~2011-12-08 14:11 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-08  5:02 [PATCH] powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX Anton Blanchard
2011-12-08  5:44 ` Kumar Gala
2011-12-08  5:54   ` Michael Neuling
2011-12-08  6:04     ` Anton Blanchard
2011-12-08 13:31       ` Segher Boessenkool
2011-12-08 14:02         ` David Laight
2011-12-08 14:12           ` Segher Boessenkool [this message]
2011-12-08 19:40       ` Benjamin Herrenschmidt
2011-12-08  6:11     ` Anton Blanchard
2011-12-19  3:00       ` Benjamin Herrenschmidt
2011-12-19  3:19         ` Benjamin Herrenschmidt

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