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Date: Tue, 14 Aug 2018 08:38:49 -0700
Subject: Re: svn commit: r337754 - head/sys/x86/x86
From: Ravi Pokala <rpokala@freebsd.org>
To: Andriy Gapon <avg@FreeBSD.org>, Mark Johnston <markj@freebsd.org>,
 <src-committers@freebsd.org>, <svn-src-all@freebsd.org>,
 <svn-src-head@freebsd.org>
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Thread-Topic: svn commit: r337754 - head/sys/x86/x86
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 <afb7b9a8-19d8-e763-e3ed-c12e2f7094d6@FreeBSD.org>
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-----Original Message-----
From: <owner-src-committers@freebsd.org> on behalf of Andriy Gapon <avg@FreeBSD.org>
Date: 2018-08-14, Tuesday at 08:34
To: Mark Johnston <markj@freebsd.org>, <src-committers@freebsd.org>, <svn-src-all@freebsd.org>, <svn-src-head@freebsd.org>
Subject: Re: svn commit: r337754 - head/sys/x86/x86

> On 14/08/2018 17:02, Mark Johnston wrote:
>>   At some point memcpy() may be an ifunc, ifunc resolution cannot be done
>>   until CPU identification has been performed, and CPU identification must
>>   be done after loading any microcode updates.
> 
> Wouldn't it be cool if before an ifunc is resolved (to a proper
> optimized version) it pointed to a default implementation that is
> sufficiently naive and robust that it can work on all CPUs?
> But I don't know much about ifunc implementation, so no idea if it can
> work like that.

Or, if that can't be done, have a pre_ifunc_memcpy() with the default implementation, which is explicitly for use before ifuncs are set up.

-Ravi

> -- 
> Andriy Gapon