Re: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata

From: Pavel Machek
Date: Thu Sep 18 2003 - 02:44:44 EST


Hi!

> I think Alan brought up a very good point. Even if you
> use a generic kernel that avoids prefetch use on Athlon
> (which I am opposed to), it doesn't solve the problem
> of user space programs detecting that the ISA supports
> prefetch and using prefetch instructions and hitting the
> errata on Athlon.
>
> The user space problem worries me more, because the expectation
> is that if CPUID says the program can use perfetch, it could
> and should regardless of what the kernel decided to do here.

User programs should not rely on cpuid; they should read /proc/cpuinfo
exactly because this kind of errata.

Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
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