Messages in this thread | | | Date | Thu, 18 Sep 2003 15:05:09 +0100 | From | Dave Jones <> | Subject | Re: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata |
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On Thu, Sep 18, 2003 at 09:43:31AM +0200, Pavel Machek wrote:
> > 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;
Depends. /dev/cpu/x/cpuid is preferred over cpuinfo, as it remains constant across kernel versions.
> they should read /proc/cpuinfo exactly because this kind of errata.
We don't do any change to /proc/cpuinfo in this case. As I mentioned in an earlier mail, the only way you could disable prefetch in this way would be by reporting the entire sse/3dnow instruction sets as unavailable which is overkill.
With Andi's fix, userspace programs doing prefetch get fixed up transparently, making this a non-issue.
Dave
-- Dave Jones http://www.codemonkey.org.uk - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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