Messages in this thread | | | Date | Wed, 25 Nov 2015 09:32:14 -0800 | From | "Shi, Yang" <> | Subject | Re: [PATCH] arm64: restore bogomips information in /proc/cpuinfo |
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On 11/25/2015 7:16 AM, Nicolas Pitre wrote: > On Wed, 25 Nov 2015, Jon Masters wrote: > >> On 11/18/15, 1:15 PM, Yang Shi wrote: >> >>> As what Pavel Machek reported [1], some userspace applications depend on >>> bogomips showed by /proc/cpuinfo. >>> >>> Although there is much less legacy impact on aarch64 than arm, but it does >>> break libvirt. >>> >>> Basically, this patch reverts commit >>> 326b16db9f69fd0d279be873c6c00f88c0a4aad5 >>> ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo"), but with >>> some tweak due to context change. >> >> On a total tangent, it would be ideal to (eventually) have something reported >> in /proc/cpuinfo or dmesg during boot that does "accurately" map back to the >> underlying core frequency (as opposed to the generic timer frequency). I have >> seen almost countless silly situations in the industry (external to my own >> organization) in which someone has taken a $VENDOR_X reference system that >> they're not supposed to run benchmarks on, and they've done it anyway. But >> usually on some silicon that's clocked multiples under what production would >> be. Then silly rumors about performance get around because nobody can do >> simple arithmetic and notice that they ought to have at least divided by some >> factor. > > Be my guest my friend. > > According to the common wisdom, the bogomips reporting is completely > senseless at this point and no one should expect anything useful from > it. Therefore I attempted to rehabilitate some meaning into it given > that we just can't get rid of it either and it continues to cause > dammage. You certainly saw where that has led me.
Or we may create a new one, i.e. "cpu MHz" like x86? Then we keep both in cpuinfo so that the userspace could adopt it gradually?
Thanks, Yang
> > > Nicolas >
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