Re: [PATCH] arm: armv7: perf: fix armv7 ref-cycles error

From: Will Deacon
Date: Wed Oct 08 2014 - 05:18:08 EST

On Wed, Oct 08, 2014 at 04:06:12AM +0100, zhangzhiqiang wrote:
> hi all,
> ----------------------------------------
> ref-cycles event is specially to Intel core, but can still used in arm architecture
> with the wrong return value with 3.10 stable. for instance:
> perf stat -e ref-cycles sleep 1
> Performance counter stats for 'sleep 1':
> 0 ref-cycles
> 1.002381916 seconds time elapsed
> this patch fix the bug and make it return NOT SUPPORTED
> distinctly.
> In upstream this bug has been fixed by other way(not primary for the bug), which changes more than one file
> and more than 1000 lines. the primary commit is 6b7658ec8a100b608e59e3cde353434db51f5be0.
> besides we can not simply cherry-pick.

I thought I saw Greg pick this up the other day?

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