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

From: Will Deacon
Date: Wed Oct 08 2014 - 09:38:27 EST


On Wed, Oct 08, 2014 at 02:31:47PM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> On Wed, Oct 08, 2014 at 10:17:41AM +0100, Will Deacon wrote:
> > 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?
>
> Yes, it's in 3.16.4, did I do something wrong by accepting it?

Nah, it's a trivial patch that I struggle to get excited about. I'm just not
sure why it's being sent again, after you already accepted it.

Will
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