Re: [PATCH v2 0/3] arm64: perf_event: Fix time offset prior to epoch

[Peter Zijlstra]

On Tue, May 12, 2020 at 02:38:12PM +0800, Leo Yan wrote:

> I have verified this change, it works as expected on my Arm64 board.
> Also paste the updated code which makes building success with minor
> fixing.

W00t !

> I am not sure how to proceed, will you merge this?  Or you want me to
> send out formal patches (or only for the Arm64 part)?

I suppose I can write a Changelog for the thing, Will asked for another
change as well.

> P.s. it's shame I still missed you guys suggestion in prvious thread
> even though you have provide enough ifno, and thank you for the helping!

All good.


> ---8<---

> -	/*
> -	 * time_shift is not expected to be greater than 31 due to
> -	 * the original published conversion algorithm shifting a
> -	 * 32-bit value (now specifies a 64-bit value) - refer
> -	 * perf_event_mmap_page documentation in perf_event.h.
> -	 */
> -	if (shift == 32) {
> -		shift = 31;
> -		userpg->time_mult >>= 1;
> -	}

Is there a reason you completely lost that? IIRC I preserved that.
Although I don't know if it is still relevant.

I'll keep it for now, and removal can be a separate patch with proper
justification, ok?