RFR(S): 8231457 Asserts on AIX because os::elapsed_counter() is not monotonic

[Zeller, Arno]

Hi David,

the tests look good and the changeset is unchanged (webrev: http://cr.openjdk.java.net/~azeller/webrevs/8231457_2/).
Feel free to push any time you like. 

Thanks a lot for your support,
Arno


On 26/09/2019 15:53 David Holmes wrote:
> Hi Arno,
> 
> On 26/09/2019 11:11 pm, Zeller, Arno wrote:
> > Hi David,
> >
> > thanks for reviewing and sponsoring. I just put the patch in our nightly test
> and would prefer to wait till tomorrow for the results - but I expect no issues.
> 
> No problem, just let me know when you're ready and point me to the final
> changeset. It's after 11pm for me now anyway :)
> 
> Cheers,
> David
> 
> > Best regards,
> > Arno
> >
> >> -----Original Message-----
> >> From: David Holmes <david.holmes at oracle.com>
> >> Sent: Donnerstag, 26. September 2019 13:34
> >> To: Zeller, Arno <arno.zeller at sap.com>; hotspot-runtime-
> >> dev at openjdk.java.net
> >> Subject: Re: RFR(S): 8231457 Asserts on AIX because
> os::elapsed_counter() is
> >> not monotonic
> >>
> >> Hi Arno,
> >>
> >> On 26/09/2019 8:37 pm, Zeller, Arno wrote:
> >>> Hi,
> >>>
> >>> we have seen assertions on AIX 7.2 on Power9 that complain about
> >> negative durations. The issue seems to be caused by the implementation
> of
> >> o::elapsed_counter() on AIX that uses gettimeofday which is not
> monotonic.
> >> To solve the issue I prepared a small patch that let os::elapsed_counter()
> use
> >> javaTimeNanos() which should be monotonic. I had to adjust also
> >> os::elapsed_frequency() and os::elapsedTime() to be consistent.
> >>>
> >>> Bug: https://bugs.openjdk.java.net/browse/JDK-8231457
> >>> Webrev: http://cr.openjdk.java.net/~azeller/webrevs/8231457_2/
> >>>
> >>> I will need a sponsor for this patch.
> >>
> >> Changes looks good. I will sponsor this for you. Will wait for a second
> >> reviewer.
> >>
> >> Thanks,
> >> David
> >>
> >>
> >>> Best regards,
> >>> Arno
> >>>