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

[Zeller, Arno]

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.

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
> >