[8u] RFR for JDK-8154324: Request to backport JDK-6515172 to 8u

[Shafi Ahmad]

May I get second review for this.

Updated webrev: http://cr.openjdk.java.net/~shshahma/8154324/webrev.02/

Regards,
Shafi

> -----Original Message-----
> From: David Holmes
> Sent: Wednesday, September 14, 2016 3:21 AM
> To: Shafi Ahmad; hotspot-dev at openjdk.java.net
> Subject: Re: [8u] RFR for JDK-8154324: Request to backport JDK-6515172 to
> 8u
> 
> Hi Shafi,
> 
> On 12/09/2016 11:20 PM, Shafi Ahmad wrote:
> > Hi,
> >
> > Please find updated webrev:
> > http://cr.openjdk.java.net/~shshahma/8154324/webrev.01/
> > I have incorporated both review comment by David.
> >   1. Removed unrelated comment.
> >   2. Removed unreferenced code ' diagnostic(bool, UseCpuAllocPath, false,'
> 
> Incorrect comment here in globals_linux.hpp:
> 
> !   diagnostic(bool, PrintActiveCpus, false,                              \
> !              "Use CPU_ALLOC code path in os::active_processor_count ")
> 
> should be:
> 
> "Print the number of CPUs detected in os::active_processor_count"
> 
> ---
> 
> os_linux.cpp:
> 
> if(PrintActiveCpus) {
> 
> Need space after if.
> 
> --
> 
> Otherwise okay. No need to see updated webrev if above are fixed.
> 
> Thanks,
> David
> 
> >
> > Regards,
> > Shafi
> >
> >> -----Original Message-----
> >> From: David Holmes
> >> Sent: Friday, September 09, 2016 11:29 AM
> >> To: Shafi Ahmad; hotspot-dev at openjdk.java.net
> >> Subject: Re: [8u] RFR for JDK-8154324: Request to backport
> >> JDK-6515172 to 8u
> >>
> >> Hi Shafi,
> >>
> >> On 9/09/2016 3:46 PM, Shafi Ahmad wrote:
> >>> Hi,
> >>>
> >>> Please review the backport [modified] of bug: "JDK-6515172
> >> Runtime.availableProcessors() ignores Linux taskset command" to jdk8u.
> >>>
> >>> Please note that the backport is not clean and we can't do as it is.
> >>> Please
> >> note
> >>>   1. The changes are made by 'Andreas Eriksson' who left Oracle.
> >>>   2. There is difference in logging mechanism in jdk9 and jdk8 is
> >>> different
> >> and file logTag.hpp doesn't exists in jdk8.
> >>>   3. Newly added test pass after this change. It fails without this change.
> >>>
> >>> Webrev link:
> http://cr.openjdk.java.net/~shshahma/8154324/webrev.00/
> >>> Jdk9 bug: https://bugs.openjdk.java.net/browse/JDK-6515172
> >>> Jdk8 bug: https://bugs.openjdk.java.net/browse/JDK-8154324
> >>> Original patch pushed to jdk9:
> >>> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/c5480d4abfe4
> >>
> >> I worked extensively with Andreas on this as there were a number of
> issues.
> >> I'll have to try and find those discussions to see where we ended up.
> >>
> >> The backport as stands is not quite appropriate. For example it adds:
> >>
> >> diagnostic(bool, UseCpuAllocPath, false,
> >>
> >> but that does not exist in the actual code for 8.
> >>
> >> Also this comment:
> >>
> >> + // If it appears there may be more than 1024 processors then we do
> >> + a // dynamic check - see 6515172 for details.
> >>
> >> is wrong as there is no dynamic check in this version of the code.
> >>
> >> The last I recall with this is that there were issues caused by
> >> building with one version of glibc and running (or trying to) on
> >> later versions of glibc. But as I said I will have to see if I have the discussion
> from that effort.
> >>
> >> David
> >> ----
> >>
> >>> Testing: jprt and running jtreg.
> >>>
> >>> Regards,
> >>> Shafi
> >>>