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

[Shafi Ahmad]

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,'

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
> >