RFR (XS) 8061467: Add UseLargePages to TestNUMAPageSize

[Per Liden]

Hi,

On 08/13/2018 06:22 PM, JC Beyler wrote:
> Hi all,
> 
> I added Per's fix into the webrev:
> http://cr.openjdk.java.net/~jcbeyler/8063110/webrev.02/
> 
> (I also put you Thomas as reviewer, I was not sure Per wanted to be put 
> as reviewer, let me know).

Sure, you can put me as reviewer.

/Per

> 
> Not sure if you wanted to wait or not to push it but at least this 
> version would be the version that does not run with ZGC.
> 
> Thanks for your help,
> Jc
> 
> On Mon, Aug 13, 2018 at 5:54 AM Per Liden <per.liden at oracle.com 
> <mailto:per.liden at oracle.com>> wrote:
> 
>     On 08/13/2018 11:41 AM, Thomas Schatzl wrote:
>      > Hi,
>      >
>      >    while testing this patch before push it seems like the problem
>     is ZGC
>      > which does not fall back to using small pages (which I did not know).
>      >
>      >> [5.048s][error][gc,init] Not enough space available on the backing
>      > filesystem to hold the current max
>      >> [5.048s][error][gc,init] Java heap size (128M). Forcefully lowering
>      > max Java heap size to 0M (0%).
>      >> Error occurred during initialization of VM
>      >> java.lang.OutOfMemoryError: Java heap too small
>      >
>      > I will hold off pushing this before this issue has been resolved
>     in one
>      > way or the other.
> 
>     UseNUMA is enabled by default in ZGC, so it's tested frequently anyway.
>     I guess the easiest solution is to just not run this test when ZGC is
>     enabled, something like this:
> 
>     diff --git a/test/hotspot/jtreg/gc/TestNUMAPageSize.java
>     b/test/hotspot/jtreg/gc/TestNUMAPageSize.java
>     --- a/test/hotspot/jtreg/gc/TestNUMAPageSize.java
>     +++ b/test/hotspot/jtreg/gc/TestNUMAPageSize.java
>     @@ -27,7 +27,8 @@
>         * @summary Make sure that start up with NUMA support does not cause
>     problems.
>         * @bug 8061467
>         * @requires vm.opt.AggressiveOpts != true
>     - * @run main/othervm -Xmx128m -XX:+UseNUMA TestNUMAPageSize
>     + * @requires vm.gc != "Z"
>     + * @run main/othervm -Xmx128m -XX:+UseNUMA -XX:+UseLargePages
>     TestNUMAPageSize
>         */
> 
>        public class TestNUMAPageSize {
> 
> 
>     cheers,
>     Per
> 
> 
>      >
>      > Thanks,
>      >    Thomas
>      >
>      > On Mon, 2018-08-13 at 10:23 +0200, Thomas Schatzl wrote:
>      >> Hi,
>      >>
>      >> On Mon, 2018-08-13 at 09:58 +0200, Per Liden wrote:
>      >>> Hmm, I suspect this might fail on many Linux systems, since it
>      >>> might require configuring the huge page pool with enough pages.
>      >>
>      >>    from my understanding -XX:+UseLargePages will just give some
>      >> warnings
>      >>   at startup if it can not allocate pages. It will not fail.
>      >>
>      >> Assuming that the intent is to check whether when trying to use
>     large
>      >> pages (and the machine is properly configured), does not in any way
>      >> make the VM crash, the warnings can be ignored.
>      >>
>      >> I am not aware there is a way to run tests on machines only that
>     have
>      >> the property "properly configured large pages" at this time.
>      >>
>      >> Thanks,
>      >>    Thomas
>      >>
>      >
> 
> 
> 
> -- 
> 
> Thanks,
> Jc