RFR(T) 8219244: NMT: Move safepoint related memory allocations from mtInternal to mtSafepoint

[zgu at redhat.com]

On Tue, 2019-02-19 at 19:38 -0500, coleen.phillimore at oracle.com wrote:
> Yes, this looks good!
> thanks,
> Coleen

Thanks, Coleen.

-Zhengyu

> 
> On 2/19/19 4:32 PM, zgu at redhat.com wrote:
> > On Tue, 2019-02-19 at 16:09 -0500, coleen.phillimore at oracle.com
> > wrote:
> > > On 2/19/19 4:07 PM, zgu at redhat.com wrote:
> > > > Hi Coleen,
> > > > 
> > > > On Tue, 2019-02-19 at 15:13 -0500, coleen.phillimore at oracle.com
> > > > wrote:
> > > > > This is such a small allocation, I think it makes more sense
> > > > > to
> > > > > add
> > > > > it to mtThread.
> > > > 
> > > > I get it if there is not mtSafepoint category, it is not worth
> > > > to
> > > > have
> > > > one for a small allocation, but we already have it. Why is it
> > > > better to
> > > > add to mtThread?
> > > 
> > > Doesn't the current mtSafepoint category only report on mmap
> > > memory
> > > for
> > > the polling page?  This would add a very tiny allocation for the
> > > ThreadSafepointState (maybe too small to report?).
> > 
> > Okay, this makes sense. Probably won't show up if application has
> > only
> > a few JavaThreads.
> > 
> > >   These allocations
> > > really belong to the thread.
> > 
> > I changed bug synopsis to "NMT: Change ThreadSafepointState's
> > allocation type from mtInternal to mtThread"
> > 
> > Updated Webrev: http://cr.openjdk.java.net/~zgu/JDK-8219244/webrev.
> > 01/
> > 
> > Thanks,
> > 
> > -Zhengyu
> > 
> > > Coleen
> > > 
> > > > Thanks,
> > > > 
> > > > -Zhengyu
> > > > 
> > > > 
> > > > Coleen
> > > > > On 2/18/19 3:12 PM, zgu at redhat.com wrote:
> > > > > > There is only one instance I can find.
> > > > > > 
> > > > > > Bug: https://bugs.openjdk.java.net/browse/JDK-8219244
> > > > > > Webrev: http://cr.openjdk.java.net/~zgu/JDK-8219244/webrev.
> > > > > > 00/
> > > > > > 
> > > > > > Test:
> > > > > > 
> > > > > >      hotspot_nmt on Linux x64 (fastdebug and release)
> > > > > >      JDK-submit tests.
> > > > > > 
> > > > > > Thanks,
> > > > > > 
> > > > > > -Zhengyu
> 
>