gc log analysis tools
neojia at gmail.com
Thu Oct 25 23:13:40 PDT 2007
Which one should be better? lower score or higher score? I assume it
should be higher based on what you said here.
And, what is the relation between score and time? Will the execution
time longer with a low score?
And how many minor GC and full GC in each of your execution? Just grep
and wc them.
For 32-bit and 64-bit machine, at least the default heap layout is
different. Are you trying to use same amount of nursery space and
And for 64-bit machine, the Jitter is much more better than 32-bit
machine, a lot of optimization is added.
On 10/25/07, Ben Cheng <bccheng at google.com> wrote:
> The reason I am interested in this information is because I have a benchmark
> whose score is X using 32-bit VM and 2G of heap. When I switched to 64-bit
> build of the same VM, the score dropped to 0.77X with the same amount of
> heap. If I increase the heap size to 3.5G (on a machine with 4GB of RAM),
> the score went to to 1.40X.
> What I need is pretty basic - it sums up all the gc time from the verbose
> log during a benchmark run, as I want to verify if the change in gc time
> correlates to the change in performance. I can write a similar script to do
> that, but I just want to check to see if there is a working tool out there
> already. Apparently the verbose gc log format changed from 1.5 and beyond
> and the old script is not compatible.
> On 10/25/07, Neo Jia <neojia at gmail.com> wrote:
> > Ben,
> > What is your opion? I had one but not sure if it would work for you or not
> > I have not worked on JDK for a while ...
> > Thanks,
> > Neo
> > On 10/25/07, Ben Cheng < bccheng at google.com> wrote:
> > > Hi,
> > >
> > > I was trying to get a sense of total GC time spent in a Java app using
> > > JDK. The gc logs (w/ and wo/ parallel gc) seem to break the ancient tool
> > > gc_analyze.pl found on the web.
> > >
> > > Is there an update to date tool to produce the desired information for
> > > JDKs?
> > >
> > > Thanks in advance,
> > > -Ben
> > >
> > --
> > I would remember that if researchers were not ambitious
> > probably today we haven't the technology we are using!
I would remember that if researchers were not ambitious
probably today we haven't the technology we are using!
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