<div dir="ltr">Yes. That's it. Likewise, it would be nice to have a flag to turn off tenuring threshold adaptiveness on CMS.<div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Mar 9, 2015 at 11:07 PM, Jon Masamitsu <span dir="ltr"><<a href="mailto:jon.masamitsu@oracle.com" target="_blank">jon.masamitsu@oracle.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div bgcolor="#FFFFFF" text="#000000"><span class="">
    <br>
    <div>On 3/9/2015 10:39 PM, Jungwoo Ha wrote:<br>
    </div>
    <blockquote type="cite">
      <div dir="ltr">We were investigating some features and figured out
        that ParallelScavange and ParNew has different TenuringTreshold
        heuristics.
        <div>We thought it would be nice to have a flag that can control
          the adaptiveness, so that we can fix it on purpose to isolate
          other performance factors.</div>
      </div>
    </blockquote>
    <br></span>
    Do you use UsePSAdaptiveSurvivorSizePolicy to turn off the <br>
    survivor space resizing and tenuring threshold adaptiveness<br>
    for ParallelGC?<span class="HOEnZb"><font color="#888888"><br>
    <br>
    Jon</font></span><div><div class="h5"><br>
    <br>
    <blockquote type="cite">
      <div dir="ltr">
        <div>--Jungwoo</div>
      </div>
      <div class="gmail_extra"><br>
        <div class="gmail_quote">On Mon, Mar 9, 2015 at 11:27 AM, Jon
          Masamitsu <span dir="ltr"><<a href="mailto:jon.masamitsu@oracle.com" target="_blank">jon.masamitsu@oracle.com</a>></span>
          wrote:<br>
          <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div bgcolor="#FFFFFF" text="#000000"> Jungwoo,<span><br>
                <br>
                <div>On 03/06/2015 06:03 PM, Jungwoo Ha wrote:<br>
                </div>
                <blockquote type="cite">
                  <div dir="ltr">I think it is the same for all
                    JDK{7,8,9}.
                    <div><br>
                    </div>
                    <div>arguments.cpp disabled UseAdaptiveSizePolicy
                      for CMS.</div>
                    <div>parallel scavange initializes
                      _tenuring_threshold with</div>
                    <div>  _tenuring_threshold = (UseAdaptiveSizePolicy)
                      ? InitialTenuringThreshold : MaxTenuringThreshold;</div>
                    <div>whereas CMS uses</div>
                    <div>  _tenuring_threshold = MaxTenuringThreshold;</div>
                    <div><br>
                    </div>
                    <div>adjust_desired_tenuring_threshold() is called
                      inside ParNewGeneration::collect(), which calls
                      compute_tenuring_threshold.</div>
                    <div>It only uses MaxTenuringThreshold and
                      TargetSurvivorRatio.</div>
                    <div>I don't see any other flags here.<br>
                    </div>
                  </div>
                </blockquote>
                <br>
              </span> Yes, this is the intended behavior.<br>
              <br>
              You're saying we're sometimes wasting survivor space?<span><font color="#888888"><br>
                  <br>
                  Jon</font></span><span><br>
                <br>
                <blockquote type="cite">
                  <div class="gmail_extra"><br>
                    <div class="gmail_quote">On Fri, Mar 6, 2015 at 4:28
                      PM, Jon Masamitsu <span dir="ltr"><<a href="mailto:jon.masamitsu@oracle.com" target="_blank">jon.masamitsu@oracle.com</a>></span>
                      wrote:<br>
                      <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">This is in jdk9?<span><font color="#888888"><br>
                            <br>
                            Jon</font></span>
                        <div>
                          <div><br>
                            <br>
                            On 3/6/2015 4:21 PM, Jungwoo Ha wrote:<br>
                            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> On CMS when
                              UseAdaptiveSizePolicy is off, still
                              tenuring_threshold is being changed.<br>
                              Is this an intended behavior?<br>
                              (yes. I know it is not "size" related
                              heuristics)<br>
                              <br>
                              It would be nice to have a flag that can
                              disable adjusting tenuring threshold,<br>
                              or at least set minimum threshold. When
                              the default heuristics doesn't work,<br>
                              there are nothing much we can do other
                              than changing the Max.<br>
                              <br>
                              --Jungwoo<br>
                            </blockquote>
                            <br>
                          </div>
                        </div>
                      </blockquote>
                    </div>
                    <br>
                  </div>
                </blockquote>
                <br>
              </span></div>
          </blockquote>
        </div>
        <br>
      </div>
    </blockquote>
    <br>
  </div></div></div>

</blockquote></div><br></div>