<html><head><style>body{font-family:Helvetica,Arial;font-size:13px}</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">Thanks for the heads up Jungwoo. I think it should be straightforward to decide whether to unload classes for a particular CMS cycle based on the rate at which the meatspace occupancy is growing. Has anyone considered / looked into this?</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">Tony</div> <br><p class="airmail_on">On March 10, 2016 at 7:07:00 PM, Jungwoo Ha (<a href="mailto:jwha@google.com">jwha@google.com</a>) wrote:</p> <blockquote type="cite" class="clean_bq"><span><div><div></div><div>
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<div dir="ltr">We've been disabled CMSClassUnloading for a long
time and had no issues.
<div>We recently turned it back on by default with
CMSClassUnloadingMaxInterval=5, which amortizes the increased
remark cost.<br>
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<div class="gmail_quote">On Thu, Mar 10, 2016 at 1:32 PM, Tony
Printezis <span dir="ltr"><<a href="mailto:tprintezis@twitter.com" target="_blank">tprintezis@twitter.com</a>></span> wrote:<br>
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Hi all,</div>
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<div style="font-family:Helvetica,Arial;font-size:13px;color:rgba(0,0,0,1.0);margin:0px;line-height:auto">
CMSClassUnloadingEnabled is enabled by default in JDK 8. Most of
our services do not require class unloading (they load a bunch of
classes up-front and that’s it) so we’re thinking of turning it off
by default in our JDK as it increases our remark times by a
non-trivial amount (40-90ms depending on the service). Any known
issues with running with -XX:-CMSClassUnloadingEnabled? (This is a
veiled way to ask: is anyone testing with that flag off?)</div>
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Thanks,</div>
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<div style="font-family:Helvetica,Arial;font-size:13px;color:rgba(0,0,0,1.0);margin:0px;line-height:auto">
Tony</div>
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<div>Tony Printezis | JVM/GC Engineer / VM Team | Twitter</div>
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<div>@TonyPrintezis</div>
<div><a href="mailto:tprintezis@twitter.com" target="_blank">tprintezis@twitter.com</a></div>
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<div><span style="font-size:12.8000001907349px">Jungwoo Ha | Java
Platform Team | <a href="mailto:jwha@google.com" target="_blank">jwha@google.com</a></span><br></div>
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</div></div></span></blockquote> <div id="bloop_sign_1457712622265373952" class="bloop_sign"><div style="font-family:helvetica,arial;font-size:13px"><div>-----</div><div><br></div><div>Tony Printezis | JVM/GC Engineer / VM Team | Twitter</div><div><br></div><div>@TonyPrintezis</div><div><a href="mailto:tprintezis@twitter.com">tprintezis@twitter.com</a></div><div><br></div></div></div></body></html>