<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;">Hi Jon,</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;">Thanks for giving it a spin. Yes, we do have specjbb2013. I’m at ECOOP / CurryOn this week. I’ll try this on Monday after I get back home. Thanks again,</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" style="color:#000;">On July 7, 2015 at 9:10:12 PM, Jon Masamitsu (<a href="mailto:jon.masamitsu@oracle.com">jon.masamitsu@oracle.com</a>) wrote:</p> <blockquote type="cite" class="clean_bq"><span><div bgcolor="#FFFFFF" text="#000000"><div></div><div>
<title></title>
Tony,<br>
<br>
Are you setup to run specjbb2013? I did a run with<br>
<br>
the PerStride changes (original patch) vs a baseline and<br>
saw an increase in ParNew times. I attached a plot of
the<br>
pause times. I used<br>
<br>
-server -Xmx30g -Xms30g -Xmn20g -XX:+UseConcMarkSweepGC
-XX:+UseLargePages<br>
<br>
This was run on a linux system with 8 cores.<br>
<br>
From a run of specjbb2005 on the same system there is an
improvement<br>
in the ParNew times.<br>
<br>
I'll repeat the experiment with the latest patch. If
you can try to repeat the experiment,<br>
that would give me some confidence that it's not just me.<br>
<br>
Thanks.<br>
<br>
Jon<br>
<br>
<br>
<div class="moz-cite-prefix">On 07/02/2015 12:39 PM, Tony Printezis
wrote:<br></div>
<blockquote cite="mid:etPan.5595937a.283b46fd.386@tw-mbp-tprintezis" type="cite">
<div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">
Thomas,</div>
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<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;">
Latest version:</div>
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<br></div>
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<a moz-do-not-send="true" href="http://cr.openjdk.java.net/%7Etonyp/8086056/webrev.3/">http://cr.openjdk.java.net/~tonyp/8086056/webrev.3/</a></div>
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<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;">
See below for comments.</div>
<br>
<p class="airmail_on" style="color:#000;">On July 2, 2015 at
4:43:42 AM, Thomas Schatzl (<a moz-do-not-send="true" href="mailto:thomas.schatzl@oracle.com">thomas.schatzl@oracle.com</a>)
wrote:</p>
<div>
<blockquote type="cite" class="clean_bq" style="color: rgb(0, 0, 0); font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
<div>
<div><span>Hi Tony,<span class="Apple-converted-space"> </span><br>
<br>
On Wed, 2015-07-01 at 18:05 -0400, Tony Printezis
wrote:<span class="Apple-converted-space"> </span><br>
> Latest changes, as discussed with Bengt and
Thomas,<span class="Apple-converted-space"> </span><br>
><span class="Apple-converted-space"> </span><br>
> <a class="moz-txt-link-freetext" href="http://cr.openjdk.java.net/~tonyp/8086056/webrev.2/">http://cr.openjdk.java.net/~tonyp/8086056/webrev.2/</a><span class="Apple-converted-space"> </span><br>
<br>
a few suggestions:<span class="Apple-converted-space"> </span><br>
<br>
- please use braces even for simple statements in if-clauses,
e.g.<span class="Apple-converted-space"> </span></span></div>
</div>
</blockquote>
</div>
<div>
<div>
<blockquote type="cite" class="clean_bq" style="color: rgb(0, 0, 0); font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
<div>
<div><span><br>
parNewGeneration.cpp:<span class="Apple-converted-space"> </span><br>
<br>
883 if (!UseDynamicParGCStrides) return;<span class="Apple-converted-space"> </span></span></div>
</div>
</blockquote>
</div>
<p><br></p>
<p>I did that. But I actually added an extra verbose statement in
the body of the if-statement (I thought it’d be helpful to also
print the value of ParGCCardsPerStrideChunk when the dynamic
calculation is off). So, I don’t have a simple return any more, but
I’ll keep that in mind in the future (was it anywhere else? I
didn’t immediately spot another occurrence of that).</p>
<p><br></p>
<div>
<div>
<blockquote type="cite" class="clean_bq" style="color: rgb(0, 0, 0); font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
<div>
<div><span><br>
- Comments should start with upper case:<span class="Apple-converted-space"> </span><br>
<br>
parNewGeneration.hpp:<span class="Apple-converted-space"> </span><br>
<br>
354 // automatically calculate ParGCCardsPerStrideChunk based on
the<span class="Apple-converted-space"> </span><br>
old<span class="Apple-converted-space"> </span></span></div>
</div>
</blockquote>
</div>
<p><br></p>
<p>Done.</p>
<p><br></p>
<div>
<div>
<blockquote type="cite" class="clean_bq" style="color: rgb(0, 0, 0); font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
<div>
<div><span><br>
- parameter calculation in
ParNewGeneration::adjust_cards_per_stride:<span class="Apple-converted-space"> </span><br>
- DynamicParGCStridesMinSize should be > 0 (only if
!<span class="Apple-converted-space"> </span><br>
UseDynamicParGCStrides is enabled, not sure if that can be
encoded<span class="Apple-converted-space"> </span><br>
within the framework)<span class="Apple-converted-space"> </span></span></div>
</div>
</blockquote>
</div>
<p><br></p>
<p>If !UseDynamicParGCStrides, then both sets of min / max
parameters are not used. I think it’d make the constraint checking
a pain having to sanity-check parameters whether a flag is on or
off (unless they mean different things in either case, of
course).</p>
<p>I added a range check to the min / max stride size args, added a
lower bound of 1, and decided to add an artificial upper bound of
32K (I have tested with up to 8K). Is that reasonable? We can
revisit that if we need to increse it. Note that you can still set
ParGCCardsPerStrideChunk to something higher if required.</p>
<p><br></p>
<div>
<div>
<blockquote type="cite" class="clean_bq" style="color: rgb(0, 0, 0); font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
<div>
<div><span><br>
- the issues with the Dynamic*Capacity variables Sangheon
mentioned,<span class="Apple-converted-space"> </span><br>
although I think it is fine that they are equal, just that "r"
needs to<span class="Apple-converted-space"> </span><br>
be set correctly.<span class="Apple-converted-space"> </span></span></div>
</div>
</blockquote>
</div>
<p><br></p>
<p>Yeah, fixed. (See previous e-mail.)</p>
<p><br></p>
<div>
<div>
<blockquote type="cite" class="clean_bq" style="color: rgb(0, 0, 0); font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
<div>
<div><span><br>
Just wanting to check back if it was intended that the code
always<span class="Apple-converted-space"> </span><br>
rounds down, achieving the maximum stride only at the end of
the<span class="Apple-converted-space"> </span><br>
interval. E.g.<span class="Apple-converted-space"> </span><br>
<br>
912 const int stride_size_log = log2_long((jlong)
stride_size);<span class="Apple-converted-space"> </span><br>
913 res = (size_t) 1 << stride_size_log;<span class="Apple-converted-space"> </span><br>
<br>
It's fine with me, just asking.<span class="Apple-converted-space"> </span></span></div>
</div>
</blockquote>
</div>
<p><br></p>
<p>I did the simplest calculation. I can revise it if you want.
Also note that if capacity > max_capacity, then stride size will
be set to the max stride size.</p>
<p>Tony</p>
<p><br></p>
<div>
<blockquote type="cite" class="clean_bq" style="color: rgb(0, 0, 0); font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
<div>
<div><span><br>
Thanks,<span class="Apple-converted-space"> </span><br>
Thomas<span class="Apple-converted-space"> </span><br>
<br>
<br>
<br></span></div>
</div>
</blockquote>
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<div>-----</div>
<div><br></div>
<div>Tony Printezis | JVM/GC Engineer / VM Team | Twitter</div>
<div><br></div>
<div>@TonyPrintezis</div>
<div><a moz-do-not-send="true" href="mailto:tprintezis@twitter.com">tprintezis@twitter.com</a></div>
<div><br></div>
</div>
</div>
</blockquote>
<br>
<hr></div></div></span></blockquote> <div id="bloop_sign_1436341052357905920" 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>