Hello, everyone. Looking at the code. It looks like ZGC uses a single threaded PreTouch. Both the G1 and Shenandoah use a parallel PreTouch. Any plans to make ZGC PreTouch parallel? Apologies if I missed something in the code. But I am seeing G1 do the pretouch much faster than ZGC for the same heap size. Thank you. Alen
Hi, On Sun, 2019-12-01 at 22:03 +0100, Alen Vrečko wrote:
Hello, everyone.
Looking at the code. It looks like ZGC uses a single threaded PreTouch. Both the G1 and Shenandoah use a parallel PreTouch.
Any plans to make ZGC PreTouch parallel? Apologies if I missed something in the code. But I am seeing G1 do the pretouch much faster than ZGC for the same heap size.
the change for this (https://bugs.openjdk.java.net/browse/JDK-8234543 ) is currently in review. Thanks, Thomas
Hi, Thomas. Thank you for the quick response. Hope to see this implemented soon. It is a small code change that makes a noticeable difference in startup time. Let me know if you are open for code contribution. Alen V V ned., 1. dec. 2019 ob 22:06 je oseba Thomas Schatzl <thomas.schatzl@oracle.com> napisala:
Hi,
On Sun, 2019-12-01 at 22:03 +0100, Alen Vrečko wrote:
Hello, everyone.
Looking at the code. It looks like ZGC uses a single threaded PreTouch. Both the G1 and Shenandoah use a parallel PreTouch.
Any plans to make ZGC PreTouch parallel? Apologies if I missed something in the code. But I am seeing G1 do the pretouch much faster than ZGC for the same heap size.
the change for this (https://bugs.openjdk.java.net/browse/JDK-8234543 ) is currently in review.
Thanks, Thomas
On 2019-12-01 22:06, Thomas Schatzl wrote:
Hi,
On Sun, 2019-12-01 at 22:03 +0100, Alen Vrečko wrote:
Hello, everyone.
Looking at the code. It looks like ZGC uses a single threaded PreTouch. Both the G1 and Shenandoah use a parallel PreTouch.
Any plans to make ZGC PreTouch parallel? Apologies if I missed something in the code. But I am seeing G1 do the pretouch much faster than ZGC for the same heap size.
the change for this (https://bugs.openjdk.java.net/browse/JDK-8234543 ) is currently in review.
And here's the review thread, with the patch: http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2019-November/027885.h... I've been holding off pushing this to avoid conflicts with the Windows port. We expect to push both within the next few days. cheers, Per
Awesome! Thank you for the great work with ZGC! I am used of seeing commits linked with Jira issues. Got confused. Never mind. All good. Cheers Alen On Sun, 1 Dec 2019 at 22:30, Per Liden <per.liden@oracle.com> wrote:
On 2019-12-01 22:06, Thomas Schatzl wrote:
Hi,
On Sun, 2019-12-01 at 22:03 +0100, Alen Vrečko wrote:
Hello, everyone.
Looking at the code. It looks like ZGC uses a single threaded PreTouch. Both the G1 and Shenandoah use a parallel PreTouch.
Any plans to make ZGC PreTouch parallel? Apologies if I missed something in the code. But I am seeing G1 do the pretouch much faster than ZGC for the same heap size.
the change for this (https://bugs.openjdk.java.net/browse/JDK-8234543 ) is currently in review.
And here's the review thread, with the patch:
http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2019-November/027885.h...
I've been holding off pushing this to avoid conflicts with the Windows port. We expect to push both within the next few days.
cheers, Per
participants (3)
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Alen Vrečko
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Per Liden
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Thomas Schatzl