From stefan.karlsson at oracle.com Thu Sep 1 10:15:40 2022 From: stefan.karlsson at oracle.com (Stefan Karlsson) Date: Thu, 1 Sep 2022 12:15:40 +0200 Subject: CFV: New ZGC Committer: Axel Boldt-Christmas Message-ID: <94b8c292-a5fa-27ad-dc01-0d3f39c85878@oracle.com> |I hereby nominate Axel Boldt-Christmas to ZGC Committer. Axel is a new member of the Oracle HotSpot GC team. He's been contributing cleanups, fixes, and performance optimizations to the Generational ZGC branch. Votes are due by 2022-09-15T12:08+02:00. Only current ZGC Committers [1] are eligible to vote on this nomination. Votes must be cast in the open by replying to this mailing list. For Lazy Consensus voting instructions, see [2]. StefanK [1] https://openjdk.org/census [2] https://openjdk.org/projects/#committer-vote https://github.com/openjdk/zgc/commit/80651e0f92ecc6345d5f630ba22c27e939d130f1 https://github.com/openjdk/zgc/commit/ed3419132a6b7b0662131f1d5e8cf759585f059d https://github.com/openjdk/zgc/commit/2c46ada6d8d62f2d2506482aa9581767eea62501 https://github.com/openjdk/zgc/commit/5b9ce45ad082757609162f7036cd5c699234db78 https://github.com/openjdk/zgc/commit/d1fcecad9c9160c504d4c87a208fc9d4dafb26ba https://github.com/openjdk/zgc/commit/73ec88a4630667fd7d6ffa3efae5ea96146667a7 https://github.com/openjdk/zgc/commit/87167f31ec8167669d7c957b5690d342dcc42d7d https://github.com/openjdk/zgc/commit/5e8fdac23234cc9023f57bc679dae0701f4041c9 https://github.com/openjdk/zgc/commit/fd84f30c1b5683fece603b04b333986b2dfc95a1 https://github.com/openjdk/zgc/commit/f4ae372695fd3b5864807e64d56473a47a31b43f | -------------- next part -------------- An HTML attachment was scrubbed... URL: From erik.osterlund at oracle.com Thu Sep 1 10:21:57 2022 From: erik.osterlund at oracle.com (Erik Osterlund) Date: Thu, 1 Sep 2022 10:21:57 +0000 Subject: CFV: New ZGC Committer: Axel Boldt-Christmas In-Reply-To: <94b8c292-a5fa-27ad-dc01-0d3f39c85878@oracle.com> References: <94b8c292-a5fa-27ad-dc01-0d3f39c85878@oracle.com> Message-ID: Vote: yes /Erik On 1 Sep 2022, at 13:16, Stefan Karlsson wrote: ? I hereby nominate Axel Boldt-Christmas to ZGC Committer. Axel is a new member of the Oracle HotSpot GC team. He's been contributing cleanups, fixes, and performance optimizations to the Generational ZGC branch. Votes are due by 2022-09-15T12:08+02:00. Only current ZGC Committers [1] are eligible to vote on this nomination. Votes must be cast in the open by replying to this mailing list. For Lazy Consensus voting instructions, see [2]. StefanK [1] https://openjdk.org/census [2] https://openjdk.org/projects/#committer-vote https://github.com/openjdk/zgc/commit/80651e0f92ecc6345d5f630ba22c27e939d130f1 https://github.com/openjdk/zgc/commit/ed3419132a6b7b0662131f1d5e8cf759585f059d https://github.com/openjdk/zgc/commit/2c46ada6d8d62f2d2506482aa9581767eea62501 https://github.com/openjdk/zgc/commit/5b9ce45ad082757609162f7036cd5c699234db78 https://github.com/openjdk/zgc/commit/d1fcecad9c9160c504d4c87a208fc9d4dafb26ba https://github.com/openjdk/zgc/commit/73ec88a4630667fd7d6ffa3efae5ea96146667a7 https://github.com/openjdk/zgc/commit/87167f31ec8167669d7c957b5690d342dcc42d7d https://github.com/openjdk/zgc/commit/5e8fdac23234cc9023f57bc679dae0701f4041c9 https://github.com/openjdk/zgc/commit/fd84f30c1b5683fece603b04b333986b2dfc95a1 https://github.com/openjdk/zgc/commit/f4ae372695fd3b5864807e64d56473a47a31b43f -------------- next part -------------- An HTML attachment was scrubbed... URL: From stefan.karlsson at oracle.com Thu Sep 1 13:27:43 2022 From: stefan.karlsson at oracle.com (Stefan Karlsson) Date: Thu, 1 Sep 2022 15:27:43 +0200 Subject: CFV: New ZGC Committer: Axel Boldt-Christmas In-Reply-To: <94b8c292-a5fa-27ad-dc01-0d3f39c85878@oracle.com> References: <94b8c292-a5fa-27ad-dc01-0d3f39c85878@oracle.com> Message-ID: <62adc912-ecf1-4df3-2bac-962aae62c9f4@oracle.com> Vote: yes StefanK On 2022-09-01 12:15, Stefan Karlsson wrote: > |I hereby nominate Axel Boldt-Christmas to ZGC Committer. Axel is a > new member of the Oracle HotSpot GC team. He's been contributing > cleanups, fixes, and performance optimizations to the Generational ZGC > branch. Votes are due by 2022-09-15T12:08+02:00. Only current ZGC > Committers [1] are eligible to vote on this nomination. Votes must be > cast in the open by replying to this mailing list. For Lazy Consensus > voting instructions, see [2]. StefanK [1] https://openjdk.org/census > [2] https://openjdk.org/projects/#committer-vote > https://github.com/openjdk/zgc/commit/80651e0f92ecc6345d5f630ba22c27e939d130f1 > https://github.com/openjdk/zgc/commit/ed3419132a6b7b0662131f1d5e8cf759585f059d > https://github.com/openjdk/zgc/commit/2c46ada6d8d62f2d2506482aa9581767eea62501 > https://github.com/openjdk/zgc/commit/5b9ce45ad082757609162f7036cd5c699234db78 > https://github.com/openjdk/zgc/commit/d1fcecad9c9160c504d4c87a208fc9d4dafb26ba > https://github.com/openjdk/zgc/commit/73ec88a4630667fd7d6ffa3efae5ea96146667a7 > https://github.com/openjdk/zgc/commit/87167f31ec8167669d7c957b5690d342dcc42d7d > https://github.com/openjdk/zgc/commit/5e8fdac23234cc9023f57bc679dae0701f4041c9 > https://github.com/openjdk/zgc/commit/fd84f30c1b5683fece603b04b333986b2dfc95a1 > https://github.com/openjdk/zgc/commit/f4ae372695fd3b5864807e64d56473a47a31b43f > | -------------- next part -------------- An HTML attachment was scrubbed... URL: From 920378797 at qq.com Mon Sep 5 09:19:38 2022 From: 920378797 at qq.com (=?utf-8?B?6IuX5piM5a6H?=) Date: Mon, 5 Sep 2022 17:19:38 +0800 Subject: Why does the Subphase weak roots JVMTIWeakExport is always increasing? Message-ID: When I use ZGC on JDK11.0.8 in an online service, I find the time of Subphase weak roots JVMTIWeakExport is always increasing as our service is running. I want to know want made that? Hope you will teach me. -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: ?????-1.png Type: image/png Size: 167388 bytes Desc: not available URL: From stefan.karlsson at oracle.com Mon Sep 5 12:41:47 2022 From: stefan.karlsson at oracle.com (Stefan Karlsson) Date: Mon, 5 Sep 2022 14:41:47 +0200 Subject: Why does the Subphase weak roots JVMTIWeakExport is always increasing? In-Reply-To: References: Message-ID: <81c33904-1661-b2df-0e25-c179b74c8dd1@oracle.com> My guess is that you have some kind of JVMTI agent that adds objects tags. See: https://docs.oracle.com/en/java/javase/11/docs/specs/jvmti.html#objectTags The JVM holds an internal hashmap from object to tags. In older ZGCs releases we updated the object references in that hashmap during a pause. This was later moved to a concurrent phase with https://bugs.openjdk.org/browse/JDK-8212879. StefanK On 2022-09-05 11:19, ??? wrote: > When I use ZGC on JDK11.0.8 in an online service, I find the time of > Subphase weak roots JVMTIWeakExport is always increasing as our > service is running. I want to know want made that? > Hope you will teach me. > -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: %E7%B2%98%E8%B4%B4%E7%9A%84%E5%9B%BE%E5%BD%A2-1.png Type: image/png Size: 167388 bytes Desc: not available URL: From kim.barrett at oracle.com Sat Sep 10 19:37:12 2022 From: kim.barrett at oracle.com (Kim Barrett) Date: Sat, 10 Sep 2022 19:37:12 +0000 Subject: CFV: New ZGC Committer: Axel Boldt-Christmas In-Reply-To: <94b8c292-a5fa-27ad-dc01-0d3f39c85878@oracle.com> References: <94b8c292-a5fa-27ad-dc01-0d3f39c85878@oracle.com> Message-ID: <7330E364-67E5-41C1-A0BA-9050844E2782@oracle.com> vote: yes > On Sep 1, 2022, at 6:15 AM, Stefan Karlsson wrote: > > I hereby nominate Axel Boldt-Christmas to ZGC Committer. > > Axel is a new member of the Oracle HotSpot GC team. He's been > contributing cleanups, fixes, and performance optimizations to > the Generational ZGC branch. > > Votes are due by 2022-09-15T12:08+02:00. > > Only current ZGC Committers [1] are eligible to vote > on this nomination. Votes must be cast in the open by replying > to this mailing list. > > For Lazy Consensus voting instructions, see [2]. > > StefanK > > [1] > https://openjdk.org/census > > [2] > https://openjdk.org/projects/#committer-vote > > > > https://github.com/openjdk/zgc/commit/80651e0f92ecc6345d5f630ba22c27e939d130f1 > https://github.com/openjdk/zgc/commit/ed3419132a6b7b0662131f1d5e8cf759585f059d > https://github.com/openjdk/zgc/commit/2c46ada6d8d62f2d2506482aa9581767eea62501 > https://github.com/openjdk/zgc/commit/5b9ce45ad082757609162f7036cd5c699234db78 > https://github.com/openjdk/zgc/commit/d1fcecad9c9160c504d4c87a208fc9d4dafb26ba > https://github.com/openjdk/zgc/commit/73ec88a4630667fd7d6ffa3efae5ea96146667a7 > https://github.com/openjdk/zgc/commit/87167f31ec8167669d7c957b5690d342dcc42d7d > https://github.com/openjdk/zgc/commit/5e8fdac23234cc9023f57bc679dae0701f4041c9 > https://github.com/openjdk/zgc/commit/fd84f30c1b5683fece603b04b333986b2dfc95a1 > https://github.com/openjdk/zgc/commit/f4ae372695fd3b5864807e64d56473a47a31b43f From stefan.karlsson at oracle.com Mon Sep 19 13:01:46 2022 From: stefan.karlsson at oracle.com (Stefan Karlsson) Date: Mon, 19 Sep 2022 15:01:46 +0200 Subject: Result: New ZGC Committer: Axel Boldt-Christmas Message-ID: Voting for Axel Boldt-Christmas [1] is now closed. Yes: 3 Veto: 0 Abstain: 0 According to the Bylaws definition of Lazy Consensus, this is sufficient to approve the nomination. StefanK [1] https://mail.openjdk.org/pipermail/zgc-dev/2022-September/001142.html From 404450559 at qq.com Wed Sep 21 06:34:07 2022 From: 404450559 at qq.com (=?gb18030?B?tdjJz7XE1MLTsA==?=) Date: Wed, 21 Sep 2022 14:34:07 +0800 Subject: out of address space Message-ID: Hi everyone     these days when I use zgc with jdk17, after the app run for a few days, I meet a "out of address space" problem, and cpu raise to nearly 100%, looks like there is infinite loop. Out of address space Force to lower max java heap size from 50G(100%) to 50G(100%) Out of address space Force to lower max java heap size from 50G(100%) to 50G(100%) Out of address space Force to lower max java heap size from 50G(100%) to 50G(100%) after I check the source code, it looks like the problem is in the function ZPageAllocator::alloc_page -> retry loop my profile flame graph also shows that the most cpu take func is alloc_page_finalize ZPageAllocator::alloc_page_finalize 91.92% ZPageAllocator::alloc_page_create 91.92% ZVirtualMemoryManager::alloc 90.85% ZMemoryManager::alloc_from_back 89.07% I have tried to add this fragment patch but it seems not usefulhttps://bugs.openjdk.org/browse/JDK-8276055how can I fix this or debug this? looking forward to your answers.best wishes? -Anjian Wen -------------- next part -------------- An HTML attachment was scrubbed... URL: From erik.osterlund at oracle.com Tue Sep 27 08:15:15 2022 From: erik.osterlund at oracle.com (Erik Osterlund) Date: Tue, 27 Sep 2022 08:15:15 +0000 Subject: out of address space In-Reply-To: References: Message-ID: <055282A9-5C24-4D81-A97F-E5F67D597F7D@oracle.com> Hi Anjian, Thank you for reporting this issue. I have filed a bug for investigating this: https://bugs.openjdk.org/browse/JDK-8294425 Based on the reported symptoms, it smells like the virtual address space has gotten fragmented over time, possibly due to large allocations that are too large to move around. We do reserve ?a bunch? of extra virtual address space to deal with that, but perhaps something is flawed in that logic, and you have hit some kind of corner case. If you run -Xlog:gc+init, then we can see how much address space was reserved by the GC when the JVM started. This information would be very useful to further reason about what has happened. So if we could get the output of that logging, that would be great. As a workaround for now, if you would like to force ZGC to reserve more virtual address space, you can use the following JVM flags: -Xmx50G -XX:SoftMaxHeapSize=50G -Xmx1T Then ZGC is forced to reserve virtual memory as if the heap could grow to 1T, while in fact, the SoftMaxHeapSize will limit heap growth past 50G unless the GC can?t keep up. This will ensure that the GC has tons of virtual address space at its disposal. If you still run out of virtual address space, then the issue is probably not due to virtual address space fragmentation. Thanks, /Erik On 21 Sep 2022, at 08:34, ????? <404450559 at qq.com> wrote: Hi everyone these days when I use zgc with jdk17, after the app run for a few days, I meet a "out of address space" problem, and cpu raise to nearly 100%, looks like there is infinite loop. Out of address space Force to lower max java heap size from 50G(100%) to 50G(100%) Out of address space Force to lower max java heap size from 50G(100%) to 50G(100%) Out of address space Force to lower max java heap size from 50G(100%) to 50G(100%) after I check the source code, it looks like the problem is in the function ZPageAllocator::alloc_page -> retry loop my profile flame graph also shows that the most cpu take func is alloc_page_finalize ZPageAllocator::alloc_page_finalize 91.92% ZPageAllocator::alloc_page_create 91.92% ZVirtualMemoryManager::alloc 90.85% ZMemoryManager::alloc_from_back 89.07% I have tried to add this fragment patch but it seems not useful https://bugs.openjdk.org/browse/JDK-8276055 how can I fix this or debug this? looking forward to your answers. best wishes? -Anjian Wen -------------- next part -------------- An HTML attachment was scrubbed... URL: From 404450559 at qq.com Tue Sep 27 08:51:57 2022 From: 404450559 at qq.com (=?gb18030?B?tdjJz7XE1MLTsA==?=) Date: Tue, 27 Sep 2022 16:51:57 +0800 Subject: =?gb18030?B?UmWjuiBvdXQgb2YgYWRkcmVzcyBzcGFjZQ==?= Message-ID: Hi Erik Thanks for your answer, after last time report, I have tried add some logs together with the fragment patch https://bugs.openjdk.org/browse/JDK-8276055. maybe because of last time I haven't built the jdk17 right, I can't reproduce the problem until now this time(the apps running about 3 days, maybe not enough time), I will keep observing for a while. If it happens again, I will add -Xlog:gc+init and -XX:SoftMaxHeapSize to find more information and give the result data for analysis. However, since the time it takes to reproduce the problem maybe a week or more, I will report the observation in 2 weeks to let you know the result. Thanks again Anjian ------------------ ???? ------------------ ???: "Erik Osterlund"