From qamai at openjdk.org  Fri Aug  1 09:52:33 2025
From: qamai at openjdk.org (Quan Anh Mai)
Date: Fri, 1 Aug 2025 09:52:33 GMT
Subject: [lworld] RFR: 8364191: [lworld] Accesses to atomic flat fields
 prevent scalar replacement [v2]
In-Reply-To: <a9jn2hT7AhnYpWxe1mYYs9JKnq1v-Kc94DRb3D6JgQI=.c185a8f9-50f4-4f16-b9e4-b9a289301701@github.com>
References: <a9jn2hT7AhnYpWxe1mYYs9JKnq1v-Kc94DRb3D6JgQI=.c185a8f9-50f4-4f16-b9e4-b9a289301701@github.com>
Message-ID: <9AdjPfcMo_PPTNaDqRyBBQXsJbmdjeRwS5LzPda_wkY=.7f7b838b-cdcd-4bcb-83d5-2fe6e9496455@github.com>

> Hi,
> 
> Flat accesses prevent scalar replacement because they are mismatched accesses. It is also generally not possible to look through them, because the payload may contain an oop in the form of raw bits. As a result, this PR adds `LoadFlatNode` and `StoreFlatNode`, which act as high-level abstractions for atomic accesses on flat fields. When it is determined that there is no racing access on the flat field (e.g. because the holder object does not escape), these flat access nodes can be expanded into multiple accesses to each flattened fields, otherwise, they will be expanded into a sequence of inferring a payload and accessing memory with that payload.
> 
> I also fix an issue with deoptimization reallocation where we miss assigning the null marker of elements in a nullable flat array.
> 
> Please take a look and leave your reviews, thanks a lot.

Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:

  small fix StoreFlatNode::size_of

-------------

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1518/files
  - new: https://git.openjdk.org/valhalla/pull/1518/files/23828cc7..428b656c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1518&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1518&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/valhalla/pull/1518.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1518/head:pull/1518

PR: https://git.openjdk.org/valhalla/pull/1518

From coleenp at openjdk.org  Fri Aug  1 15:22:36 2025
From: coleenp at openjdk.org (Coleen Phillimore)
Date: Fri, 1 Aug 2025 15:22:36 GMT
Subject: [lworld] RFR: [lworld] Remove redundant DTraceAlloc/Method probes
Message-ID: <6YdvMt4v6E_bxLcdjK3toUTUUnCSOQvANFGEVo7tzS4=.d43baad8-eedf-4fd5-a4d8-9477bb085249@github.com>

Looking through this code, I found this discrepancy.  Tested with some tier1 testing.

-------------

Commit messages:
 - Remove redundant DTraceAlloc/Method probes.

Changes: https://git.openjdk.org/valhalla/pull/1521/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1521&range=00
  Stats: 20 lines in 5 files changed: 0 ins; 17 del; 3 mod
  Patch: https://git.openjdk.org/valhalla/pull/1521.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1521/head:pull/1521

PR: https://git.openjdk.org/valhalla/pull/1521

From thartmann at openjdk.org  Mon Aug  4 19:45:35 2025
From: thartmann at openjdk.org (Tobias Hartmann)
Date: Mon, 4 Aug 2025 19:45:35 GMT
Subject: [lworld] RFR: 8364191: [lworld] Accesses to atomic flat fields
 prevent scalar replacement [v2]
In-Reply-To: <9AdjPfcMo_PPTNaDqRyBBQXsJbmdjeRwS5LzPda_wkY=.7f7b838b-cdcd-4bcb-83d5-2fe6e9496455@github.com>
References: <a9jn2hT7AhnYpWxe1mYYs9JKnq1v-Kc94DRb3D6JgQI=.c185a8f9-50f4-4f16-b9e4-b9a289301701@github.com>
 <9AdjPfcMo_PPTNaDqRyBBQXsJbmdjeRwS5LzPda_wkY=.7f7b838b-cdcd-4bcb-83d5-2fe6e9496455@github.com>
Message-ID: <hlKp6ranoH3nnwwV_4h4JFaU__lA31G32HvCZG5MFn0=.ff7bae4d-b982-4e97-8bd5-276e2e11d0e9@github.com>

On Fri, 1 Aug 2025 09:52:33 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

>> Hi,
>> 
>> Flat accesses prevent scalar replacement because they are mismatched accesses. It is also generally not possible to look through them, because the payload may contain an oop in the form of raw bits. As a result, this PR adds `LoadFlatNode` and `StoreFlatNode`, which act as high-level abstractions for atomic accesses on flat fields. When it is determined that there is no racing access on the flat field (e.g. because the holder object does not escape), these flat access nodes can be expanded into multiple accesses to each flattened fields, otherwise, they will be expanded into a sequence of inferring a payload and accessing memory with that payload.
>> 
>> I also fix an issue with deoptimization reallocation where we miss assigning the null marker of elements in a nullable flat array.
>> 
>> Please take a look and leave your reviews, thanks a lot.
>
> Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:
> 
>   small fix StoreFlatNode::size_of

Thanks for working on this @merykitty! I haven't reviewed this in yet but noticed a build failure:


[2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.cpp: In member function 'void ConnectionGraph::add_final_edges(Node*)':
[2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.cpp:1874:25: error: no matching function for call to 'ConnectionGraph::set_escape_state(PointsToNode*&, PointsToNode::EscapeState, const char [24])'
[2025-08-04T17:23:31,905Z]  1874 |         set_escape_state(field_value_ptn, PointsToNode::GlobalEscape, "store into a flat field");
[2025-08-04T17:23:31,905Z]       |         ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[2025-08-04T17:23:31,905Z] In file included from /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.cpp:38:
[2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.hpp:434:8: note: candidate: 'void ConnectionGraph::set_escape_state(PointsToNode*, PointsToNode::EscapeState)'
[2025-08-04T17:23:31,905Z]   434 |   void set_escape_state(PointsToNode* ptn, PointsToNode::EscapeState esc
[2025-08-04T17:23:31,905Z]       |        ^~~~~~~~~~~~~~~~
[2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.hpp:434:8: note:   candidate expects 2 arguments, 3 provided
[2025-08-04T17:23:32,241Z] lib/CompileJvm.gmk:172: recipe for target '/opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/build/linux-x64/hotspot/variant-server/libjvm/objs/static/escape.o' failed
[2025-08-04T17:23:32,241Z] make[3]: *** [/opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/build/linux-x64/hotspot/variant-server/libjvm/objs/static/escape.o] Error 1

-------------

PR Comment: https://git.openjdk.org/valhalla/pull/1518#issuecomment-3152113964

From liach at openjdk.org  Tue Aug  5 14:12:29 2025
From: liach at openjdk.org (Chen Liang)
Date: Tue, 5 Aug 2025 14:12:29 GMT
Subject: [lworld] RFR: 8360653: [lworld] LayoutIterationTest.java fails
 with -XX:ForceNonTearable=*
In-Reply-To: <uSZPYtwpQQW2sQH0w69cAsJIZl3z0AaG4Abr2nURGpc=.1d983bb0-6d8c-4200-acdb-cf9a2a440897@github.com>
References: <uSZPYtwpQQW2sQH0w69cAsJIZl3z0AaG4Abr2nURGpc=.1d983bb0-6d8c-4200-acdb-cf9a2a440897@github.com>
Message-ID: <-OTFrD7SRDsEA7pZUTN6eCy_hXEUOGvgK0uE5OfWWDI=.04ea2be5-c820-4ae6-9c3f-64e348df474e@github.com>

On Tue, 8 Jul 2025 00:37:38 GMT, Chen Liang <liach at openjdk.org> wrote:

> Mark this test as flagless so we will skip it with any layout perturbation.

Guess people don't bother to review this. I will just integrate.

-------------

PR Comment: https://git.openjdk.org/valhalla/pull/1505#issuecomment-3155390504

From liach at openjdk.org  Tue Aug  5 14:12:29 2025
From: liach at openjdk.org (Chen Liang)
Date: Tue, 5 Aug 2025 14:12:29 GMT
Subject: [lworld] Integrated: 8360653: [lworld] LayoutIterationTest.java fails
 with -XX:ForceNonTearable=*
In-Reply-To: <uSZPYtwpQQW2sQH0w69cAsJIZl3z0AaG4Abr2nURGpc=.1d983bb0-6d8c-4200-acdb-cf9a2a440897@github.com>
References: <uSZPYtwpQQW2sQH0w69cAsJIZl3z0AaG4Abr2nURGpc=.1d983bb0-6d8c-4200-acdb-cf9a2a440897@github.com>
Message-ID: <JGuDzJSaAikyd1Wn79s7E0cAYZpIynhZlIp9p-5s1RQ=.53e1cc88-b337-4cf2-a94b-63d821e7d0f4@github.com>

On Tue, 8 Jul 2025 00:37:38 GMT, Chen Liang <liach at openjdk.org> wrote:

> Mark this test as flagless so we will skip it with any layout perturbation.

This pull request has now been integrated.

Changeset: 67e6bcc4
Author:    Chen Liang <liach at openjdk.org>
URL:       https://git.openjdk.org/valhalla/commit/67e6bcc418721eded34878eb70c7d0a86df338b1
Stats:     1 line in 1 file changed: 1 ins; 0 del; 0 mod

8360653: [lworld] LayoutIterationTest.java fails with -XX:ForceNonTearable=*

-------------

PR: https://git.openjdk.org/valhalla/pull/1505

From fparain at openjdk.org  Wed Aug  6 18:33:33 2025
From: fparain at openjdk.org (Frederic Parain)
Date: Wed, 6 Aug 2025 18:33:33 GMT
Subject: [lworld] RFR: 8364483: [lworld] Pre-register migrated classes in
 class loaders
In-Reply-To: <mMaCSHvc3a7BFIe1U8SpDhP0elNESj4LPVqjcoSNI4U=.d2e5fc2a-0a14-499b-abce-a499d725787d@github.com>
References: <mMaCSHvc3a7BFIe1U8SpDhP0elNESj4LPVqjcoSNI4U=.d2e5fc2a-0a14-499b-abce-a499d725787d@github.com>
Message-ID: <1j2m-tN1ooL4XvU_pdJ5G4Cbxt7xkjosAIsr91f_lY0=.0d514dc6-86b0-4994-8d4c-7b881f1bfafc@github.com>

On Thu, 31 Jul 2025 20:10:14 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> This change preloads and preregisters all classes in the migrated classes lists, in all class loaders.
> Tested with tier1 locally and with -XX:+PrintSystemDictionaryAtExit.

src/hotspot/share/classfile/vmSymbols.hpp line 900:

> 898:   static void migrated_class_names_do(Function f) {
> 899:      for (int i = 0; i < _migrated_class_names_length; i++) {
> 900:        //f->do_symbol(&_migrated_class_names[i]);

Commented line to be removed?

-------------

PR Review Comment: https://git.openjdk.org/valhalla/pull/1520#discussion_r2257963156

From coleenp at openjdk.org  Wed Aug  6 21:48:03 2025
From: coleenp at openjdk.org (Coleen Phillimore)
Date: Wed, 6 Aug 2025 21:48:03 GMT
Subject: [lworld] RFR: 8364483: [lworld] Pre-register migrated classes in
 class loaders [v2]
In-Reply-To: <mMaCSHvc3a7BFIe1U8SpDhP0elNESj4LPVqjcoSNI4U=.d2e5fc2a-0a14-499b-abce-a499d725787d@github.com>
References: <mMaCSHvc3a7BFIe1U8SpDhP0elNESj4LPVqjcoSNI4U=.d2e5fc2a-0a14-499b-abce-a499d725787d@github.com>
Message-ID: <CRCW638JH6jv5NaqAf1pLUrKi3noeyfNh5WEev3I3h0=.011055b0-26cc-4dea-8ea7-68d30fedc158@github.com>

> This change preloads and preregisters all classes in the migrated classes lists, in all class loaders.
> Tested with tier1 locally and with -XX:+PrintSystemDictionaryAtExit.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  remove commented out code.

-------------

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1520/files
  - new: https://git.openjdk.org/valhalla/pull/1520/files/0fd70f7e..1b85463c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1520&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1520&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/valhalla/pull/1520.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1520/head:pull/1520

PR: https://git.openjdk.org/valhalla/pull/1520

From qamai at openjdk.org  Thu Aug  7 13:34:54 2025
From: qamai at openjdk.org (Quan Anh Mai)
Date: Thu, 7 Aug 2025 13:34:54 GMT
Subject: [lworld] RFR: 8364191: [lworld] Accesses to atomic flat fields
 prevent scalar replacement [v3]
In-Reply-To: <a9jn2hT7AhnYpWxe1mYYs9JKnq1v-Kc94DRb3D6JgQI=.c185a8f9-50f4-4f16-b9e4-b9a289301701@github.com>
References: <a9jn2hT7AhnYpWxe1mYYs9JKnq1v-Kc94DRb3D6JgQI=.c185a8f9-50f4-4f16-b9e4-b9a289301701@github.com>
Message-ID: <aXVSCkSXGFnGJO3sVqNKiDEShrzVpZoBAUy6G24ga4o=.414f8352-7a65-4e55-9be4-ee4918077a59@github.com>

> Hi,
> 
> Flat accesses prevent scalar replacement because they are mismatched accesses. It is also generally not possible to look through them, because the payload may contain an oop in the form of raw bits. As a result, this PR adds `LoadFlatNode` and `StoreFlatNode`, which act as high-level abstractions for atomic accesses on flat fields. When it is determined that there is no racing access on the flat field (e.g. because the holder object does not escape), these flat access nodes can be expanded into multiple accesses to each flattened fields, otherwise, they will be expanded into a sequence of inferring a payload and accessing memory with that payload.
> 
> I also fix an issue with deoptimization reallocation where we miss assigning the null marker of elements in a nullable flat array.
> 
> Please take a look and leave your reviews, thanks a lot.

Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:

  fix release build

-------------

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1518/files
  - new: https://git.openjdk.org/valhalla/pull/1518/files/428b656c..eb23f4e5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1518&range=02
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1518&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/valhalla/pull/1518.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1518/head:pull/1518

PR: https://git.openjdk.org/valhalla/pull/1518

From qamai at openjdk.org  Thu Aug  7 13:34:54 2025
From: qamai at openjdk.org (Quan Anh Mai)
Date: Thu, 7 Aug 2025 13:34:54 GMT
Subject: [lworld] RFR: 8364191: [lworld] Accesses to atomic flat fields
 prevent scalar replacement [v2]
In-Reply-To: <hlKp6ranoH3nnwwV_4h4JFaU__lA31G32HvCZG5MFn0=.ff7bae4d-b982-4e97-8bd5-276e2e11d0e9@github.com>
References: <a9jn2hT7AhnYpWxe1mYYs9JKnq1v-Kc94DRb3D6JgQI=.c185a8f9-50f4-4f16-b9e4-b9a289301701@github.com>
 <9AdjPfcMo_PPTNaDqRyBBQXsJbmdjeRwS5LzPda_wkY=.7f7b838b-cdcd-4bcb-83d5-2fe6e9496455@github.com>
 <hlKp6ranoH3nnwwV_4h4JFaU__lA31G32HvCZG5MFn0=.ff7bae4d-b982-4e97-8bd5-276e2e11d0e9@github.com>
Message-ID: <cDnmfPYgLrvZ4bFNtS9F_fH_WfJWzSNFBV770HPTT8M=.1d80023c-b2a9-4844-b4a0-6248de952169@github.com>

On Mon, 4 Aug 2025 19:42:25 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

>> Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   small fix StoreFlatNode::size_of
>
> Thanks for working on this @merykitty! I haven't reviewed this in yet but noticed a build failure:
> 
> 
> [2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.cpp: In member function 'void ConnectionGraph::add_final_edges(Node*)':
> [2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.cpp:1874:25: error: no matching function for call to 'ConnectionGraph::set_escape_state(PointsToNode*&, PointsToNode::EscapeState, const char [24])'
> [2025-08-04T17:23:31,905Z]  1874 |         set_escape_state(field_value_ptn, PointsToNode::GlobalEscape, "store into a flat field");
> [2025-08-04T17:23:31,905Z]       |         ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> [2025-08-04T17:23:31,905Z] In file included from /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.cpp:38:
> [2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.hpp:434:8: note: candidate: 'void ConnectionGraph::set_escape_state(PointsToNode*, PointsToNode::EscapeState)'
> [2025-08-04T17:23:31,905Z]   434 |   void set_escape_state(PointsToNode* ptn, PointsToNode::EscapeState esc
> [2025-08-04T17:23:31,905Z]       |        ^~~~~~~~~~~~~~~~
> [2025-08-04T17:23:31,905Z] /opt/mach5/mesos/work_dir/slaves/f7f8bd65-a387-4a2b-b519-702f2fefaf87-S170287/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/8d44f2d4-5a02-4ac8-95c1-3a37a1d82705/runs/1b653695-e82f-4430-a41f-d099d041486e/workspace/open/src/hotspot/share/opto/escape.hpp:434:8: note:   candidate expects 2 arguments, 3 provided
> [2025-08-04T17:23:32,241Z] lib/CompileJvm.gmk:172: recipe for target '/opt/mach5/mes...

@TobiHartmann Ah dummy mistake, I missed the `NOT_PRODUCT` guard, fixed it now.

-------------

PR Comment: https://git.openjdk.org/valhalla/pull/1518#issuecomment-3164224324