Zoltan Martonka has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/22977 )

Change subject: [arm64] Fix SIGBUS errors for atomic operations
......................................................................


Patch Set 1:

(2 comments)

Thank you for the change.
Could you tell me what hardware/os are you using? I just want to look at the 
issue, but it seems to be stable both on was graviton and on an arm rhel on Mac 
orbstack.

http://gerrit.cloudera.org:8080/#/c/22977/1/src/kudu/tablet/concurrent_btree.h
File src/kudu/tablet/concurrent_btree.h:

http://gerrit.cloudera.org:8080/#/c/22977/1/src/kudu/tablet/concurrent_btree.h@461
PS1, Line 461:   alignas(8) AtomicVersionValue versionPlaceholder_;
This actually has a measurable performance impact on was graviton and kills the 
whole purpose of the structure being packed.


http://gerrit.cloudera.org:8080/#/c/22977/1/src/kudu/tablet/concurrent_btree.h@1636
PS1, Line 1636: arch64__
              :     // Make sure the alignment is sufficient for the atomic 
version.
              :     constexpr size_t kMaxAlign = 
std::max(alignof(AtomicVersion),
              :                                           
alignof(LeafNode<Traits>));
              : #else
              :     constexpr size_t kMaxAlign = sizeof(AtomicVersion);
              : #endif
              :     void* m
On what platform is it not 8?
Also is this change enough to fix the issue or do you really need the 
alignas(8) above?



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Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I6f8ea46308f942ded97d93d27ae466fd13a31b53
Gerrit-Change-Number: 22977
Gerrit-PatchSet: 1
Gerrit-Owner: KeDeng <[email protected]>
Gerrit-Reviewer: KeDeng <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Marton Greber <[email protected]>
Gerrit-Reviewer: Zoltan Martonka <[email protected]>
Gerrit-Comment-Date: Wed, 04 Jun 2025 11:09:19 +0000
Gerrit-HasComments: Yes

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