Zoltan Martonka has posted comments on this change. ( http://gerrit.cloudera.org:8080/21127 )
Change subject: [ARM] Concurrent binary tree memory barriers fixed. ...................................................................... Patch Set 6: (1 comment) http://gerrit.cloudera.org:8080/#/c/21127/6/src/kudu/tablet/concurrent_btree.h File src/kudu/tablet/concurrent_btree.h: http://gerrit.cloudera.org:8080/#/c/21127/6/src/kudu/tablet/concurrent_btree.h@390 PS6, Line 390: AtomicVersionValue VersionAcqRel() { : return version_.load(std::memory_order_acq_rel); : } > I'm curios how this make sense if by the specification the behavior of std: No, I missed it. There is actually no right flag for what we wan't to do here. We need to use std::atomic_thread_fence(std::memory_order_acquire); (because it is 2-way). To my best knowledge, g++ compiled the undefined behaviour as seq_cst, so it worked, but also slowed down the execution. -- To view, visit http://gerrit.cloudera.org:8080/21127 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ie7c02dc3b9444599ef680fa9b29ae7a4d39dd382 Gerrit-Change-Number: 21127 Gerrit-PatchSet: 6 Gerrit-Owner: Zoltan Martonka <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Anonymous Coward (763) Gerrit-Reviewer: Ashwani Raina <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Tidy Bot (241) Gerrit-Reviewer: Zoltan Chovan <[email protected]> Gerrit-Reviewer: Zoltan Martonka <[email protected]> Gerrit-Comment-Date: Tue, 23 Apr 2024 12:57:02 +0000 Gerrit-HasComments: Yes
