[riscv-port] Integrated: 8277890: riscv: fix the infinite LR/SC loop in BarrierSetAssembler::eden_allocate
yadongwang at openjdk.java.net
Tue Nov 30 03:33:34 UTC 2021
On Mon, 29 Nov 2021 15:06:51 GMT, Yadong Wang <yadongwang at openjdk.org> wrote:
> This bug can be reproduced by `java -XX:+UseSerialGC -XX:-UseTLAB -XX:TieredStopAtLevel=1 -version` on the unmatched board where this command will hang. The reason is that the implementation of load reserved/store conditional loop in BarrierSetAssembler::eden_allocate breaks the RISC-V Atomic extension spec:
> For the
> sequence to be guaranteed to eventually succeed, the dynamic code executed between the LR and
> SC instructions can only contain other instructions from the base \I" subset, excluding loads, stores,
> backward jumps or taken backward branches, FENCE, FENCE.I, and SYSTEM instructions.
> It may cause an unspecified behaviour depends on specific hardware implementations.
This pull request has now been integrated.
Author: Yadong Wang <yadongwang at openjdk.org>
Committer: Fei Yang <fyang at openjdk.org>
Stats: 24 lines in 1 file changed: 12 ins; 8 del; 4 mod
8277890: riscv: fix the infinite LR/SC loop in BarrierSetAssembler::eden_allocate
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