Messages in this thread | | | Date | Tue, 10 Nov 2015 16:26:02 -0800 | From | "Shi, Yang" <> | Subject | Re: [PATCH 2/2] arm64: bpf: add BPF XADD instruction |
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On 11/10/2015 4:08 PM, Eric Dumazet wrote: > On Tue, 2015-11-10 at 14:41 -0800, Yang Shi wrote: >> aarch64 doesn't have native support for XADD instruction, implement it by >> the below instruction sequence: >> >> Load (dst + off) to a register >> Add src to it >> Store it back to (dst + off) > > Not really what is needed ? > > See this BPF_XADD as an atomic_add() equivalent.
I see. Thanks. The documentation doesn't say too much about "exclusive" add. If so it should need load-acquire/store-release.
I will rework it.
Yang
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