RFR 8151163 All Buffer implementations should leverage Unsafe unaligned accessors

Aleksey Shipilev aleksey.shipilev at oracle.com
Thu Mar 10 17:14:57 UTC 2016

On 03/10/2016 08:06 PM, Paul Sandoz wrote:
>> On 8 Mar 2016, at 19:27, Paul Sandoz <Paul.Sandoz at oracle.com> wrote:
>>>> The changes in this webrev take advantage of those for JDK-8149469
>>>> and apply the unsafe double addressing scheme so certain byte buffer
>>>> view implementations can work across heap and direct buffers. This
>>>> should improve the performance on x86 for:
>>> I understand the idea, but I think we would need to verify this before
>>> pushing.
>> Admittedly i am leaning on the rational/motivation for the previous changes to use Unsafe unaligned accessors.
>> I less confident about the impact on non-x86 platforms.
>> I have some VarHandles related benchmark code [*] i can use to get some numbers.
> Here is some prelimiary perf numbers for x86 so far:
>   http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8151163-buffer-unsafe-unaligned-access/perf/ArrayViewTest.java

Okay, the performance data looks good. This addresses my concerns for
this issue, thanks!


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