On Thu, 5 Sep 2024 18:02:32 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org>
wrote:
>> Per Minborg has updated the pull request incrementally with one additional
>> commit since the last revision:
>>
>> Fix errors in a benchmark
>
> src/java.base/share/classes/jdk/internal/foreign/SegmentBulkOperations.java
> line 76:
>
>> 74: final int limit = (int) (dst.length & (NATIVE_THRESHOLD_FILL
>> - 8));
>> 75: for (; offset < limit; offset += 8) {
>> 76: SCOPED_MEMORY_ACCESS.putLong(dst.sessionImpl(),
>> dst.unsafeGetBase(), dst.unsafeGetOffset() + offset, longValue);
>
> Now that I look again at this - I think all these calls should use
> `putXYZUnaligned`. Otherwise alignment can introduce issues on some
> platforms. That will call an `Unsafe` intrinsics that will do the best
> possible job at serving a potentially unaligned request. This is, btw, what
> we use when we do e.g. `segment.get(JAVA_LONG, offset)`. Since you are using
> a lower-level API here, you need to make sure you use the correct memory
> access primitive.
This tactic should be reflected in a top-level comment in this class.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/20848#discussion_r1745966605
