On Mon, 15 May 2023 19:59:13 GMT, Aleksey Shipilev <sh...@openjdk.org> wrote:
> One of our services has a hot path with AES/GCM cipher reuse. The JDK code > reinitializes the session key on that path, and > [JDK-8308105](https://bugs.openjdk.org/browse/JDK-8308105) shows up > prominently there. > > Fixing [JDK-8308105](https://bugs.openjdk.org/browse/JDK-8308105) would take > a while, as would likely require multiple patches in VM internals. Meanwhile, > we can avoid the multiarray allocations in AESCrypt.makeSessionKey > completely, reaping performance benefits. We can go even deeper: replace the > multi-array with the flat array and drop `expandToSubKey` completely. > > Example original profile is in the bug. > > There are other things we can polish in that code, but experiments show those > polishings have rather diminshed returns. > > On new benchmark: > > > Benchmark Mode Cnt Score Error Units > > ## Mac M1 > > # Before > AESReinit.test avgt 15 873,842 ± 6,911 ns/op > > # After > AESReinit.test avgt 15 347,632 ± 8,764 ns/op ; <--- 2.5x faster > > ## Xeon, c6.8xlarge > > # Before > AESReinit.test avgt 15 1524.307 ± 24.231 ns/op > > # After > AESReinit.test avgt 15 554.727 ± 12.876 ns/op ; <--- 2.75x faster > > ## Graviton, m6g.4xlarge > > # Before > AESReinit.test avgt 15 1913.492 ± 23.489 ns/op > > # After > AESReinit.test avgt 15 639.701 ± 5.033 ns/op ; <--- 2.99x faster > > > Additional testing: > - [x] Benchmarks > - [x] macos-aarch64-server-release, `jdk_security` > - [x] linux-x86_64-server-fastdebug, `tier1 tier2 tier3` This pull request has now been integrated. Changeset: 67657610 Author: Aleksey Shipilev <sh...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/6765761075361459f764f4f17a52ac6ecbe67f4e Stats: 133 lines in 2 files changed: 78 ins; 38 del; 17 mod 8308118: Avoid multiarray allocations in AESCrypt.makeSessionKey Reviewed-by: xuelei ------------- PR: https://git.openjdk.org/jdk/pull/13996
