On Fri, 23 Oct 2026 03:22:23 GMT, Ioi Lam <[email protected]> wrote: >> Before this PR, you cannot use -XX:AOTCache in the training run: >> >> >> $ java -XX:AOTCache=foo.aot -cp HelloWorld.jar \ >> -XX:AOTMode=record -XX:AOTConfiguration=hw.aotconfig \ >> HelloWorld >> [...] AOTCache must not be specified when using -XX:AOTMode=record >> >> >> However, in some cases, it may be desirable to train the AOT cache in two or >> more steps. For example: >> >> ## Separate Training for Framework and Application: >> >> - First perform a training run to exercise commonly-used areas of the >> framework. >> - Second, perform a training run of a specific application. >> >> The idea is that important parts of the framework may not be covered by a >> single application training run, but they may still be used in the >> production run due to runtime-specific input. >> >> >> # Train the framework >> java -XX:AOTCacheOutput=first.aot -cp FrameWork.jar FrameWorkTraningHelper >> >> # Train the app >> java -XX:AOTCache=first.aot -XX:AOTCacheOutput=second.aot -cp >> FrameWork.jar:App.jar MyApp >> >> # Production run using second.aot, which contains artifacts from >> # the first and second training runs >> java -XX:AOTCache=second.aot -cp FrameWork.jar:App.jar MyApp >> >> Note that the classpaths of the training runs must be compatible. I.e., the >> classpath of an earlier training run must be the same as, or the prefix of, >> the classpath of a later training run. >> >> ## Train the Same Application in Multiple Runs: >> >> An application may perform 3 different operations. It's not easy to perform >> all 3 operations in a single training run, as the 3 operations are >> represented by 3 separate main classes (`WalkDog`, `FeedCat`, and >> `WaterPlants`). So, we perform 3 separate training runs and combine the >> results into a single AOT cache. >> >> >> # Training >> java -XX:AOTCacheOutput=tmp1.aot -cp MyApp.jar WalkDog >> java -XX:AOTCache=tmp1.aot -XX:AOTCacheOutput=tmp2.aot -cp MyApp.jar FeedCat >> java -XX:AOTCache=tmp2.aot -XX:AOTCacheOutput=final.aot -cp MyApp.jar >> WaterPlants >> >> # Production: final.aot contains artifacts for optimizing all 3 operations: >> java -XX:AOTCache=final.aot -cp MyApp.jar WalkDog >> java -XX:AOTCache=final.aot -cp MyApp.jar FeedCat >> java -XX:AOTCache=final.aot -cp MyApp.jar WaterPlants >> >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Ioi Lam has updated the pull request with a new target base due to a merge or > a rebase. The pull request now contains 55 commits: > > - cleaned up comment > - Merge branch 'master' into aot-re-training > - @vnkozlov comments -- check AOTReplayTraining > - @vnkozlov comment -- removed unnecessary code > - Renamed the CDSAppTester workflows to AOT-Iterative1 and AOT-Iterative2 > - updated man page > - Merge branch 'master' into aot-re-training > - Avoid crashing inside ciRecords::Arguments<>::prepare() because > _first==nullptr > - Merge branch 'master' into aot-re-training > - Fixed bug found in AOT/JCK testing > - ... and 45 more: https://git.openjdk.org/jdk/compare/722e2fff...df2dd3ef
Marked as reviewed by iveresov (Reviewer). ------------- PR Review: https://git.openjdk.org/jdk/pull/31344#pullrequestreview-5623506060
