On Fri, 20 Dec 2024 07:53:07 GMT, Matthias Baesken <mbaes...@openjdk.org> wrote:
>> Please review this fairly simple change to improve how the >> `JimageDiffGenerator` works. The original implementation is pretty naive and >> read all bytes into memory and then compared them. This improved version >> only reads bytes on a bound buffer into memory compares those bytes and if >> equal continues on to reading the next bytes (`2k` at most) at a time. >> Previously it was `2*N` (where `N` is the file size of a file in bytes) part >> of the JDK. Ouch. >> >> There is still the off-chance of reading a full file into memory when the >> generator detects a change, but this shouldn't happen for large files since >> the total diff should be around `600K` as of today. >> >> This also reverts changes from >> [JDK-8344036](https://bugs.openjdk.org/browse/JDK-8344036) other than the >> `/timeout` change to the test, which is preserved as I think this bump is no >> longer needed. >> >> Testing: >> - [x] GHA >> - [x] jlink tests on a fastdebug build with >> `--with-native-debug-symbols=internal` (so as to have a large libjvm.so). >> - [x] Manual reproducer from the bug which fails with OOM before the patch >> and passes after >> >> Thoughts? > > Hi Severin, I added it to our build/test queue. Thanks for the review @MBaesken! ------------- PR Comment: https://git.openjdk.org/jdk/pull/22835#issuecomment-2574957834
