On Fri, 4 Nov 2022 14:35:00 GMT, Thomas Stuefe <stu...@openjdk.org> wrote:
> This patch adds NMT tracking to the zlib. > > *Please note: we currently discuss whether NMT can be expanded across the JDK > in this ML discussion [1]. This PR depends on the outcome of that discussion > and won't proceed unless greenlighted. But since [1] is stalled, I post the > PR for RFR to get some feedback on the code itself and for people to try it > out.* > > NMT tracks hotspot native allocations but does not cover the JDK (apart from > small exceptions). But the native memory > footprint of JDK libraries can be very significant. Recently we had a > customer whose zlib footprint went into the ~40GB range. We analyzed the > problem with an in-house memory tracker, but things would have been a lot > simpler using NMT. > > This patch instruments the zlib via zalloc hooks, which is minimally > invasive. It does not touch zlib sources, so it works with both the bundled > zlib and system zlib. All the instrumentation happens in the JVM zlib wrapper. > > > - j.u.zip (deflate) (reserved=624, committed=624) > (malloc=624 #3) > > - j.u.zip (inflate) (reserved=221377904, committed=221377904) > (malloc=221377904 #60877) > > - Zip (other) (reserved=8163446896, committed=8163446896) > (malloc=8163446896 #182622) > > > [1] https://mail.openjdk.org/pipermail/core-libs-dev/2022-November/096197.html Withdrawing for now; let's see how our discussion goes. ------------- PR: https://git.openjdk.org/jdk/pull/10988
