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
-------------
Commit messages:
- JDK-8296360-Track-native-memory-used-by-zlib-via-NMT
Changes: https://git.openjdk.org/jdk/pull/10988/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10988&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8296360
Stats: 192 lines in 9 files changed: 179 ins; 1 del; 12 mod
Patch: https://git.openjdk.org/jdk/pull/10988.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/10988/head:pull/10988
PR: https://git.openjdk.org/jdk/pull/10988
