RFR: 8331185: Enable compiler memory limits in debug builds

Vladimir Kozlov kvn at openjdk.org
Fri Apr 26 18:34:52 UTC 2024


On Fri, 26 Apr 2024 10:04:28 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> See [1] for previous discussions.
> 
> We'd like to introduce a default memory limit for compilations in debug builds. That way, we can catch pathological compiler errors that have an unreasonably high per-compilation memory footprint early during testing.
> 
> The default limit affects all compilations, unless the method is subject to a memory limit set from command line. Meaning, `-XX:CompileCommand=MemLimit,...` overrules the default.
> 
> Examples:
> 
> This lowers the memlimit for j.l.String methods - all methods will have the default 1GB limit in a debug JVM. Only j.l.String will run with a 100M limit: `-XX:CompileCommand=MemLimit,java.lang.String::*,100m`
> 
> This disables the default memlimit globally: `-XX:CompileCommand=MemLimit,*.*,0`
> 
> 
> ---
> 
> The patch:
> 
> 1) adds a debug-only default memory limit of **1GB** (as proposed by @vnkozlov). The limit action is "crash", meaning we will assert.
> 2) To test the mechanics, we now print out the memory limit for each compilation in the compilation cost record.
> 3) Adapted and extended tests
> 
> I also fixed up some copyrights that I overlooked last year when adding the compiler memory statistics this patch builds atop of.
> 
> 
> Tested:
> 
> - manually on Mac m1 (debug and release)
> - GHAs are running
> - but Oracle will do more testing before this goes in
> 
> [1] https://mail.openjdk.org/pipermail/hotspot-compiler-dev/2024-April/074787.html

test/hotspot/jtreg/compiler/print/CompileCommandPrintMemStat.java line 3:

> 1: /*
> 2:  * Copyright (c) 2023, 2024 Red Hat, Inc. All rights reserved.
> 3:  * Copyright (c) 2023, 2024 Oracle and/or its affiliates. All rights reserved.

Missing comma `,` after second year. Files header verifier failed for both test files.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18969#discussion_r1581394676


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