On Mon, 25 Jan 2021 19:38:16 GMT, Anton Kozlov <akoz...@openjdk.org> wrote:
>> Please review the implementation of JEP 391: macOS/AArch64 Port. >> >> It's heavily based on existing ports to linux/aarch64, macos/x86_64, and >> windows/aarch64. >> >> Major changes are in: >> * src/hotspot/cpu/aarch64: support of the new calling convention (subtasks >> JDK-8253817, JDK-8253818) >> * src/hotspot/os_cpu/bsd_aarch64: copy of os_cpu/linux_aarch64 with >> necessary adjustments (JDK-8253819) >> * src/hotspot/share, test/hotspot/gtest: support of write-xor-execute (W^X), >> required on macOS/AArch64 platform. It's implemented with >> pthread_jit_write_protect_np provided by Apple. The W^X mode is local to a >> thread, so W^X mode change relates to the java thread state change (for java >> threads). In most cases, JVM executes in write-only mode, except when >> calling a generated stub like SafeFetch, which requires a temporary switch >> to execute-only mode. The same execute-only mode is enabled when a java >> thread executes in java or native states. This approach of managing W^X mode >> turned out to be simple and efficient enough. >> * src/jdk.hotspot.agent: serviceability agent implementation (JDK-8254941) > > Anton Kozlov has updated the pull request incrementally with two additional > commits since the last revision: > > - Refactor CDS disabling > - Redo builsys support for aarch64-darwin I looked through the SA changes. Overall looks good except for a couple of minor issues noted. For the most part it seems to have been boilerplate copy-n-paste from existing ports. If there is anything you want me to take a closer look at, let me know. src/jdk.hotspot.agent/macosx/native/libsaproc/MacosxDebuggerLocal.m line 702: > 700: primitiveArray = (*env)->GetLongArrayElements(env, registerArray, > NULL); > 701: > 702: #undef REG_INDEX I'm not so sure why the #undef and subsequent #define of REG_INDEX is needed since it seems to just get #define'd back to the same value. src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/bsd/aarch64/BsdAARCH64ThreadContext.java line 2: > 1: /* > 2: * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved. Update copyright. ------------- Marked as reviewed by cjplummer (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/2200
