Re: [PATCH] perf build: Fix detection of latest openjdk

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Tue, Apr 07, 2026 at 01:03:20AM -0700, Namhyung Kim wrote:
> My fedora system fails to find openjdk even if I installed the
> 'java-latest-openjdk-devel' package as in the warning message.
> It turns out that the directory path is different than what's in the
> output of alternatives.
> 
>   Makefile.config:1122: No openjdk development package found, please install JDK package,
>                         e.g. openjdk-8-jdk, java-latest-openjdk-devel
> 
> The Makefile.config has the rule like below to detect the installed
> directory with a version number.
> 
>   $ alternatives --display java | tail -1 | cut -d ' ' -f 5 | sed -e 's%/jre/bin/java.%%g' -e 's%/bin/java.%%g'
>   /usr/lib/jvm/java-21-openjdk
> 
> This is to find a directory where the header file (jvmti.h) is like
> /usr/lib/jvm/java-21-openjdk/include/jvmti.h.  However the header file
> was in a different directory.
> 
>   $ rpm -ql java-latest-openjdk-devel | grep jvmti.h
>   /usr/lib/jvm/java-latest-openjdk/include/jvmti.h
> 
> It seems the directory name is fixed to provide the latest version.
> Let's check the directory name before using the parsed name.  With this
> change, the warning is gone on my system.

Interesting, I'm not noticing this on Fedora rawhide (44), I created a
fresh toolbox container with fedora:rawhide and had, as you, this:

⬢ [acme@toolbx perf-tools-next]$ m
make: Entering directory '/home/acme/git/linux/tools/perf'
  BUILD:   Doing 'make -j32' parallel build
Warning: Kernel ABI header differences:
  diff -u tools/arch/x86/include/uapi/asm/svm.h arch/x86/include/uapi/asm/svm.h
Makefile.config:1070: No libbabeltrace found, disables 'perf data' CTF format support, please install libbabeltrace-dev[el]/libbabeltrace-ctf-dev
Makefile.config:1122: No openjdk development package found, please install JDK package, e.g. openjdk-8-jdk, java-latest-openjdk-devel


Then I just followed the suggestion and did a:

$ sudo dnf install java-latest-openjdk-devel

And after that the 1122 warning vanished and:

⬢ [acme@toolbx perf-tools-next]$ ls -la /tmp/build/perf-tools-next/feature/test-jvmti*
-rwxr-xr-x. 1 acme acme 12384 Apr  7 09:14 /tmp/build/perf-tools-next/feature/test-jvmti.bin
-rwxr-xr-x. 1 acme acme 12392 Apr  7 09:14 /tmp/build/perf-tools-next/feature/test-jvmti-cmlr.bin
-rw-r--r--. 1 acme acme  1188 Apr  7 09:14 /tmp/build/perf-tools-next/feature/test-jvmti-cmlr.d
-rw-r--r--. 1 acme acme     0 Apr  7 09:14 /tmp/build/perf-tools-next/feature/test-jvmti-cmlr.make.output
-rw-r--r--. 1 acme acme  1122 Apr  7 09:14 /tmp/build/perf-tools-next/feature/test-jvmti.d
-rw-r--r--. 1 acme acme     0 Apr  7 09:14 /tmp/build/perf-tools-next/feature/test-jvmti.make.output
⬢ [acme@toolbx perf-tools-next]$ cat /tmp/build/perf-tools-next/feature/test-jvmti.make.output
⬢ [acme@toolbx perf-tools-next]$

⬢ [acme@toolbx perf-tools-next]$ alternatives --display java | tail -1 | cut -d ' ' -f 5 | sed -e 's%/jre/bin/java.%%g' -e 's%/bin/java.%%g'
/usr/lib/jvm/java-latest-openjdk
⬢ [acme@toolbx perf-tools-next]$

⬢ [acme@toolbx perf-tools-next]$ alternatives --display java
java - status is auto.
 link currently points to /usr/lib/jvm/java-latest-openjdk/bin/java
/usr/lib/jvm/java-latest-openjdk/bin/java - priority 1
 follower jre: /usr/lib/jvm/java-latest-openjdk
 follower alt-java: /usr/lib/jvm/java-latest-openjdk/bin/alt-java
 follower jcmd: /usr/lib/jvm/java-latest-openjdk/bin/jcmd
 follower keytool: /usr/lib/jvm/java-latest-openjdk/bin/keytool
 follower rmiregistry: /usr/lib/jvm/java-latest-openjdk/bin/rmiregistry
 follower java.1.gz: /usr/lib/jvm/java-latest-openjdk/man/man1/java.1
 follower alt-java.1.gz: /usr/lib/jvm/java-latest-openjdk/man/man1/alt-java.1
 follower jcmd.1.gz: /usr/lib/jvm/java-latest-openjdk/man/man1/jcmd.1
 follower keytool.1.gz: /usr/lib/jvm/java-latest-openjdk/man/man1/keytool.1
 follower rmiregistry.1.gz: /usr/lib/jvm/java-latest-openjdk/man/man1/rmiregistry.1
Current `best' version is /usr/lib/jvm/java-latest-openjdk/bin/java.
⬢ [acme@toolbx perf-tools-next]$

- Arnaldo
 
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/Makefile.config | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 333ddd0e4bd814e9..e6686641761fd0bf 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -1096,8 +1096,12 @@ ifndef NO_JVMTI
>    ifneq (,$(wildcard /usr/sbin/update-java-alternatives))
>      JDIR=$(shell /usr/sbin/update-java-alternatives -l | head -1 | awk '{print $$3}')
>    else
> -    ifneq (,$(wildcard /usr/sbin/alternatives))
> -      JDIR=$(shell /usr/sbin/alternatives --display java | tail -1 | cut -d' ' -f 5 | sed -e 's%/jre/bin/java.%%g' -e 's%/bin/java.%%g')
> +    ifneq (,$(wildcard /usr/lib/jvm/java-latest-openjdk/include))
> +      JDIR=/usr/lib/jvm/java-latest-openjdk
> +    else
> +      ifneq (,$(wildcard /usr/sbin/alternatives))
> +        JDIR=$(shell /usr/sbin/alternatives --display java | tail -1 | cut -d' ' -f 5 | sed -e 's%/jre/bin/java.%%g' -e 's%/bin/java.%%g')
> +      endif
>      endif
>    endif
>    ifndef JDIR
> -- 
> 2.53.0