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

[Namhyung Kim <namhyung@kernel.org>]

On Tue, Apr 07, 2026 at 09:19:57AM -0300, Arnaldo Carvalho de Melo wrote:
> 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]$

Thanks for checking this.  Looks like a local issue on my system.
I've updated the alternatives to point to the latest version.

Thanks,
Namhyung