From 83868bf71d2eb7700b37f1ea188007f0125e4ee4 Mon Sep 17 00:00:00 2001 From: Thomas Richter Date: Tue, 31 Jul 2018 09:32:54 +0200 Subject: [PATCH] perf build: Fix installation directory for eBPF The perf tool build and install is controlled via a Makefile. The 'install' rule creates directories and copies files. Among them are header files installed in /usr/lib/include/perf/bpf/. However all listed examples are installing its header files in /usr/lib//...[/include]/header.h and not in /usr/lib/include//.../header.h. Background information: Building the Fedora 28 glibc RPM on s390x and s390 fails on s390 (gcc -m31) as gcc is not able to find header-files like stdbool.h. In the glibc.spec file, you can see that glibc is configured with "--with-headers". In this case, first -nostdinc is added to the CFLAGS and then further include paths are added via -isystem. One of those paths should contain header files like stdbool.h. In order to get this path, gcc is invoked with: - on Fedora 28 (with 4.18 kernel): $ gcc -print-file-name=include /usr/lib/gcc/s390x-redhat-linux/8/include $ gcc -m31 -print-file-name=include /usr/lib/gcc/s390x-redhat-linux/8/../../../../lib/include => If perf is installed, this is: /usr/lib/include On my machine this directory is only containing the directory "perf". If perf is not installed gcc returns: /usr/lib/gcc/s390x-redhat-linux/8/include - on Ubuntu 18.04 (with 4.15 kernel): $ gcc -print-file-name=include /usr/lib/gcc/s390x-linux-gnu/7/include $ gcc -m31 -print-file-name=include /usr/lib/gcc/s390x-linux-gnu/7/include => gcc returns the correct path even if perf is installed. In each case, the introduction of the subdirectory /usr/lib/include leads to the regression that one can not build the glibc RPM for s390 anymore as gcc can not find headers like stdbool.h. To remedy this install bpf.h to /usr/lib/perf/include/bpf/bpf.h Output before using the command 'perf test -Fv 40': echo '...[bpf-program-source]...' | /usr/bin/clang ... \ -I/root/lib/include/perf/bpf ... ^^^^^^^^^^^^ ... [root@p23lp27 perf]# perf test -F 40 40: BPF filter : 40.1: Basic BPF filtering : Ok 40.2: BPF pinning : Ok 40.3: BPF prologue generation : Ok 40.4: BPF relocation checker : Ok [root@p23lp27 perf]# Output after using command 'perf test -Fv 40': echo '...[bpf-program-source]...' | /usr/bin/clang ... \ -I/root/lib/perf/include/bpf ... ^^^^^^^^^^^^ ... [root@p23lp27 perf]# perf test -F 40 40: BPF filter : 40.1: Basic BPF filtering : Ok 40.2: BPF pinning : Ok 40.3: BPF prologue generation : Ok 40.4: BPF relocation checker : Ok [root@p23lp27 perf]# Committer testing: While the above 'perf test -F 40' (or 'perf test bpf') will allow us to see that the correct path is now added via -I, to actually test this we better try to use a bpf script that includes files in the changed directory. We have the files that now reside in /root/lib/perf/examples/bpf/ to do just that: # tail -8 /root/lib/perf/examples/bpf/5sec.c #include int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec) { return sec == 5; } license(GPL); # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 4 0.333 (4000.086 ms): sleep/9248 nanosleep(rqtp: 0x7ffc155f3300) = 0 # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 5 0.287 ( ): sleep/9659 nanosleep(rqtp: 0x7ffeafe38200) ... 0.290 ( ): perf_bpf_probe:hrtimer_nanosleep:(ffffffff9911efe0) tv_sec=5 0.287 (5000.059 ms): sleep/9659 ... [continued]: nanosleep()) = 0 # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 6 0.247 (5999.951 ms): sleep/10068 nanosleep(rqtp: 0x7fff2086d900) = 0 # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 5.987 0.293 ( ): sleep/10489 nanosleep(rqtp: 0x7ffdd4fc10e0) ... 0.296 ( ): perf_bpf_probe:hrtimer_nanosleep:(ffffffff9911efe0) tv_sec=5 0.293 (5986.912 ms): sleep/10489 ... [continued]: nanosleep()) = 0 # Suggested-by: Stefan Liebler Suggested-by: Arnaldo Carvalho de Melo Signed-off-by: Thomas Richter Reviewed-by: Hendrik Brueckner Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Martin Schwidefsky Fixes: 1b16fffa389d ("perf llvm-utils: Add bpf include path to clang command line") Link: http://lkml.kernel.org/r/20180731073254.91090-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Makefile.config | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index d3318f99006c..f6d1a03c7523 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -907,8 +907,8 @@ bindir = $(abspath $(prefix)/$(bindir_relative)) mandir = share/man infodir = share/info perfexecdir = libexec/perf-core -perf_include_dir = lib/include/perf -perf_examples_dir = lib/examples/perf +perf_include_dir = lib/perf/include +perf_examples_dir = lib/perf/examples sharedir = $(prefix)/share template_dir = share/perf-core/templates STRACE_GROUPS_DIR = share/perf-core/strace/groups -- 2.30.2