5.15-stable review patch. If anyone has any objections, please let me know.
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From: Arnaldo Carvalho de Melo acme@redhat.com
[ Upstream commit 4fce4b91fd1aabb326c46e237eb4b19ab72598f8 ]
While working on 'perf version --build-options' I noticed that:
$ perf version --build-options perf version 6.15.rc1.g312a07a00d31 aio: [ on ] # HAVE_AIO_SUPPORT bpf: [ on ] # HAVE_LIBBPF_SUPPORT bpf_skeletons: [ on ] # HAVE_BPF_SKEL debuginfod: [ OFF ] # HAVE_DEBUGINFOD_SUPPORT <SNIP>
And looking at tools/perf/Makefile.config I also noticed that it is not opt-in, meaning we will attempt to build with it in all normal cases.
So add the usual warning at build time to let the user know that something recommended is missing, now we see:
Makefile.config:563: No elfutils/debuginfod.h found, no debuginfo server support, please install elfutils-debuginfod-client-devel or equivalent
And after following the recommendation:
$ perf check feature debuginfod debuginfod: [ on ] # HAVE_DEBUGINFOD_SUPPORT $ ldd ~/bin/perf | grep debuginfo libdebuginfod.so.1 => /lib64/libdebuginfod.so.1 (0x00007fee5cf5f000) $
With this feature on several perf tools will fetch what is needed and not require all the contents of the debuginfo packages, for instance:
# rpm -qa | grep kernel-debuginfo # pahole --running_kernel_vmlinux pahole: couldn't find a vmlinux that matches the running kernel HINT: Maybe you're inside a container or missing a debuginfo package? # # perf trace -e open* perf probe --vars icmp_rcv 0.000 ( 0.005 ms): perf/97391 openat(dfd: CWD, filename: "/etc/ld.so.cache", flags: RDONLY|CLOEXEC) = 3 0.014 ( 0.004 ms): perf/97391 openat(dfd: CWD, filename: "/lib64/libm.so.6", flags: RDONLY|CLOEXEC) = 3 <SNIP> 32130.100 ( 0.008 ms): perf/97391 openat(dfd: CWD, filename: "/root/.cache/debuginfod_client/aa3c82b4a13f9c0e0301bebb20fe958c4db6f362/debuginfo") = 3 <SNIP> Available variables at icmp_rcv @<icmp_rcv+0> struct sk_buff* skb <SNIP> # # pahole --running_kernel_vmlinux /root/.cache/debuginfod_client/aa3c82b4a13f9c0e0301bebb20fe958c4db6f362/debuginfo # file /root/.cache/debuginfod_client/aa3c82b4a13f9c0e0301bebb20fe958c4db6f362/debuginfo /root/.cache/debuginfod_client/aa3c82b4a13f9c0e0301bebb20fe958c4db6f362/debuginfo: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, BuildID[sha1]=aa3c82b4a13f9c0e0301bebb20fe958c4db6f362, with debug_info, not stripped # ls -la /root/.cache/debuginfod_client/aa3c82b4a13f9c0e0301bebb20fe958c4db6f362/debuginfo -r--------. 1 root root 475401512 Mar 27 21:00 /root/.cache/debuginfod_client/aa3c82b4a13f9c0e0301bebb20fe958c4db6f362/debuginfo #
Then, cached:
# perf stat --null perf probe --vars icmp_rcv Available variables at icmp_rcv @<icmp_rcv+0> struct sk_buff* skb
Performance counter stats for 'perf probe --vars icmp_rcv':
0.671389041 seconds time elapsed
0.519176000 seconds user 0.150860000 seconds sys
Fixes: c7a14fdcb3fa7736 ("perf build-ids: Fall back to debuginfod query if debuginfo not found") Tested-by: Ingo Molnar mingo@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Dmitriy Vyukov dvyukov@google.com Cc: Howard Chu howardchu95@gmail.com Cc: Ian Rogers irogers@google.com Cc: Jiri Olsa jolsa@kernel.org Cc: Kan Liang kan.liang@linux.intel.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Frank Ch. Eigler fche@redhat.com Link: https://lore.kernel.org/r/Z_dkNDj9EPFwPqq1@gmail.com [ Folded patch from Ingo to have the debian/ubuntu devel package added build warning message ] Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/Makefile.config | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 973c0d5ed8d8b..90cbbe2e90f9b 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -538,6 +538,8 @@ ifndef NO_LIBELF ifeq ($(feature-libdebuginfod), 1) CFLAGS += -DHAVE_DEBUGINFOD_SUPPORT EXTLIBS += -ldebuginfod + else + $(warning No elfutils/debuginfod.h found, no debuginfo server support, please install libdebuginfod-dev/elfutils-debuginfod-client-devel or equivalent) endif endif