Messages in this thread Patch in this message | | | Date | Thu, 9 Nov 2023 11:14:31 -0500 | Subject | Re: [PATCH V5 2/8] perf/x86: Add PERF_X86_EVENT_NEEDS_BRANCH_STACK flag | From | "Liang, Kan" <> |
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On 2023-11-08 4:31 p.m., Arnaldo Carvalho de Melo wrote: > Em Tue, Nov 07, 2023 at 12:11:50PM -0300, Arnaldo Carvalho de Melo escreveu: >> Em Mon, Nov 06, 2023 at 04:19:13PM -0500, Liang, Kan escreveu: >>> On 2023-11-06 4:12 p.m., Arnaldo Carvalho de Melo wrote: >>>> Em Wed, Oct 25, 2023 at 01:16:20PM -0700, kan.liang@linux.intel.com escreveu: >>> Ian has already reviewed the tool parts. > >>> But I still owe a test case for the feature. I will post a patch later. >>> https://lore.kernel.org/lkml/acbb895a-475e-4679-98fc-6b90c05a00af@linux.intel.com/ > >> I saw Ian's suggestion, and agree with it, we need to pair new features >> with regression tests in 'perf test', thanks for working on it! > > Kan, > > I still have to bisect, but can you check if this works for you?
The branch counters feature requires all the events to belong to a group. There is no problem for the normal perf usage which usually initializes an evlist even for a single evsel. But perf test is special, which may not initialize an evlist. The Sample parsing test case is one of the examples. It crashes with the !evsel->evlist.
The below change should fix it. I will post a complete patch shortly.
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 58a9b8c82790..7a6a2d1f96db 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2355,6 +2355,10 @@ static inline bool evsel__has_branch_counters(const struct evsel *evsel) { struct evsel *cur, *leader = evsel__leader(evsel);
+ /* The branch counters feature only supports group */ + if (!leader || !evsel->evlist) + return false; + evlist__for_each_entry(evsel->evlist, cur) { if ((leader == evsel__leader(cur)) && (cur->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS)) Thanks, Kan
> > > (gdb) run test -F -v 27 > Starting program: /root/bin/perf test -F -v 27 > > 27: Sample parsing : > --- start --- > > Program received signal SIGSEGV, Segmentation fault. > 0x00000000004e4aa6 in evsel.parse_sample () > Missing separate debuginfos, use: dnf debuginfo-install bzip2-libs-1.0.8-13.fc38.x86_64 cyrus-sasl-lib-2.1.28-9.fc38.x86_64 elfutils-debuginfod-client-0.189-3.fc38.x86_64 elfutils-libelf-0.189-3.fc38.x86_64 elfutils-libs-0.189-3.fc38.x86_64 glib2-2.76.5-2.fc38.x86_64 glibc-2.37-13.fc38.x86_64 keyutils-libs-1.6.1-6.fc38.x86_64 krb5-libs-1.21-3.fc38.x86_64 libbabeltrace-1.5.11-2.fc38.x86_64 libbrotli-1.0.9-11.fc38.x86_64 libcap-2.48-6.fc38.x86_64 libcom_err-1.46.5-4.fc38.x86_64 libcurl-8.0.1-5.fc38.x86_64 libevent-2.1.12-8.fc38.x86_64 libgcc-13.2.1-4.fc38.x86_64 libidn2-2.3.4-2.fc38.x86_64 libnghttp2-1.52.0-2.fc38.x86_64 libpfm-4.11.0-11.fc38.x86_64 libpsl-0.21.2-2.fc38.x86_64 libselinux-3.5-1.fc38.x86_64 libssh-0.10.5-1.fc38.x86_64 libstdc++-13.2.1-4.fc38.x86_64 libtraceevent-1.7.2-1.fc38.x86_64 libunistring1.0-1.0-1.fc38.x86_64 libunwind-1.6.2-7.fc38.x86_64 libuuid-2.38.1-4.fc38.x86_64 libxcrypt-4.4.36-1.fc38.x86_64 libzstd-1.5.5-1.fc38.x86_64 opencsd-1.3.3-1.fc38.x86_64 openldap-2.6.6-1.fc38.x86_64 openssl-libs-3.0.9-2.fc38.x86_64 perl-libs-5.36.1-497.fc38.x86_64 popt-1.19-2.fc38.x86_64 python3-libs-3.11.6-1.fc38.x86_64 slang-2.3.3-3.fc38.x86_64 zlib-1.2.13-3.fc38.x86_64 > (gdb) bt > #0 0x00000000004e4aa6 in evsel.parse_sample () > #1 0x00000000004b28dc in do_test () > #2 0x00000000004b2acd in test.sample_parsing () > #3 0x0000000000495348 in test_and_print.isra () > #4 0x0000000000495f5d in cmd_test () > #5 0x00000000004c2a29 in run_builtin () > #6 0x000000000041053f in main () > (gdb) >
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