Messages in this thread | | | Date | Thu, 9 Nov 2023 13:45:49 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH V5 2/8] perf/x86: Add PERF_X86_EVENT_NEEDS_BRANCH_STACK flag |
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Em Thu, Nov 09, 2023 at 11:14:31AM -0500, Liang, Kan escreveu: > > > 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.
Thanks for the quick response, if all that is needed are the checks below, I'll fold it into your original patch:
2ae01908298426e4 perf tools: Add branch counter knob
So that we don't regress, ok?
I'll add a note and the Link tag points to this discussion in case people want to do historical digs in the future :-)
- Arnaldo
> 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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- Arnaldo
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