Messages in this thread | | | Date | Thu, 9 Nov 2023 12:05:27 -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 2023-11-09 11:45 a.m., Arnaldo Carvalho de Melo wrote: > 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?
Sure.
I also post the patch to https://lore.kernel.org/lkml/20231109164007.2037721-1-kan.liang@linux.intel.com/ Either folding it or using the new patch is fine for me.
BTW: the new perf test case for the feature is posted here. I think Ian is reviewing it. https://lore.kernel.org/lkml/20231107184020.1497571-1-kan.liang@linux.intel.com/
Thanks, Kan > > 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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