Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Ian Rogers <> | Date | Tue, 9 Apr 2024 08:46:31 -0700 | Subject | Re: BISECTED: perf test 'Miscellaneous Intel PT' failing on Intel hybrid machines |
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On Tue, Apr 9, 2024 at 8:34 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > On Tue, Apr 09, 2024 at 12:32:06PM -0300, Arnaldo Carvalho de Melo wrote: > > root@x1:~# perf test "Miscellaneous Intel PT testing" > > 112: Miscellaneous Intel PT testing : FAILED! > > root@x1:~# > > > > then I revert: > > > > commit 642e1ac96aaa12aeb41402e68eac7faf5917a67a (HEAD -> perf-tools-next) > > Author: Arnaldo Carvalho de Melo <acme@redhat.com> > > Date: Tue Apr 9 12:28:49 2024 -0300 > > > > Revert "perf pmus: Check if we can encode the PMU number in perf_event_attr.type" > > > > This reverts commit 82fe2e45cdb00de4fa648050ae33bdadf9b3294a. > > ⬢[acme@toolbox perf-tools-next]$ > > > > It works now: > > > > root@x1:~# perf -v > > perf version 6.8.g642e1ac96aaa > > root@x1:~# perf test "Miscellaneous Intel PT testing" > > 117: Miscellaneous Intel PT testing : Ok > > root@x1:~# > > > > Investigating, if you come up with ideas, lemme know. > > Some more context: > > When this patch was implemented/tested I had access only to an ARM64 > hybrid machine, now my notebook is a Rocket Lake lenovo (13th gen), that > is hybrid and the test is failing with: > > root@x1:~# perf test -v "Miscellaneous Intel PT testing" > 112: Miscellaneous Intel PT testing : > --- start --- > test child forked, pid 304355 > --- Test system-wide sideband --- > Checking for CPU-wide recording on CPU 0 > OK > Checking for CPU-wide recording on CPU 1 > OK > Linux > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 1.934 MB /tmp/perf-test-intel-pt-sh.xACV6V7Hn4/test-perf.data ] > OK > --- Test per-thread recording --- > Workload PIDs are 304377 and 304378 > perf PID is 304389 > Waiting for "perf record has started" message > OK > pid 0 cpu -1 fd 5 : sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 5 > pid 0 cpu -1 fd 6 : sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 6 > pid 304377 cpu -1 fd 7 : sys_perf_event_open: pid 304377 cpu -1 group_fd -1 flags 0x8 = 7 > pid 304380 cpu -1 fd 8 : sys_perf_event_open: pid 304380 cpu -1 group_fd -1 flags 0x8 = 8 > pid 304378 cpu -1 fd 9 : sys_perf_event_open: pid 304378 cpu -1 group_fd -1 flags 0x8 = 9 > pid 304381 cpu -1 fd 10 : sys_perf_event_open: pid 304381 cpu -1 group_fd -1 flags 0x8 = 10 > pid 304377 cpu -1 fd 11 : sys_perf_event_open: pid 304377 cpu -1 group_fd -1 flags 0x8 = 11 > pid 304380 cpu -1 fd 12 : sys_perf_event_open: pid 304380 cpu -1 group_fd -1 flags 0x8 = 12 > pid 304378 cpu -1 fd 13 : sys_perf_event_open: pid 304378 cpu -1 group_fd -1 flags 0x8 = 13 > pid 304381 cpu -1 fd 14 : sys_perf_event_open: pid 304381 cpu -1 group_fd -1 flags 0x8 = 14 > fd 7 : idx 0: mmapping fd 7 > fd 11 fd_to 7 : idx 0: set output fd 11 -> 7 > fd 8 : idx 1: mmapping fd 8 > fd 12 fd_to 8 : idx 1: set output fd 12 -> 8 > fd 9 : idx 2: mmapping fd 9 > fd 13 fd_to 9 : idx 2: set output fd 13 -> 9 > fd 10 : idx 3: mmapping fd 10 > fd 14 fd_to 10 : idx 3: set output fd 14 -> 10 > Checking 10 fds > No mmap for fd 5
Thanks Arnaldo, so the reverted change is: ``` --- a/tools/perf/util/pmus.c +++ b/tools/perf/util/pmus.c @@ -4,6 +4,7 @@ #include <subcmd/pager.h> #include <sys/types.h> #include <dirent.h> +#include <pthread.h> #include <string.h> #include <unistd.h> #include "debug.h" @@ -492,9 +493,35 @@ int perf_pmus__num_core_pmus(void) return count; }
+static bool __perf_pmus__supports_extended_type(void) +{ + struct perf_pmu *pmu = NULL; + + if (perf_pmus__num_core_pmus() <= 1) + return false; + + while ((pmu = perf_pmus__scan_core(pmu)) != NULL) { + if (!is_event_supported(PERF_TYPE_HARDWARE, PERF_COUNT_HW_CPU_CYCLES | ((__u64)pmu-> type << PERF_PMU_TYPE_SHIFT))) + return false; + } + + return true; +} + +static bool perf_pmus__do_support_extended_type; + +static void perf_pmus__init_supports_extended_type(void) +{ + perf_pmus__do_support_extended_type = __perf_pmus__supports_extended_type(); +} + bool perf_pmus__supports_extended_type(void) { - return perf_pmus__num_core_pmus() > 1; + static pthread_once_t extended_type_once = PTHREAD_ONCE_INIT; + + pthread_once(&extended_type_once, perf_pmus__init_supports_extended_type); + + return perf_pmus__do_support_extended_type; }
struct perf_pmu *evsel__find_pmu(const struct evsel *evsel) ``` On your Intel this should have previously returned true as "perf_pmus__num_core_pmus() > 1", and with the new code presumably is_event_supported is returning false. Could you dump the PMU's name at that point? Is cpu_core or cpu_atom looking like it doesn't support the event? Is the test failing when run as root (ie is is_event_supported failing to have expected fallback paths)?
Thanks, Ian
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