kernel.git/tools/perf/util/evsel.c, branch linux-4.18.y

perf evsel: Store ids for events with their own cpus perf_event__synthesize_event_update_cpus

2018-11-13T19:12:17Z

[ Upstream commit 4ab8455f8bd83298bf7f67ab9357e3b1cc765c7d ] John reported crash when recording on an event under PMU with cpumask defined: root@localhost:~# ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1 perf: Segmentation fault Obtained 9 stack frames. ./perf_debug_() [0x4c5ef8] [0xffff82ba267c] ./perf_debug_() [0x4bc5a8] ./perf_debug_() [0x419550] ./perf_debug_() [0x41a928] ./perf_debug_() [0x472f58] ./perf_debug_() [0x473210] ./perf_debug_() [0x4070f4] /lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe0) [0xffff8294c8a0] Segmentation fault (core dumped) We synthesize an update event that needs to touch the evsel id array, which is not defined at that time. Fixing this by forcing the id allocation for events with their own cpus. Reported-by: John Garry Signed-off-by: Jiri Olsa Tested-by: John Garry Cc: Alexander Shishkin Cc: Andi Kleen Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linuxarm@huawei.com Fixes: bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update") Link: http://lkml.kernel.org/r/20181003212052.GA32371@krava Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf evsel: Fix potential null pointer dereference in perf_evsel__new_idx()

2018-10-10T06:55:59Z

[ Upstream commit fd8d2702791a970c751f8b526a17d8e725a05b46 ] If evsel is NULL, we should return NULL to avoid a NULL pointer dereference a bit later in the code. Signed-off-by: Hisao Tanabe Acked-by: Namhyung Kim Cc: Jiri Olsa Cc: Wang Nan Fixes: 03e0a7df3efd ("perf tools: Introduce bpf-output event") LPU-Reference: 20180824154556.23428-1-xtanabe@gmail.com Link: https://lkml.kernel.org/n/tip-e5plzjhx6595a5yjaf22jss3@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf evlist: Fix error out while applying initial delay and LBR

2018-09-19T20:41:28Z

[ Upstream commit 95035c5e167ae6e740b1ddd30210ae0eaf39a5db ] 'perf record' will error out if both --delay and LBR are applied. For example: # perf record -D 1000 -a -e cycles -j any -- sleep 2 Error: dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat' # A dummy event is added implicitly for initial delay, which has the same configurations as real sampling events. The dummy event is a software event. If LBR is configured, perf must error out. The dummy event will only be used to track PERF_RECORD_MMAP while perf waits for the initial delay to enable the real events. The BRANCH_STACK bit can be safely cleared for the dummy event. After applying the patch: # perf record -D 1000 -a -e cycles -j any -- sleep 2 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.054 MB perf.data (828 samples) ] # Reported-by: Sunil K Pandey Signed-off-by: Kan Liang Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Andi Kleen Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1531145722-16404-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf evsel: Add has_callchain() helper to make code more compact/clear

2018-06-05T13:09:54Z

Its common to have the (evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN), so add an evsel__has_callchain(evsel) helper. This will actually get more uses as we check that instead of symbol_conf.use_callchain in places where that produces the same result but makes this decision to be more fine grained, per evsel. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-145340oytbthatpfeaq1do18@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: No need to unconditionally read the max_stack sysctls

2018-05-17T19:31:32Z

Let tools that need to have those variables with the sysctl current values use a function that will read them. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-1ljj3oeo5kpt2n1icfd9vowe@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Only fall back group read for leader

2018-04-24T19:11:59Z

Perf doesn't support mixed events from different PMUs (except software event) in a group. The perf stat should output / for all events, but it doesn't. For example, perf stat -e '{cycles,uncore_imc_5/umask=0xF,event=0x4/,instructions}' cycles uncore_imc_5/umask=0xF,event=0x4/ 1,024,300 instructions If perf fails to open an event, it doesn't error out directly. It will disable some features and retry, until the event is opened or all features are disabled. The disabled features will not be re-enabled. The group read is one of these features. For the example as above, the IMC event and the leader event "cycles" are from different PMUs. Opening the IMC event must fail. The group read feature must be disabled for IMC event and the followed event "instructions". The "instructions" event has the same PMU as the leader "cycles". It can be opened successfully. Since the group read feature has been disabled, the "instructions" event will be read as a single event, which definitely has a value. The group read fallback is still useful for the case which kernel doesn't support group read. It is good enough to be handled only by the leader. For the fallback request from members, it must be caused by an error. The fallback only breaks the semantics of group. Limit the group read fallback only for the leader. Committer testing: On a broadwell t450s notebook: Before: # perf stat -e '{cycles,unc_cbo_cache_lookup.read_i,instructions}' sleep 1 Performance counter stats for 'sleep 1': cycles unc_cbo_cache_lookup.read_i 818,206 instructions 1.003170887 seconds time elapsed Some events weren't counted. Try disabling the NMI watchdog: echo 0 > /proc/sys/kernel/nmi_watchdog perf stat ... echo 1 > /proc/sys/kernel/nmi_watchdog After: # perf stat -e '{cycles,unc_cbo_cache_lookup.read_i,instructions}' sleep 1 Performance counter stats for 'sleep 1': cycles unc_cbo_cache_lookup.read_i instructions 1.001380511 seconds time elapsed Some events weren't counted. Try disabling the NMI watchdog: echo 0 > /proc/sys/kernel/nmi_watchdog perf stat ... echo 1 > /proc/sys/kernel/nmi_watchdog # Reported-by: Andi Kleen Signed-off-by: Kan Liang Tested-by: Arnaldo Carvalho de Melo Cc: Agustin Vega-Frias Cc: Ganapatrao Kulkarni Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Shaokun Zhang Cc: Will Deacon Fixes: 82bf311e15d2 ("perf stat: Use group read for event groups") Link: http://lkml.kernel.org/r/1524594014-79243-3-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Disable write_backward for leader sampling group events

2018-04-23T14:21:56Z

.. and other related fields that do not need to be enabled for events that have sampling leader. It fixes the perf top usage Ingo reported broken: # perf top -e '{cycles,msr/aperf/}:S' The 'msr/aperf/' event is configured for write_back sampling, which is not allowed by the MSR PMU, so it fails to create the event. Adjusting related attr test. Reported-by: Ingo Molnar Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: David Ahern Cc: Kan Liang Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20180423090823.32309-6-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Keep the / modifier separator in fallback

2018-04-23T14:14:10Z

The 'perf stat' fallback for EACCES error sets the exclude_kernel perf_event_attr and tries perf_event_open() again with it. In addition, it also changes the name of the event to reflect that change by adding the 'u' modifier. But it does not take into account the '/' separator, so the event name can end up mangled, like: (note the '/:' characters) $ perf stat -e cpu/cpu-cycles/ kill ... 386,832 cpu/cpu-cycles/:u Adding the code to check on the '/' separator and set the following correct event name: $ perf stat -e cpu/cpu-cycles/ kill ... 388,548 cpu/cpu-cycles/u Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20180423090823.32309-4-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Remove suggestion to enable APIC

2018-04-18T18:35:50Z

'perf record' suggests to enable the APIC on errors. APIC is practically always used today and the problem is usually somewhere else. Just remove the outdated suggestion. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20180406203812.3087-5-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Remove misleading error suggestion

2018-04-18T18:35:49Z

When perf record encounters an error setting up an event it suggests to enable CONFIG_PERF_EVENTS. This is misleading because: - Usually it is enabled (it is really hard to disable on x86) - The problem is usually somewhere else, e.g. the CPU is not supported or an invalid configuration has been used. Remove the misleading suggestion. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20180406203812.3087-4-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo