• Howard Chu's avatar
    perf trace: Augment non-syscall tracepoints with enum arguments with BTF · 607bbdb4
    Howard Chu authored
    Before:
    
    perf $ ./perf trace -e timer:hrtimer_start --max-events=1
         0.000 :0/0 timer:hrtimer_start(hrtimer: 0xffff974466c25f18, function: 0xffffffff89da5be0, expires: 377432432256753, softexpires: 377432432256753, mode: 10)
    
    After:
    
    perf $ ./perf trace -e timer:hrtimer_start --max-events=1
         0.000 :0/0 timer:hrtimer_start(hrtimer: 0xffff9498a6ca5f18, function: 0xffffffffa77a5be0, expires: 4382442895089, softexpires: 4382442895089, mode: HRTIMER_MODE_ABS_PINNED_HARD)
    
    in which HRTIMER_MODE_ABS_PINNED_HARD is:
    
    perf $ pahole hrtimer_mode
    enum hrtimer_mode {
            HRTIMER_MODE_ABS             = 0,
            HRTIMER_MODE_REL             = 1,
            HRTIMER_MODE_PINNED          = 2,
            HRTIMER_MODE_SOFT            = 4,
            HRTIMER_MODE_HARD            = 8,
            HRTIMER_MODE_ABS_PINNED      = 2,
            HRTIMER_MODE_REL_PINNED      = 3,
            HRTIMER_MODE_ABS_SOFT        = 4,
            HRTIMER_MODE_REL_SOFT        = 5,
            HRTIMER_MODE_ABS_PINNED_SOFT = 6,
            HRTIMER_MODE_REL_PINNED_SOFT = 7,
            HRTIMER_MODE_ABS_HARD        = 8,
            HRTIMER_MODE_REL_HARD        = 9,
            HRTIMER_MODE_ABS_PINNED_HARD = 10,
            HRTIMER_MODE_REL_PINNED_HARD = 11,
    };
    
    Can also be tested by
    
    ./perf trace -e pagemap:mm_lru_insertion,timer:hrtimer_start,timer:hrtimer_init,skb:kfree_skb --max-events=10
    
    (Chose these 4 events because they happen quite frequently.)
    
    However some enum arguments may not be contained in vmlinux BTF. To see
    what enum arguments are supported, use:
    
    vmlinux_dir $ bpftool btf dump file /sys/kernel/btf/vmlinux > vmlinux
    
    vmlinux_dir $  while read l; do grep "ENUM '$l'" vmlinux; done < <(grep field:enum /sys/kernel/tracing/events/*/*/format | awk '{print $3}' | sort | uniq) | awk '{print $3}' | sed "s/'\(.*\)'/\1/g"
    dev_pm_qos_req_type
    error_detector
    hrtimer_mode
    i2c_slave_event
    ieee80211_bss_type
    lru_list
    migrate_mode
    nl80211_auth_type
    nl80211_band
    nl80211_iftype
    numa_vmaskip_reason
    pm_qos_req_action
    pwm_polarity
    skb_drop_reason
    thermal_trip_type
    xen_lazy_mode
    xen_mc_extend_args
    xen_mc_flush_reason
    zone_type
    
    And what tracepoints have these enum types as their arguments:
    
    vmlinux_dir $ while read l; do grep "ENUM '$l'" vmlinux; done < <(grep field:enum /sys/kernel/tracing/events/*/*/format | awk '{print $3}' | sort | uniq) | awk '{print $3}' | sed "s/'\(.*\)'/\1/g" > good_enums
    
    vmlinux_dir $ cat good_enums
    dev_pm_qos_req_type
    error_detector
    hrtimer_mode
    i2c_slave_event
    ieee80211_bss_type
    lru_list
    migrate_mode
    nl80211_auth_type
    nl80211_band
    nl80211_iftype
    numa_vmaskip_reason
    pm_qos_req_action
    pwm_polarity
    skb_drop_reason
    thermal_trip_type
    xen_lazy_mode
    xen_mc_extend_args
    xen_mc_flush_reason
    zone_type
    
    vmlinux_dir $ grep -f good_enums -l /sys/kernel/tracing/events/*/*/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_chandef_dfs_required/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_ch_switch_notify/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_ch_switch_started_notify/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_get_bss/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_ibss_joined/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_inform_bss_frame/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_radar_event/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_ready_on_channel_expired/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_ready_on_channel/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_reg_can_beacon/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_return_bss/format
    /sys/kernel/tracing/events/cfg80211/cfg80211_tx_mgmt_expired/format
    /sys/kernel/tracing/events/cfg80211/rdev_add_virtual_intf/format
    /sys/kernel/tracing/events/cfg80211/rdev_auth/format
    /sys/kernel/tracing/events/cfg80211/rdev_change_virtual_intf/format
    /sys/kernel/tracing/events/cfg80211/rdev_channel_switch/format
    /sys/kernel/tracing/events/cfg80211/rdev_connect/format
    /sys/kernel/tracing/events/cfg80211/rdev_inform_bss/format
    /sys/kernel/tracing/events/cfg80211/rdev_libertas_set_mesh_channel/format
    /sys/kernel/tracing/events/cfg80211/rdev_mgmt_tx/format
    /sys/kernel/tracing/events/cfg80211/rdev_remain_on_channel/format
    /sys/kernel/tracing/events/cfg80211/rdev_return_chandef/format
    /sys/kernel/tracing/events/cfg80211/rdev_return_int_survey_info/format
    /sys/kernel/tracing/events/cfg80211/rdev_set_ap_chanwidth/format
    /sys/kernel/tracing/events/cfg80211/rdev_set_monitor_channel/format
    /sys/kernel/tracing/events/cfg80211/rdev_set_radar_background/format
    /sys/kernel/tracing/events/cfg80211/rdev_start_ap/format
    /sys/kernel/tracing/events/cfg80211/rdev_start_radar_detection/format
    /sys/kernel/tracing/events/cfg80211/rdev_tdls_channel_switch/format
    /sys/kernel/tracing/events/compaction/mm_compaction_defer_compaction/format
    /sys/kernel/tracing/events/compaction/mm_compaction_deferred/format
    /sys/kernel/tracing/events/compaction/mm_compaction_defer_reset/format
    /sys/kernel/tracing/events/compaction/mm_compaction_finished/format
    /sys/kernel/tracing/events/compaction/mm_compaction_kcompactd_wake/format
    /sys/kernel/tracing/events/compaction/mm_compaction_suitable/format
    /sys/kernel/tracing/events/compaction/mm_compaction_wakeup_kcompactd/format
    /sys/kernel/tracing/events/error_report/error_report_end/format
    /sys/kernel/tracing/events/i2c_slave/i2c_slave/format
    /sys/kernel/tracing/events/migrate/mm_migrate_pages/format
    /sys/kernel/tracing/events/migrate/mm_migrate_pages_start/format
    /sys/kernel/tracing/events/pagemap/mm_lru_insertion/format
    /sys/kernel/tracing/events/power/dev_pm_qos_add_request/format
    /sys/kernel/tracing/events/power/dev_pm_qos_remove_request/format
    /sys/kernel/tracing/events/power/dev_pm_qos_update_request/format
    /sys/kernel/tracing/events/power/pm_qos_update_flags/format
    /sys/kernel/tracing/events/power/pm_qos_update_target/format
    /sys/kernel/tracing/events/pwm/pwm_apply/format
    /sys/kernel/tracing/events/pwm/pwm_get/format
    /sys/kernel/tracing/events/sched/sched_skip_vma_numa/format
    /sys/kernel/tracing/events/skb/kfree_skb/format
    /sys/kernel/tracing/events/thermal/thermal_zone_trip/format
    /sys/kernel/tracing/events/timer/hrtimer_init/format
    /sys/kernel/tracing/events/timer/hrtimer_start/format
    /sys/kernel/tracing/events/xen/xen_mc_batch/format
    /sys/kernel/tracing/events/xen/xen_mc_extend_args/format
    /sys/kernel/tracing/events/xen/xen_mc_flush_reason/format
    /sys/kernel/tracing/events/xen/xen_mc_issue/format
    
    Committer testing:
    
      root@x1:~# perf trace -e timer:hrtimer_start --max-events=2
           0.000 :0/0 timer:hrtimer_start(hrtimer: 0xffff8d4eff225050, function: 0xffffffff9e22ddd0, expires: 241152380000000, softexpires: 241152380000000, mode: HRTIMER_MODE_ABS)
           0.028 :0/0 timer:hrtimer_start(hrtimer: 0xffff8d4eff225050, function: 0xffffffff9e22ddd0, expires: 241153654000000, softexpires: 241153654000000, mode: HRTIMER_MODE_ABS_PINNED_HARD)
      root@x1:~#
    Suggested-by: default avatarArnaldo Carvalho de Melo <acme@kernel.org>
    Reviewed-by: default avatarArnaldo Carvalho de Melo <acme@kernel.org>
    Signed-off-by: default avatarHoward Chu <howardchu95@gmail.com>
    Tested-by: default avatarArnaldo Carvalho de Melo <acme@kernel.org>
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Ian Rogers <irogers@google.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Kan Liang <kan.liang@linux.intel.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Link: https://lore.kernel.org/lkml/20240615032743.112750-1-howardchu95@gmail.com
    Link: https://lore.kernel.org/r/20240624181345.124764-4-howardchu95@gmail.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    607bbdb4
builtin-trace.c 148 KB