[PATCH 4/4] tracing/histogram: Fix stacktrace histogram Documententation
From: Tom Zanussi
Date: Fri Feb 10 2023 - 16:33:33 EST
Fix a small problem with the histogram specification in the
Documentation, and change the example to show output using a
stacktrace field rather than the global stacktrace.
Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
Documentation/trace/histogram.rst | 156 +++++++++++++++++-------------
1 file changed, 90 insertions(+), 66 deletions(-)
diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index 5c391328b9bb..d024cdae4fbd 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -1992,82 +1992,106 @@ uninterruptible state:
A synthetic event that has a stacktrace field may use it as a key in histogram:
- # echo 'hist:delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger
+ # echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger
# cat events/synthetic/block_lat/hist
# event histogram
#
- # trigger info: hist:keys=delta.buckets=100,stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active]
+ # trigger info: hist:keys=delta.buckets=100,stack.stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active]
#
-
- { delta: ~ 0-99, stacktrace:
- event_hist_trigger+0x464/0x480
- event_triggers_call+0x52/0xe0
- trace_event_buffer_commit+0x193/0x250
- trace_event_raw_event_sched_switch+0xfc/0x150
- __traceiter_sched_switch+0x41/0x60
- __schedule+0x448/0x7b0
- schedule_idle+0x26/0x40
- cpu_startup_entry+0x19/0x20
- start_secondary+0xed/0xf0
- secondary_startup_64_no_verify+0xe0/0xeb
- } hitcount: 6
- { delta: ~ 0-99, stacktrace:
- event_hist_trigger+0x464/0x480
- event_triggers_call+0x52/0xe0
- trace_event_buffer_commit+0x193/0x250
- trace_event_raw_event_sched_switch+0xfc/0x150
- __traceiter_sched_switch+0x41/0x60
- __schedule+0x448/0x7b0
- schedule_idle+0x26/0x40
- cpu_startup_entry+0x19/0x20
- __pfx_kernel_init+0x0/0x10
- arch_call_rest_init+0xa/0x24
- start_kernel+0x964/0x98d
- secondary_startup_64_no_verify+0xe0/0xeb
+ { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
+ schedule+0x6b/0x110
+ io_schedule+0x46/0x80
+ bit_wait_io+0x11/0x80
+ __wait_on_bit+0x4e/0x120
+ out_of_line_wait_on_bit+0x8d/0xb0
+ __wait_on_buffer+0x33/0x40
+ jbd2_journal_commit_transaction+0x155a/0x19b0
+ kjournald2+0xab/0x270
+ kthread+0xfa/0x130
+ ret_from_fork+0x29/0x50
+ } hitcount: 1
+ { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
+ schedule+0x6b/0x110
+ io_schedule+0x46/0x80
+ rq_qos_wait+0xd0/0x170
+ wbt_wait+0x9e/0xf0
+ __rq_qos_throttle+0x25/0x40
+ blk_mq_submit_bio+0x2c3/0x5b0
+ __submit_bio+0xff/0x190
+ submit_bio_noacct_nocheck+0x25b/0x2b0
+ submit_bio_noacct+0x20b/0x600
+ submit_bio+0x28/0x90
+ ext4_bio_write_page+0x1e0/0x8c0
+ mpage_submit_page+0x60/0x80
+ mpage_process_page_bufs+0x16c/0x180
+ mpage_prepare_extent_to_map+0x23f/0x530
+ } hitcount: 1
+ { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
+ schedule+0x6b/0x110
+ schedule_hrtimeout_range_clock+0x97/0x110
+ schedule_hrtimeout_range+0x13/0x20
+ usleep_range_state+0x65/0x90
+ __intel_wait_for_register+0x1c1/0x230 [i915]
+ intel_psr_wait_for_idle_locked+0x171/0x2a0 [i915]
+ intel_pipe_update_start+0x169/0x360 [i915]
+ intel_update_crtc+0x112/0x490 [i915]
+ skl_commit_modeset_enables+0x199/0x600 [i915]
+ intel_atomic_commit_tail+0x7c4/0x1080 [i915]
+ intel_atomic_commit_work+0x12/0x20 [i915]
+ process_one_work+0x21c/0x3f0
+ worker_thread+0x50/0x3e0
+ kthread+0xfa/0x130
} hitcount: 3
- { delta: ~ 0-99, stacktrace:
- event_hist_trigger+0x464/0x480
- event_triggers_call+0x52/0xe0
- trace_event_buffer_commit+0x193/0x250
- trace_event_raw_event_sched_switch+0xfc/0x150
- __traceiter_sched_switch+0x41/0x60
- __schedule+0x448/0x7b0
- schedule+0x5a/0xb0
- worker_thread+0xaf/0x380
- kthread+0xe9/0x110
- ret_from_fork+0x2c/0x50
+ { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
+ schedule+0x6b/0x110
+ schedule_timeout+0x11e/0x160
+ __wait_for_common+0x8f/0x190
+ wait_for_completion+0x24/0x30
+ __flush_work.isra.0+0x1cc/0x360
+ flush_work+0xe/0x20
+ drm_mode_rmfb+0x18b/0x1d0 [drm]
+ drm_mode_rmfb_ioctl+0x10/0x20 [drm]
+ drm_ioctl_kernel+0xb8/0x150 [drm]
+ drm_ioctl+0x243/0x560 [drm]
+ __x64_sys_ioctl+0x92/0xd0
+ do_syscall_64+0x59/0x90
+ entry_SYSCALL_64_after_hwframe+0x72/0xdc
} hitcount: 1
- { delta: ~ 100-199, stacktrace:
- event_hist_trigger+0x464/0x480
- event_triggers_call+0x52/0xe0
- trace_event_buffer_commit+0x193/0x250
- trace_event_raw_event_sched_switch+0xfc/0x150
- __traceiter_sched_switch+0x41/0x60
- __schedule+0x448/0x7b0
- schedule_idle+0x26/0x40
- cpu_startup_entry+0x19/0x20
- start_secondary+0xed/0xf0
- secondary_startup_64_no_verify+0xe0/0xeb
- } hitcount: 15
- [..]
- { delta: ~ 8500-8599, stacktrace:
- event_hist_trigger+0x464/0x480
- event_triggers_call+0x52/0xe0
- trace_event_buffer_commit+0x193/0x250
- trace_event_raw_event_sched_switch+0xfc/0x150
- __traceiter_sched_switch+0x41/0x60
- __schedule+0x448/0x7b0
- schedule_idle+0x26/0x40
- cpu_startup_entry+0x19/0x20
- start_secondary+0xed/0xf0
- secondary_startup_64_no_verify+0xe0/0xeb
+ { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
+ schedule+0x6b/0x110
+ schedule_timeout+0x87/0x160
+ __wait_for_common+0x8f/0x190
+ wait_for_completion_timeout+0x1d/0x30
+ drm_atomic_helper_wait_for_flip_done+0x57/0x90 [drm_kms_helper]
+ intel_atomic_commit_tail+0x8ce/0x1080 [i915]
+ intel_atomic_commit_work+0x12/0x20 [i915]
+ process_one_work+0x21c/0x3f0
+ worker_thread+0x50/0x3e0
+ kthread+0xfa/0x130
+ ret_from_fork+0x29/0x50
+ } hitcount: 1
+ { delta: ~ 100-199, stack.stacktrace __schedule+0xa19/0x1520
+ schedule+0x6b/0x110
+ schedule_hrtimeout_range_clock+0x97/0x110
+ schedule_hrtimeout_range+0x13/0x20
+ usleep_range_state+0x65/0x90
+ pci_set_low_power_state+0x17f/0x1f0
+ pci_set_power_state+0x49/0x250
+ pci_finish_runtime_suspend+0x4a/0x90
+ pci_pm_runtime_suspend+0xcb/0x1b0
+ __rpm_callback+0x48/0x120
+ rpm_callback+0x67/0x70
+ rpm_suspend+0x167/0x780
+ rpm_idle+0x25a/0x380
+ pm_runtime_work+0x93/0xc0
+ process_one_work+0x21c/0x3f0
} hitcount: 1
Totals:
- Hits: 89
- Entries: 11
- Dropped: 0
+ Hits: 10
+ Entries: 7
+ Dropped: 0
2.2.3 Hist trigger 'handlers' and 'actions'
-------------------------------------------
--
2.34.1