Hi Steve, I’ve identified the cause: these changes stem from trailing whitespace, which my IDE automatically trims by default. I’ll disable this setting to avoid generating large diffs going forward. Do I need to revert these changes? I don’t think it matters, but I’d appreciate your guidance. BR, Jemmy > On Feb 20, 2025, at 2:42 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > On Thu, 20 Feb 2025 02:20:19 +0800 > Jemmy Wong <jemmywong512@xxxxxxxxx> wrote: > >> +++ b/Documentation/trace/ftrace.rst >> @@ -986,14 +986,14 @@ why a latency happened. Here is a typical trace:: >> # => ended at: _raw_spin_unlock_irqrestore >> # >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / > > What exactly did you change for all these header updates? > > -- Steve > >> ps-6143 2d... 0us!: trace_hardirqs_off <-__lock_task_sighand >> ps-6143 2d..1 259us+: trace_hardirqs_on <-_raw_spin_unlock_irqrestore >> ps-6143 2d..1 263us+: time_hardirqs_on <-_raw_spin_unlock_irqrestore >> @@ -1490,14 +1490,14 @@ an example:: >> # => ended at: run_timer_softirq >> # >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> <idle>-0 0d.s2 0us+: _raw_spin_lock_irq <-run_timer_softirq >> <idle>-0 0dNs3 17us : _raw_spin_unlock_irq <-run_timer_softirq >> <idle>-0 0dNs3 17us+: trace_hardirqs_on <-run_timer_softirq >> @@ -1541,14 +1541,14 @@ function-trace, we get a much larger output:: >> # => ended at: ata_scsi_queuecmd >> # >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> bash-2042 3d... 0us : _raw_spin_lock_irqsave <-ata_scsi_queuecmd >> bash-2042 3d... 0us : add_preempt_count <-_raw_spin_lock_irqsave >> bash-2042 3d..1 1us : ata_scsi_find_dev <-ata_scsi_queuecmd >> @@ -1689,14 +1689,14 @@ is much like the irqsoff tracer. >> # => ended at: do_IRQ >> # >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> sshd-1991 1d.h. 0us+: irq_enter <-do_IRQ >> sshd-1991 1d..1 46us : irq_exit <-do_IRQ >> sshd-1991 1d..1 47us+: trace_preempt_on <-do_IRQ >> @@ -1727,14 +1727,14 @@ was over. >> # => ended at: task_rq_unlock >> # >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> bash-1994 1d..1 0us : _raw_spin_lock_irqsave <-wake_up_new_task >> bash-1994 1d..1 0us : select_task_rq_fair <-select_task_rq >> bash-1994 1d..1 1us : __rcu_read_lock <-select_task_rq_fair >> @@ -1841,14 +1841,14 @@ tracers. >> # => ended at: ata_scsi_queuecmd >> # >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> ls-2230 3d... 0us+: _raw_spin_lock_irqsave <-ata_scsi_queuecmd >> ls-2230 3...1 100us : _raw_spin_unlock_irqrestore <-ata_scsi_queuecmd >> ls-2230 3...1 101us+: trace_preempt_on <-ata_scsi_queuecmd >> @@ -1894,14 +1894,14 @@ Here is a trace with function-trace set:: >> # => ended at: mutex_unlock >> # >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> kworker/-59 3...1 0us : __schedule <-schedule >> kworker/-59 3d..1 0us : rcu_preempt_qs <-rcu_note_context_switch >> kworker/-59 3d..1 1us : add_preempt_count <-_raw_spin_lock_irq >> @@ -1987,7 +1987,7 @@ wakeup >> One common case that people are interested in tracing is the >> time it takes for a task that is woken to actually wake up. >> Now for non Real-Time tasks, this can be arbitrary. But tracing >> -it nonetheless can be interesting. >> +it nonetheless can be interesting. >> >> Without function tracing:: >> >> @@ -2007,14 +2007,14 @@ Without function tracing:: >> # | task: kworker/3:1H-312 (uid:0 nice:-20 policy:0 rt_prio:0) >> # ----------------- >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> <idle>-0 3dNs7 0us : 0:120:R + [003] 312:100:R kworker/3:1H >> <idle>-0 3dNs7 1us+: ttwu_do_activate.constprop.87 <-try_to_wake_up >> <idle>-0 3d..3 15us : __schedule <-schedule >> @@ -2076,14 +2076,14 @@ Instead of performing an 'ls', we will run 'sleep 1' under >> # | task: sleep-2389 (uid:0 nice:0 policy:1 rt_prio:5) >> # ----------------- >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | / >> <idle>-0 3d.h4 0us : 0:120:R + [003] 2389: 94:R sleep >> <idle>-0 3d.h4 1us+: ttwu_do_activate.constprop.87 <-try_to_wake_up >> <idle>-0 3d..3 5us : __schedule <-schedule >> @@ -2125,19 +2125,19 @@ Doing the same with chrt -r 5 and function-trace set. >> # | task: sleep-2448 (uid:0 nice:0 policy:1 rt_prio:5) >> # ----------------- >> # >> - # _------=> CPU# >> - # / _-----=> irqs-off >> - # | / _----=> need-resched >> - # || / _---=> hardirq/softirq >> - # ||| / _--=> preempt-depth >> - # |||| / delay >> - # cmd pid ||||| time | caller >> - # \ / ||||| \ | / >> + # _------=> CPU# >> + # / _-----=> irqs-off >> + # | / _----=> need-resched >> + # || / _---=> hardirq/softirq >> + # ||| / _--=> preempt-depth >> + # |||| / delay >> + # cmd pid ||||| time | caller >> + # \ / ||||| \ | /
