From: Steven Rostedt <[email protected]> By doing:
# trace-cmd sqlhist -e -n futex_wait select TIMESTAMP_DELTA_USECS as lat from sys_enter_futex as start join sys_exit_futex as end on start.common_pid = end.common_pid and # trace-cmd start -e futex_wait -f 'lat > 100' -e page_pool_state_release -f 'pfn == 1' The output of the show_event_trigger and show_event_filter files are well aligned because of the inconsistent 'tab' spacing: ~# cat /sys/kernel/tracing/show_event_triggers syscalls:sys_exit_futex hist:keys=common_pid:vals=hitcount:__lat_12046_2=common_timestamp.usecs-$__arg_12046_1:sort=hitcount:size=2048:clock=global:onmatch(syscalls.sys_enter_futex).trace(futex_wait,$__lat_12046_2) [active] syscalls:sys_enter_futex hist:keys=common_pid:vals=hitcount:__arg_12046_1=common_timestamp.usecs:sort=hitcount:size=2048:clock=global [active] ~# cat /sys/kernel/tracing/show_event_filters synthetic:futex_wait (lat > 100) page_pool:page_pool_state_release (pfn == 1) This makes it not so easy to read. Instead, force the spacing to be at least 32 bytes from the beginning (one space if the system:event is longer than 30 bytes): ~# cat /sys/kernel/tracing/show_event_triggers syscalls:sys_exit_futex hist:keys=common_pid:vals=hitcount:__lat_8125_2=common_timestamp.usecs-$__arg_8125_1:sort=hitcount:size=2048:clock=global:onmatch(syscalls.sys_enter_futex).trace(futex_wait,$__lat_8125_2) [active] syscalls:sys_enter_futex hist:keys=common_pid:vals=hitcount:__arg_8125_1=common_timestamp.usecs:sort=hitcount:size=2048:clock=global [active] ~# cat /sys/kernel/tracing/show_event_filters synthetic:futex_wait (lat > 100) page_pool:page_pool_state_release (pfn == 1) Signed-off-by: Steven Rostedt (Google) <[email protected]> --- [ This is based on top of these patches: https://lore.kernel.org/linux-trace-kernel/[email protected]/ ] kernel/trace/trace_events.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 36936697fa2a..f372a6374164 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1662,6 +1662,18 @@ static void t_stop(struct seq_file *m, void *p) mutex_unlock(&event_mutex); } +static int get_call_len(struct trace_event_call *call) +{ + int len; + + /* Get the length of "<system>:<event>" */ + len = strlen(call->class->system) + 1; + len += strlen(trace_event_name(call)); + + /* Set the index to 32 bytes to separate event from data */ + return len >= 32 ? 1 : 32 - len; +} + /** * t_show_filters - seq_file callback to display active event filters * @m: The seq_file interface for formatted output @@ -1676,14 +1688,17 @@ static int t_show_filters(struct seq_file *m, void *v) struct trace_event_file *file = v; struct trace_event_call *call = file->event_call; struct event_filter *filter; + int len; guard(rcu)(); filter = rcu_dereference(file->filter); if (!filter || !filter->filter_string) return 0; - seq_printf(m, "%s:%s\t%s\n", call->class->system, - trace_event_name(call), filter->filter_string); + len = get_call_len(call); + + seq_printf(m, "%s:%s%*.s%s\n", call->class->system, + trace_event_name(call), len, "", filter->filter_string); return 0; } @@ -1702,6 +1717,7 @@ static int t_show_triggers(struct seq_file *m, void *v) struct trace_event_file *file = v; struct trace_event_call *call = file->event_call; struct event_trigger_data *data; + int len; /* * The event_mutex is held by t_start(), protecting the @@ -1710,9 +1726,11 @@ static int t_show_triggers(struct seq_file *m, void *v) if (list_empty(&file->triggers)) return 0; + len = get_call_len(call); + list_for_each_entry_rcu(data, &file->triggers, list) { - seq_printf(m, "%s:%s\t", call->class->system, - trace_event_name(call)); + seq_printf(m, "%s:%s%*.s", call->class->system, + trace_event_name(call), len, ""); data->cmd_ops->print(m, data); } -- 2.51.0
