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tracing: add lock depth to entries

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This patch adds the lock depth of the big kernel lock to the generic
entry header. This way we can see the depth of the lock and help
in removing the BKL.

Example:

 #                  _------=> CPU#
 #                 / _-----=> irqs-off
 #                | / _----=> need-resched
 #                || / _---=> hardirq/softirq
 #                ||| / _--=> preempt-depth
 #                |||| /_--=> lock-depth
 #                |||||/     delay
 #  cmd     pid   |||||| time  |   caller
 #     \   /      ||||||   \   |   /
   <idle>-0       2.N..3 5902255250us+: lock_acquire: read rcu_read_lock
   <idle>-0       2.N..3 5902255253us+: lock_release: rcu_read_lock
   <idle>-0       2dN..3 5902255257us+: lock_acquire: xtime_lock
   <idle>-0       2dN..4 5902255259us : lock_acquire: clocksource_lock
   <idle>-0       2dN..4 5902255261us+: lock_release: clocksource_lock

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt
2009-09-11 13:55:35 -04:00
committed by Steven Rostedt
parent 48659d3119
commit 637e7e8641
5 changed files with 31 additions and 10 deletions
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16
kernel/trace/trace_functions_graph.c
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@ -368,6 +368,7 @@ static enum print_line_t
print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
{
int hardirq, softirq;
int ret;
hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
@ -382,6 +383,13 @@ print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
hardirq ? 'h' : softirq ? 's' : '.'))
return 0;
if (entry->lock_depth < 0)
ret = trace_seq_putc(s, '.');
else
ret = trace_seq_printf(s, "%d", entry->lock_depth);
if (!ret)
return 0;
if (entry->preempt_count)
return trace_seq_printf(s, "%x", entry->preempt_count);
return trace_seq_puts(s, ".");
@ -1001,8 +1009,8 @@ static void print_lat_header(struct seq_file *s)
seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
seq_printf(s, "#%.*s||| / \n", size, spaces);
seq_printf(s, "#%.*s|||| \n", size, spaces);
seq_printf(s, "#%.*s||| / _-=> lock-depth \n", size, spaces);
seq_printf(s, "#%.*s|||| / \n", size, spaces);
}
static void print_graph_headers(struct seq_file *s)
@ -1021,7 +1029,7 @@ static void print_graph_headers(struct seq_file *s)
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
seq_printf(s, " TASK/PID ");
if (lat)
seq_printf(s, "||||");
seq_printf(s, "|||||");
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
seq_printf(s, " DURATION ");
seq_printf(s, " FUNCTION CALLS\n");
@ -1035,7 +1043,7 @@ static void print_graph_headers(struct seq_file *s)
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
seq_printf(s, " | | ");
if (lat)
seq_printf(s, "||||");
seq_printf(s, "|||||");
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
seq_printf(s, " | | ");
seq_printf(s, " | | | |\n");