diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2009-09-11 13:55:35 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2009-09-11 13:55:35 -0400 |
| commit | 637e7e864103a7a68c1ce43ada27dfc25c0d113f (patch) | |
| tree | 7ef0eadf41d79b07bc19f62b1355f7c824d781fd /kernel/trace/trace_output.c | |
| parent | 48659d31195bb76d688e99dabd816c5472fb1656 (diff) | |
tracing: add lock depth to entries
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>
Diffstat (limited to 'kernel/trace/trace_output.c')
| -rw-r--r-- | kernel/trace/trace_output.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index be34a6aa7e4d..29a370a45582 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -465,6 +465,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) { int hardirq, softirq; char comm[TASK_COMM_LEN]; + int ret; trace_find_cmdline(entry->pid, comm); hardirq = entry->flags & TRACE_FLAG_HARDIRQ; @@ -481,9 +482,16 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) 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, "."); + return trace_seq_putc(s, '.'); } static unsigned long preempt_mark_thresh = 100; |