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tracing: Format non-nanosec times from tsc clock without a decimal point.

Browse Source 
With the addition of the "tsc" clock, formatting timestamps to look like
fractional seconds is misleading. Mark clocks as either in nanoseconds or
not, and format non-nanosecond timestamps as decimal integers.

Tested:
$ cd /sys/kernel/debug/tracing/
$ cat trace_clock
[local] global tsc
$ echo sched_switch > set_event
$ echo 1 > tracing_on ; sleep 0.0005 ; echo 0 > tracing_on
$ cat trace
          <idle>-0     [000]  6330.555552: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=29964 next_prio=120
           sleep-29964 [000]  6330.555628: sched_switch: prev_comm=bash prev_pid=29964 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
  ...
$ echo 1 > options/latency-format
$ cat trace
  <idle>-0       0 4104553247us+: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=29964 next_prio=120
   sleep-29964   0 4104553322us+: sched_switch: prev_comm=bash prev_pid=29964 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
  ...
$ echo tsc > trace_clock
$ cat trace
$ echo 1 > tracing_on ; sleep 0.0005 ; echo 0 > tracing_on
$ echo 0 > options/latency-format
$ cat trace
          <idle>-0     [000] 16490053398357: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=31128 next_prio=120
           sleep-31128 [000] 16490053588518: sched_switch: prev_comm=bash prev_pid=31128 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
  ...
echo 1 > options/latency-format
$ cat trace
  <idle>-0       0 91557653238+: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=31128 next_prio=120
   sleep-31128   0 91557843399+: sched_switch: prev_comm=bash prev_pid=31128 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
  ...

v2:
Move arch-specific bits out of generic code.
v4:
Fix x86_32 build due to 64-bit division.

Google-Bug-Id: 6980623
Link: http://lkml.kernel.org/r/1352837903-32191-2-git-send-email-dhsharp@google.com

Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: David Sharp <dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
David Sharp
2012-11-13 12:18:22 -08:00
committed by Steven Rostedt
parent 8cbd9cc625
commit 8be0709f10
5 changed files with 72 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/trace/trace_output.c
+53 -25
View File
@@ -610,24 +610,54 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
return trace_print_lat_fmt(s, entry);
}
static unsigned long preempt_mark_thresh = 100;
static unsigned long preempt_mark_thresh_us = 100;
static int
lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
unsigned long rel_usecs)
lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
{
return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
rel_usecs > preempt_mark_thresh ? '!' :
rel_usecs > 1 ? '+' : ' ');
unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE;
unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
unsigned long long abs_ts = iter->ts - iter->tr->time_start;
unsigned long long rel_ts = next_ts - iter->ts;
struct trace_seq *s = &iter->seq;
if (in_ns) {
abs_ts = ns2usecs(abs_ts);
rel_ts = ns2usecs(rel_ts);
}
if (verbose && in_ns) {
unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
unsigned long abs_msec = (unsigned long)abs_ts;
unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
unsigned long rel_msec = (unsigned long)rel_ts;
return trace_seq_printf(
s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
ns2usecs(iter->ts),
abs_msec, abs_usec,
rel_msec, rel_usec);
} else if (verbose && !in_ns) {
return trace_seq_printf(
s, "[%016llx] %lld (+%lld): ",
iter->ts, abs_ts, rel_ts);
} else if (!verbose && in_ns) {
return trace_seq_printf(
s, " %4lldus%c: ",
abs_ts,
rel_ts > preempt_mark_thresh_us ? '!' :
rel_ts > 1 ? '+' : ' ');
} else { /* !verbose && !in_ns */
return trace_seq_printf(s, " %4lld: ", abs_ts);
}
}
int trace_print_context(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *entry = iter->ent;
unsigned long long t = ns2usecs(iter->ts);
unsigned long usec_rem = do_div(t, USEC_PER_SEC);
unsigned long secs = (unsigned long)t;
unsigned long long t;
unsigned long secs, usec_rem;
char comm[TASK_COMM_LEN];
int ret;
@@ -644,8 +674,13 @@ int trace_print_context(struct trace_iterator *iter)
return 0;
}
return trace_seq_printf(s, " %5lu.%06lu: ",
secs, usec_rem);
if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
t = ns2usecs(iter->ts);
usec_rem = do_div(t, USEC_PER_SEC);
secs = (unsigned long)t;
return trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
} else
return trace_seq_printf(s, " %12llu: ", iter->ts);
}
int trace_print_lat_context(struct trace_iterator *iter)
@@ -659,36 +694,29 @@ int trace_print_lat_context(struct trace_iterator *iter)
*next_entry = trace_find_next_entry(iter, NULL,
&next_ts);
unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
unsigned long rel_usecs;
/* Restore the original ent_size */
iter->ent_size = ent_size;
if (!next_entry)
next_ts = iter->ts;
rel_usecs = ns2usecs(next_ts - iter->ts);
if (verbose) {
char comm[TASK_COMM_LEN];
trace_find_cmdline(entry->pid, comm);
ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
" %ld.%03ldms (+%ld.%03ldms): ", comm,
entry->pid, iter->cpu, entry->flags,
entry->preempt_count, iter->idx,
ns2usecs(iter->ts),
abs_usecs / USEC_PER_MSEC,
abs_usecs % USEC_PER_MSEC,
rel_usecs / USEC_PER_MSEC,
rel_usecs % USEC_PER_MSEC);
ret = trace_seq_printf(
s, "%16s %5d %3d %d %08x %08lx ",
comm, entry->pid, iter->cpu, entry->flags,
entry->preempt_count, iter->idx);
} else {
ret = lat_print_generic(s, entry, iter->cpu);
if (ret)
ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
}
if (ret)
ret = lat_print_timestamp(iter, next_ts);
return ret;
}