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blktrace: print out BLK_TN_MESSAGE properly 

Impact: improve ftrace plugin output

Before this patch:

 # cat trace
         make-5383  [001]   741.240059:   8,7    P   N [make]
 __trace_note_message: cfq1074

 # echo 1 > options/blk_classic
 # cat trace
   8,7    1     0.692221252     0  C   W 130411392 + 1024 [0]
 Bad pc action 6361
 Bad pc action 283d

 # echo 0 > options/blk_classic
 # echo bin > trace_options
 # cat trace_pipe | blkparse -i -
 (can't parse messages generated by blk_add_trace_msg())

After this patch:
 # cat trace
      <idle>-0     [001]   187.600933:   8,7    C   W 145220224 + 8 [0]
      <idle>-0     [001]   187.600946:   8,7    m   N cfq1076 complete

 # echo 1 > options/blk_classic
 # cat trace
   8,7    1     0.256378996   238  I   W 113190728 + 8 [pdflush]
   8,7    1     0.256378998   238  m   N cfq1076 insert_request

 # echo 0 > options/blk_classic
 # echo bin > trace_options
 # cat trace_pipe | blkparse -i -
  8,7    1        0    22.973250293     0  C   W 102770576 + 8 [0]
  8,7    1        0    22.973259213     0  m   N cfq1076 complete

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Li Zefan 2009-03-27 10:21:54 +08:00 committed by Ingo Molnar
parent b6a4b0c3ad
commit 18cea4591a
1 changed files with 61 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

80
kernel/trace/blktrace.c
View File

@ -59,22 +59,39 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
const void *data, size_t len)
{
struct blk_io_trace *t;
struct ring_buffer_event *event = NULL;
int pc = 0;
int cpu = smp_processor_id();
bool blk_tracer = blk_tracer_enabled;
if (blk_tracer) {
pc = preempt_count();
event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK,
sizeof(*t) + len,
0, pc);
if (!event)
return;
t = ring_buffer_event_data(event);
goto record_it;
}
if (!bt->rchan)
return;
t = relay_reserve(bt->rchan, sizeof(*t) + len);
if (t) {
const int cpu = smp_processor_id();
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
t->time = ktime_to_ns(ktime_get());
record_it:
t->device = bt->dev;
t->action = action;
t->pid = pid;
t->cpu = cpu;
t->pdu_len = len;
memcpy((void *) t + sizeof(*t), data, len);
if (blk_tracer)
trace_buffer_unlock_commit(blk_tr, event, 0, pc);
}
}
@ -110,14 +127,8 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
unsigned long flags;
char *buf;
if (blk_tracer_enabled) {
va_start(args, fmt);
ftrace_vprintk(fmt, args);
va_end(args);
return;
}
if (!bt->msg_data)
if (unlikely(bt->trace_state != Blktrace_running &&
!blk_tracer_enabled))
return;
local_irq_save(flags);
@ -168,9 +179,9 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
unsigned long *sequence;
pid_t pid;
int cpu, pc = 0;
bool blk_tracer = blk_tracer_enabled;
if (unlikely(bt->trace_state != Blktrace_running &&
!blk_tracer_enabled))
if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
return;
what |= ddir_act[rw & WRITE];
@ -185,7 +196,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
return;
cpu = raw_smp_processor_id();
if (blk_tracer_enabled) {
if (blk_tracer) {
tracing_record_cmdline(current);
pc = preempt_count();
@ -235,7 +246,7 @@ record_it:
if (pdu_len)
memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
if (blk_tracer_enabled) {
if (blk_tracer) {
trace_buffer_unlock_commit(blk_tr, event, 0, pc);
return;
}
@ -922,6 +933,11 @@ static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
int i = 0;
int tc = t->action >> BLK_TC_SHIFT;
if (t->action == BLK_TN_MESSAGE) {
rwbs[i++] = 'N';
goto out;
}
if (tc & BLK_TC_DISCARD)
rwbs[i++] = 'D';
else if (tc & BLK_TC_WRITE)
@ -939,7 +955,7 @@ static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
rwbs[i++] = 'S';
if (tc & BLK_TC_META)
rwbs[i++] = 'M';
out:
rwbs[i] = '\0';
}
@ -1074,6 +1090,17 @@ static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
get_pdu_int(ent), cmd);
}
static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
{
int ret;
const struct blk_io_trace *t = te_blk_io_trace(ent);
ret = trace_seq_putmem(s, t + 1, t->pdu_len);
if (ret)
return trace_seq_putc(s, '\n');
return ret;
}
/*
* struct tracer operations
*/
@ -1146,6 +1173,13 @@ static enum print_line_t print_one_line(struct trace_iterator *iter,
long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
log_action = classic ? &blk_log_action_classic : &blk_log_action;
if (t->action == BLK_TN_MESSAGE) {
ret = log_action(iter, long_act ? "message" : "m");
if (ret)
ret = blk_log_msg(s, iter->ent);
goto out;
}
if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
ret = trace_seq_printf(s, "Bad pc action %x\n", what);
else {
@ -1153,7 +1187,7 @@ static enum print_line_t print_one_line(struct trace_iterator *iter,
if (ret)
ret = what2act[what].print(s, iter->ent);
}
out:
return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
}
@ -1253,11 +1287,16 @@ static int blk_trace_remove_queue(struct request_queue *q)
static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)
{
struct blk_trace *old_bt, *bt = NULL;
int ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
return -ENOMEM;
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
if (!bt->msg_data)
goto free_bt;
bt->dev = dev;
bt->act_mask = (u16)-1;
bt->end_lba = -1ULL;
@ -1265,14 +1304,17 @@ static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)
old_bt = xchg(&q->blk_trace, bt);
if (old_bt != NULL) {
(void)xchg(&q->blk_trace, old_bt);
kfree(bt);
return -EBUSY;
ret = -EBUSY;
goto free_bt;
}
if (atomic_inc_return(&blk_probes_ref) == 1)
blk_register_tracepoints();
return 0;
free_bt:
blk_trace_free(bt);
return ret;
}
/*