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| author | Steven Rostedt <rostedt@goodmis.org> | 2008-05-12 21:21:01 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2008-05-23 21:56:02 +0200 |
| commit | 53d0aa773053ab18287781e25d52c5faf9e0e09e (patch) | |
| tree | c0e268cb22a0416efca8709c677d41b513af04d3 | |
| parent | 72b59d67f80983f7bb587b086fb4cb1bc95263a4 (diff) | |
| download | blackbird-op-linux-53d0aa773053ab18287781e25d52c5faf9e0e09e.tar.gz blackbird-op-linux-53d0aa773053ab18287781e25d52c5faf9e0e09e.zip | |
ftrace: add logic to record overruns
This patch sets up the infrastructure to record overruns of the tracing
buffer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | kernel/trace/trace.c | 16 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 6 |
2 files changed, 16 insertions, 6 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1281969103b8..b9126ef46a9e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -609,6 +609,7 @@ void unregister_tracer(struct tracer *type) void tracing_reset(struct trace_array_cpu *data) { data->trace_idx = 0; + data->overrun = 0; data->trace_head = data->trace_tail = head_page(data); data->trace_head_idx = 0; data->trace_tail_idx = 0; @@ -750,6 +751,7 @@ tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) if (data->trace_head == data->trace_tail && idx_next == data->trace_tail_idx) { /* overrun */ + data->overrun++; data->trace_tail_idx++; if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { data->trace_tail = @@ -2353,8 +2355,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, { struct trace_iterator *iter = filp->private_data; struct trace_array_cpu *data; - struct trace_array *tr = iter->tr; - struct tracer *tracer = iter->trace; static cpumask_t mask; static int start; unsigned long flags; @@ -2433,10 +2433,11 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, if (cnt >= PAGE_SIZE) cnt = PAGE_SIZE - 1; - memset(iter, 0, sizeof(*iter)); - iter->tr = tr; - iter->trace = tracer; + /* reset all but tr, trace, and overruns */ iter->pos = -1; + memset(&iter->seq, 0, + sizeof(struct trace_iterator) - + offsetof(struct trace_iterator, seq)); /* * We need to stop all tracing on all CPUS to read the @@ -2465,6 +2466,11 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, for_each_cpu_mask(cpu, mask) { data = iter->tr->data[cpu]; __raw_spin_lock(&data->lock); + + if (data->overrun > iter->last_overrun[cpu]) + iter->overrun[cpu] += + data->overrun - iter->last_overrun[cpu]; + iter->last_overrun[cpu] = data->overrun; } while (find_next_entry_inc(iter) != NULL) { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 8991c5efcc74..c1ec134ac356 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -97,6 +97,7 @@ struct trace_array_cpu { void *trace_head; /* producer */ void *trace_tail; /* consumer */ unsigned long trace_idx; + unsigned long overrun; unsigned long saved_latency; unsigned long critical_start; unsigned long critical_end; @@ -157,10 +158,13 @@ struct trace_seq { * results to users and which routines might sleep, etc: */ struct trace_iterator { - struct trace_seq seq; struct trace_array *tr; struct tracer *trace; + long last_overrun[NR_CPUS]; + long overrun[NR_CPUS]; + /* The below is zeroed out in pipe_read */ + struct trace_seq seq; struct trace_entry *ent; int cpu; |
