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ftrace: mmiotrace, updates

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here is a patch that makes mmiotrace work almost well within the tracing
framework. The patch applies on top of my previous patch. I have my own
output formatting in place now.

Summary of changes:
- fix the NULL dereference that was due to not calling tracing_reset()
- add print_line() callback into struct tracer
- implement print_line() for mmiotrace, producing up-to-spec text
- add my output header, but that is not really called in the right place
- rewrote the main structs in mmiotrace
- added two new trace entry types: TRACE_MMIO_RW and TRACE_MMIO_MAP
- made some functions in trace.c non-static
- check current==NULL in tracing_generic_entry_update()
- fix(?) comparison in trace_seq_printf()

Things seem to work fine except a few issues. Markers (text lines injected
into mmiotrace log) are missing, I did not feel hacking them in before we
have variable length entries. My output header is printed only for 'trace'
file, but not 'trace_pipe'. For some reason, despite my quick fix,
iter->trace is NULL in print_trace_line() when called from 'trace_pipe'
file, which means I don't get proper output formatting.

I only tried by loading nouveau.ko, which just detects the card, and that
is traced fine. I didn't try further. Map, two reads and unmap. Works
perfectly.

I am missing the information about overflows, I'd prefer to have a
counter for lost events. I didn't try, but I guess currently there is no
way of knowning when it overflows?

So, not too far from being fully operational, it seems :-)
And looking at the diffstat, there also is some 700-900 lines of user space
code that just became obsolete.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Pekka Paalanen
2008-05-12 21:20:57 +02:00
committed by Thomas Gleixner
parent f984b51e07
commit bd8ac686c7
6 changed files with 242 additions and 192 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
kernel/trace/trace.c
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@@ -831,6 +831,40 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
trace_function(tr, data, ip, parent_ip, flags);
}
#ifdef CONFIG_MMIOTRACE
void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data,
struct mmiotrace_rw *rw)
{
struct trace_entry *entry;
unsigned long irq_flags;
spin_lock_irqsave(&data->lock, irq_flags);
entry = tracing_get_trace_entry(tr, data);
tracing_generic_entry_update(entry, 0);
entry->type = TRACE_MMIO_RW;
entry->mmiorw = *rw;
spin_unlock_irqrestore(&data->lock, irq_flags);
trace_wake_up();
}
void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data,
struct mmiotrace_map *map)
{
struct trace_entry *entry;
unsigned long irq_flags;
spin_lock_irqsave(&data->lock, irq_flags);
entry = tracing_get_trace_entry(tr, data);
tracing_generic_entry_update(entry, 0);
entry->type = TRACE_MMIO_MAP;
entry->mmiomap = *map;
spin_unlock_irqrestore(&data->lock, irq_flags);
trace_wake_up();
}
#endif
void __trace_stack(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long flags,