linux-toradex.git/kernel/trace/trace_functions_graph.c, branch v2.6.30.8

tracing: Fix invalid function_graph entry

2009-08-16T21:18:35+00:00

commit 38ceb592fcac9110c6b3c87ea0a27bff68c43486 upstream.

When print_graph_entry() computes a function call entry event, it needs
to also check the next entry to guess if it matches the return event of
the current function entry.
In order to look at this next event, it needs to consume the current
entry before going ahead in the ring buffer.

However, if the current event that gets consumed is the last one in the
ring buffer head page, the ring_buffer may reuse the page for writers.
The consumed entry will then become invalid because of possible
racy overwriting.

Me must then handle this entry by making a copy of it.

The fix also applies on 2.6.30

Signed-off-by: Lai Jiangshan 
Cc: Steven Rostedt 
LKML-Reference: <4A6EEAEC.3050508@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker 
Signed-off-by: Greg Kroah-Hartman

function-graph: moved the timestamp from arch to generic code

2009-03-24T13:31:34+00:00

This patch move the timestamp from happening in the arch specific
code into the general code. This allows for better control by the tracer
to time manipulation.

Signed-off-by: Steven Rostedt

function-graph: show binary events as comments

2009-03-19T19:58:56+00:00

With the added TRACE_EVENT macro, the events no longer appear in
the function graph tracer. This was because the function graph
did not know how to display the entries. The graph tracer was
only aware of its own entries and the printk entries.

By using the event call back feature, the graph tracer can now display
the events.

 # echo irq > /debug/tracing/set_event

Which can show:

 0)               |          handle_IRQ_event() {
 0)               |            /* irq_handler_entry: irq=48 handler=eth0 */
 0)               |            e1000_intr() {
 0)   0.926 us    |              __napi_schedule();
 0)   3.888 us    |            }
 0)               |            /* irq_handler_exit: irq=48 return=handled */
 0)   0.655 us    |            runqueue_is_locked();
 0)               |            __wake_up() {
 0)   0.831 us    |              _spin_lock_irqsave();

The irq entry and exit events show up as comments.

Signed-off-by: Steven Rostedt

function-graph: calculate function depth within function graph tracer

2009-03-19T19:58:38+00:00

Currently, the function graph tracer depends on the trace_printk
to record the depth. All the information is already there in the trace
to calculate function depth, with the exception of having the printk
be the first item. But as soon as a entry or exit is reached, then
we know the depth.

This patch changes the iter->private data from recording a per cpu
last_pid, to a structure that holds both the last_pid and the current
depth. This data is used to determine the function depth for the
printks.

Signed-off-by: Steven Rostedt

function-graph: consolidate prologues for output

2009-03-19T15:29:23+00:00

Impact: clean up

The prologue of the function graph entry, return and comments all
start out pretty much the same. Each of these duplicate code and
do so slightly differently.

This patch consolidates the printing of the pid, absolute time,
cpu and proc (and for entry, the interrupt).

Signed-off-by: Steven Rostedt

tracing: protect reader of cmdline output

2009-03-17T03:27:06+00:00

Impact: fix to one cause of incorrect comm outputs in trace

The spinlock only protected the creation of a comm <=> pid pair.
But it was possible that a reader could look up a pid, and get the
wrong comm because it had no locking.

This also required changing trace_find_cmdline to copy the comm cache
and not just send back a pointer to it.

Signed-off-by: Steven Rostedt

tracing/core: bring back raw trace_printk for dynamic formats strings

2009-03-13T01:15:00+00:00

Impact: fix callsites with dynamic format strings

Since its new binary implementation, trace_printk() internally uses static
containers for the format strings on each callsites. But the value is
assigned once at build time, which means that it can't take dynamic
formats.

So this patch unearthes the raw trace_printk implementation for the callers
that will need trace_printk to be able to carry these dynamic format
strings. The trace_printk() macro will use the appropriate implementation
for each callsite. Most of the time however, the binary implementation will
still be used.

The other impact of this patch is that mmiotrace_printk() will use the old
implementation because it calls the low level trace_vprintk and we can't
guess here whether the format passed in it is dynamic or not.

Some parts of this patch have been written by Steven Rostedt (most notably
the part that chooses the appropriate implementation for each callsites).

Signed-off-by: Frederic Weisbecker 
Signed-off-by: Steven Rostedt

Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

2009-03-10T21:55:31+00:00

tracing: remove funky whitespace in the trace code

2009-03-10T18:13:14+00:00

Impact: clean up

There existed a lot of 's in the tracing code. This
patch removes them.

Signed-off-by: Steven Rostedt

Merge branch 'x86/core' into tracing/ftrace

2009-03-10T09:17:48+00:00

Semantic merge:

  kernel/trace/trace_functions_graph.c

Signed-off-by: Ingo Molnar