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* cpumask: convert kernel trace functions furtherRusty Russell2008-12-31
| | | | | | | | | | | | Impact: Reduce future memory usage, use new cpumask API. Since the last patch was created and acked, more old cpumask users slipped into kernel/trace. Mostly trivial conversions, except struct trace_iterator's "started" member becomes a cpumask_var_t. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* ftrace: introduce tracing_reset_online_cpus() helperPekka J Enberg2008-12-19
| | | | | | | | | | Impact: cleanup This patch factors out common code from multiple tracers into a tracing_reset_online_cpus() function and converts the tracers to use it. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: add the printk-msg-only optionFrederic Weisbecker2008-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | Impact: display ftrace_printk messages "as is" By default, ftrace_printk() messages find their output with some other informations like pid, caller, ... Sometimes a developer just want to have the ftrace_printk left "as is", without other information. This is done by providing a default-off option called printk-msg-only. To enable it, just do `echo printk-msg-only > /debugfs/tracing/trace_options` Before the patch: <...>-2739 [000] 145.692153: __might_sleep: I'm an ftrace_printk msg in __might_sleep <...>-2739 [000] 145.692155: __might_sleep: I'm another ftrace_printk msg in __might_sleep After the patch and the printk-msg-only option enabled: I'm an ftrace_printk msg in __might_sleep I'm another ftrace_printk msg in __might_sleep Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, bts, ftrace: adapt the hw-branch-tracer to the ds.c interfaceMarkus Metzger2008-12-12
| | | | | | | | | | Impact: restructure code, cleanup Remove BTS bits from the hw-branch-tracer (renamed from bts-tracer) and use the ds interface. Signed-off-by: Markus Metzger <markut.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: fix the check of ftrace_trace_taskFrederic Weisbecker2008-12-05
| | | | | | | | | | | | | | | | | | | Impact: fix default empty traces on function-graph-tracer The actual ftrace_trace_task() checks if ftrace_pid_trace is allocated and return 1 if it is true. If it is NULL, it will check the bit of pid tracing flag for the current task (which are not set by default). So by default, a task is not traced. Actually all tasks should be traced by default and filter_by_pid when ftrace_pid_trace is allocated. The appropriate condition should be to return 1 if filter_by_pid is set. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acke-dby: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
*-. Merge branches 'tracing/ftrace', 'tracing/function-graph-tracer' and ↵Ingo Molnar2008-12-05
|\ \ | | | | | | | | | 'tracing/urgent' into tracing/core
| * | tracing/function-graph-tracer: handle ftrace_printk entriesFrederic Weisbecker2008-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handle the TRACE_PRINT entries from the function grapg tracer and output them as a C comment just below the function that called it, as if it was a comment inside this function. Example with an ftrace_printk inside might_sleep() function: void __might_sleep(char *file, int line) { static unsigned long prev_jiffy; /* ratelimiting */ ftrace_printk("Hi I'm a comment in might_sleep() :-)"); A chunk of a resulting trace: 0) | _reiserfs_free_block() { 0) | reiserfs_read_bitmap_block() { 0) | __bread() { 0) | __getblk() { 0) | __find_get_block() { 0) 0.698 us | mark_page_accessed(); 0) 2.267 us | } 0) | __might_sleep() { 0) | /* Hi I'm a comment in might_sleep() :-) */ 0) 1.321 us | } 0) 5.872 us | } 0) 7.313 us | } 0) 8.718 us | } And this patch brings two minor fixes: - The newline after a switch-out task has disappeared - The "|" sign just before the cpu number on task-switch has been deleted. 0) 0.616 us | pick_next_task_rt(); 0) 1.457 us | _spin_trylock(); 0) 0.653 us | _spin_unlock(); 0) 0.728 us | _spin_trylock(); 0) 0.631 us | _spin_unlock(); 0) 0.729 us | native_load_sp0(); 0) 0.593 us | native_load_tls(); ------------------------------------------ 0) cat-2834 => migrati-3 ------------------------------------------ 0) | finish_task_switch() { 0) 0.841 us | _spin_unlock_irq(); 0) 0.616 us | post_schedule_rt(); 0) 3.882 us | } Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | tracing: fix typo and missing inline functionIngo Molnar2008-12-04
| | | | | | | | | | | | | | | | | | Impact: fix build bugs Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | ftrace: use struct pidSteven Rostedt2008-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: clean up, extend PID filtering to PID namespaces Eric Biederman suggested using the struct pid for filtering on pids in the kernel. This patch is based off of a demonstration of an implementation that Eric sent me in an email. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | ftrace: trace single pid for function graph tracerSteven Rostedt2008-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: New feature This patch makes the changes to set_ftrace_pid apply to the function graph tracer. # echo $$ > /debugfs/tracing/set_ftrace_pid # echo function_graph > /debugfs/tracing/current_tracer Will cause only the current task to be traced. Note, the trace flags are also inherited by child processes, so the children of the shell will also be traced. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | ftrace: graph of a single functionSteven Rostedt2008-12-04
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the file: /debugfs/tracing/set_graph_function which can be used along with the function graph tracer. When this file is empty, the function graph tracer will act as usual. When the file has a function in it, the function graph tracer will only trace that function. For example: # echo blk_unplug > /debugfs/tracing/set_graph_function # cat /debugfs/tracing/trace [...] ------------------------------------------ | 2) make-19003 => kjournald-2219 ------------------------------------------ 2) | blk_unplug() { 2) | dm_unplug_all() { 2) | dm_get_table() { 2) 1.381 us | _read_lock(); 2) 0.911 us | dm_table_get(); 2) 1. 76 us | _read_unlock(); 2) + 12.912 us | } 2) | dm_table_unplug_all() { 2) | blk_unplug() { 2) 0.778 us | generic_unplug_device(); 2) 2.409 us | } 2) 5.992 us | } 2) 0.813 us | dm_table_put(); 2) + 29. 90 us | } 2) + 34.532 us | } You can add up to 32 functions into this file. Currently we limit it to 32, but this may change with later improvements. To add another function, use the append '>>': # echo sys_read >> /debugfs/tracing/set_graph_function # cat /debugfs/tracing/set_graph_function blk_unplug sys_read Using the '>' will clear out the function and write anew: # echo sys_write > /debug/tracing/set_graph_function # cat /debug/tracing/set_graph_function sys_write Note, if you have function graph running while doing this, the small time between clearing it and updating it will cause the graph to record all functions. This should not be an issue because after it sets the filter, only those functions will be recorded from then on. If you need to only record a particular function then set this file first before starting the function graph tracer. In the future this side effect may be corrected. The set_graph_function file is similar to the set_ftrace_filter but it does not take wild cards nor does it allow for more than one function to be set with a single write. There is no technical reason why this is the case, I just do not have the time yet to implement that. Note, dynamic ftrace must be enabled for this to appear because it uses the dynamic ftrace records to match the name to the mcount call sites. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: function graph return for function entrySteven Rostedt2008-12-03
| | | | | | | | | | | | | | | | | | | | | | | | Impact: feature, let entry function decide to trace or not This patch lets the graph tracer entry function decide if the tracing should be done at the end as well. This requires all function graph entry functions return 1 if it should trace, or 0 if the return should not be traced. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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*-. \ Merge branches 'tracing/blktrace', 'tracing/ftrace', ↵Ingo Molnar2008-11-27
|\ \ \ | | | | | | | | | | | | 'tracing/function-graph-tracer' and 'tracing/power-tracer' into tracing/core
| | * | tracing: add "power-tracer": C/P state tracer to help power optimizationArjan van de Ven2008-11-26
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: new "power-tracer" ftrace plugin This patch adds a C/P-state ftrace plugin that will generate detailed statistics about the C/P-states that are being used, so that we can look at detailed decisions that the C/P-state code is making, rather than the too high level "average" that we have today. An example way of using this is: mount -t debugfs none /sys/kernel/debug echo cstate > /sys/kernel/debug/tracing/current_tracer echo 1 > /sys/kernel/debug/tracing/tracing_enabled sleep 1 echo 0 > /sys/kernel/debug/tracing/tracing_enabled cat /sys/kernel/debug/tracing/trace | perl scripts/trace/cstate.pl > out.svg Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | ftrace: add thread comm to function graph tracerSteven Rostedt2008-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: enhancement to function graph tracer Export the trace_find_cmdline so the function graph tracer can use it to print the comms of the threads. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | tracing/function-return-tracer: set a more human readable outputFrederic Weisbecker2008-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: feature This patch sets a C-like output for the function graph tracing. For this aim, we now call two handler for each function: one on the entry and one other on return. This way we can draw a well-ordered call stack. The pid of the previous trace is loosely stored to be compared against the one of the current trace to see if there were a context switch. Without this little feature, the call tree would seem broken at some locations. We could use the sched_tracer to capture these sched_events but this way of processing is much more simpler. 2 spaces have been chosen for indentation to fit the screen while deep calls. The time of execution in nanosecs is printed just after closed braces, it seems more easy this way to find the corresponding function. If the time was printed as a first column, it would be not so easy to find the corresponding function if it is called on a deep depth. I plan to output the return value but on 32 bits CPU, the return value can be 32 or 64, and its difficult to guess on which case we are. I don't know what would be the better solution on X86-32: only print eax (low-part) or even edx (high-part). Actually it's thee same problem when a function return a 8 bits value, the high part of eax could contain junk values... Here is an example of trace: sys_read() { fget_light() { } 526 vfs_read() { rw_verify_area() { security_file_permission() { cap_file_permission() { } 519 } 1564 } 2640 do_sync_read() { pipe_read() { __might_sleep() { } 511 pipe_wait() { prepare_to_wait() { } 760 deactivate_task() { dequeue_task() { dequeue_task_fair() { dequeue_entity() { update_curr() { update_min_vruntime() { } 504 } 1587 clear_buddies() { } 512 add_cfs_task_weight() { } 519 update_min_vruntime() { } 511 } 5602 dequeue_entity() { update_curr() { update_min_vruntime() { } 496 } 1631 clear_buddies() { } 496 update_min_vruntime() { } 527 } 4580 hrtick_update() { hrtick_start_fair() { } 488 } 1489 } 13700 } 14949 } 16016 msecs_to_jiffies() { } 496 put_prev_task_fair() { } 504 pick_next_task_fair() { } 489 pick_next_task_rt() { } 496 pick_next_task_fair() { } 489 pick_next_task_idle() { } 489 ------------8<---------- thread 4 ------------8<---------- finish_task_switch() { } 1203 do_softirq() { __do_softirq() { __local_bh_disable() { } 669 rcu_process_callbacks() { __rcu_process_callbacks() { cpu_quiet() { rcu_start_batch() { } 503 } 1647 } 3128 __rcu_process_callbacks() { } 542 } 5362 _local_bh_enable() { } 587 } 8880 } 9986 kthread_should_stop() { } 669 deactivate_task() { dequeue_task() { dequeue_task_fair() { dequeue_entity() { update_curr() { calc_delta_mine() { } 511 update_min_vruntime() { } 511 } 2813 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | tracing/function-return-tracer: change the name into function-graph-tracerFrederic Weisbecker2008-11-25
|/ / | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup This patch changes the name of the "return function tracer" into function-graph-tracer which is a more suitable name for a tracing which makes one able to retrieve the ordered call stack during the code flow. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86, bts, ftrace: a BTS ftrace plug-in prototypeMarkus Metzger2008-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add new ftrace plugin A prototype for a BTS ftrace plug-in. The tracer collects branch trace in a cyclic buffer for each cpu. The tracer is not configurable and the trace for each snapshot is appended when doing cat /debug/tracing/trace. This is a proof of concept that will be extended with future patches to become a (hopefully) useful tool. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86, ftrace: call trace->open() before stopping tracing; add ↵Markus Metzger2008-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | | trace->print_header() Add a callback to allow an ftrace plug-in to write its own header. Move the call to trace->open() up a few lines. The changes are required by the BTS ftrace plug-in. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing: identify which executable object the userspace address belongs toTörök Edwin2008-11-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: modify+improve the userstacktrace tracing visualization feature Store thread group leader id, and use it to lookup the address in the process's map. We could have looked up the address on thread's map, but the thread might not exist by the time we are called. The process might not exist either, but if you are reading trace_pipe, that is unlikely. Example usage: mount -t debugfs nodev /sys/kernel/debug cd /sys/kernel/debug/tracing echo userstacktrace >iter_ctrl echo sym-userobj >iter_ctrl echo sched_switch >current_tracer echo 1 >tracing_enabled cat trace_pipe >/tmp/trace& .... run application ... echo 0 >tracing_enabled cat /tmp/trace You'll see stack entries like: /lib/libpthread-2.7.so[+0xd370] You can convert them to function/line using: addr2line -fie /lib/libpthread-2.7.so 0xd370 Or: addr2line -fie /usr/lib/debug/libpthread-2.7.so 0xd370 For non-PIC/PIE executables this won't work: a.out[+0x73b] You need to run the following: addr2line -fie a.out 0x40073b (where 0x400000 is the default load address of a.out) Signed-off-by: Török Edwin <edwintorok@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing: add support for userspace stacktraces in tracing/iter_ctrlTörök Edwin2008-11-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add new (default-off) tracing visualization feature Usage example: mount -t debugfs nodev /sys/kernel/debug cd /sys/kernel/debug/tracing echo userstacktrace >iter_ctrl echo sched_switch >current_tracer echo 1 >tracing_enabled .... run application ... echo 0 >tracing_enabled Then read one of 'trace','latency_trace','trace_pipe'. To get the best output you can compile your userspace programs with frame pointers (at least glibc + the app you are tracing). Signed-off-by: Török Edwin <edwintorok@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing/function-return-tracer: add the overrun fieldFrederic Weisbecker2008-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: help to find the better depth of trace We decided to arbitrary define the depth of function return trace as "20". Perhaps this is not enough. To help finding an optimal depth, we measure now the overrun: the number of functions that have been missed for the current thread. By default this is not displayed, we have to do set a particular flag on the return tracer: echo overrun > /debug/tracing/trace_options And the overrun will be printed on the right. As the trace shows below, the current 20 depth is not enough. update_wall_time+0x37f/0x8c0 -> update_xtime_cache (345 ns) (Overruns: 2838) update_wall_time+0x384/0x8c0 -> clocksource_get_next (1141 ns) (Overruns: 2838) do_timer+0x23/0x100 -> update_wall_time (3882 ns) (Overruns: 2838) tick_do_update_jiffies64+0xbf/0x160 -> do_timer (5339 ns) (Overruns: 2838) tick_sched_timer+0x6a/0xf0 -> tick_do_update_jiffies64 (7209 ns) (Overruns: 2838) vgacon_set_cursor_size+0x98/0x120 -> native_io_delay (2613 ns) (Overruns: 274) vgacon_cursor+0x16e/0x1d0 -> vgacon_set_cursor_size (33151 ns) (Overruns: 274) set_cursor+0x5f/0x80 -> vgacon_cursor (36432 ns) (Overruns: 274) con_flush_chars+0x34/0x40 -> set_cursor (38790 ns) (Overruns: 274) release_console_sem+0x1ec/0x230 -> up (721 ns) (Overruns: 274) release_console_sem+0x225/0x230 -> wake_up_klogd (316 ns) (Overruns: 274) con_flush_chars+0x39/0x40 -> release_console_sem (2996 ns) (Overruns: 274) con_write+0x22/0x30 -> con_flush_chars (46067 ns) (Overruns: 274) n_tty_write+0x1cc/0x360 -> con_write (292670 ns) (Overruns: 274) smp_apic_timer_interrupt+0x2a/0x90 -> native_apic_mem_write (330 ns) (Overruns: 274) irq_enter+0x17/0x70 -> idle_cpu (413 ns) (Overruns: 274) smp_apic_timer_interrupt+0x2f/0x90 -> irq_enter (1525 ns) (Overruns: 274) ktime_get_ts+0x40/0x70 -> getnstimeofday (465 ns) (Overruns: 274) ktime_get_ts+0x60/0x70 -> set_normalized_timespec (436 ns) (Overruns: 274) ktime_get+0x16/0x30 -> ktime_get_ts (2501 ns) (Overruns: 274) hrtimer_interrupt+0x77/0x1a0 -> ktime_get (3439 ns) (Overruns: 274) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing/ftrace: implement a set_flag callback for tracersFrederic Weisbecker2008-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: give a way to send specific messages to tracers The current implementation of tracing uses some flags to control the output of general tracers. But we have no way to implement custom flags handling for a specific tracer. This patch proposes a new callback for the struct tracer which called set_flag and a structure that represents a 32 bits variable flag. A tracer can implement a struct tracer_flags on which it puts the initial value of the flag integer. Than it can place a range of flags with their name and their flag mask on the flag integer. The structure that implement a single flag is called struct tracer_opt. These custom flags will be available through the trace_options file like the general tracing flags. Changing their value is done like the other general flags. For example if you have a flag that calls "foo", you can activate it by writing "foo" or "nofoo" on trace_options. Note that the set_flag callback is optional and is only needed if you want the flags changing to be signaled to your tracer and let it to accept or refuse their assignment. V2: Some arrangements in coding style.... Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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*-. | Merge branches 'tracing/branch-tracer' and 'tracing/urgent' into tracing/coreIngo Molnar2008-11-18
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| * | tracing: branch tracer, fix writing to trace/trace_optionsAneesh Kumar K.V2008-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix trace_options behavior writing to trace/trace_options use the index of the array to find the value of the flag. With branch tracer flag defined conditionally, this breaks writing to trace_options with branch tracer disabled. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | tracing/ftrace: change the type of the init() callbackFrederic Weisbecker2008-11-16
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: extend the ->init() method with the ability to fail This bring a way to know if the initialization of a tracer successed. A tracer must return 0 on success and a traditional error (ie: -ENOMEM) if it fails. If a tracer fails to init, it is free to print a detailed warn. The tracing api will not and switch to a new tracer will just return the error from the init callback. Note: this will be used for the return tracer. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: CPU buffer start annotation clean upsSteven Rostedt2008-11-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: better handling of CPU buffer start annotation Because of the confusion with the per CPU buffers wrapping where one CPU might be more active at the end of the trace than the other CPUs causing that one CPU to have a shorter history. Kernel developers were confused by the "missing" data of that one CPU at the beginning of the trace output. An annotation was added to the trace output to show that the buffer had started: # tracer: function # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | ##### CPU 3 buffer started #### <idle>-0 [003] 158.192959: smp_apic_timer_interrupt [...] <idle>-0 [003] 161.556520: default_idle ##### CPU 1 buffer started #### <idle>-0 [001] 161.592494: hrtimer_force_reprogram [etc] But this annotation gets a bit messy when tracers do not fill the buffers. This patch does a couple of things: One) it adds a flag to trace_options to disable these annotations Two) it does not annotate if the tracer did not overflow its buffer. This makes the output much cleaner. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: add tracer called branchSteven Rostedt2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | Impact: added new branch tracer Currently the tracing of branch profiling (unlikelys and likelys hit) is only activated by the iter_ctrl. This patch adds a tracer called "branch" that will just trace the branch profiling. The advantage of adding this tracer is that it can be added to the ftrace selftests on startup. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: rename unlikely iter_ctrl to branchSteven Rostedt2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | Impact: rename of iter_ctrl unlikely to branch The unlikely name is ugly. This patch converts the iter_ctrl command "unlikely" and "nounlikely" to "branch" and "nobranch" respectively. It also renames a lot of internal functions to use "branch" instead of "unlikely". Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | trace: rename unlikely profiler to branch profilerSteven Rostedt2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | Impact: name change of unlikely tracer and profiler Ingo Molnar suggested changing the config from UNLIKELY_PROFILE to BRANCH_PROFILING. I never did like the "unlikely" name so I went one step farther, and renamed all the unlikely configurations to a "BRANCH" variant. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing: likely/unlikely branch annotation tracerSteven Rostedt2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: new likely/unlikely branch tracer This patch adds a way to record the instances of the likely() and unlikely() branch condition annotations. When "unlikely" is set in /debugfs/tracing/iter_ctrl the unlikely conditions will be added to any of the ftrace tracers. The change takes effect when a new tracer is passed into the current_tracer file. For example: bash-3471 [003] 357.014755: [INCORRECT] sched_info_dequeued:sched_stats.h:177 bash-3471 [003] 357.014756: [correct] update_curr:sched_fair.c:489 bash-3471 [003] 357.014758: [correct] calc_delta_fair:sched_fair.c:411 bash-3471 [003] 357.014759: [correct] account_group_exec_runtime:sched_stats.h:356 bash-3471 [003] 357.014761: [correct] update_curr:sched_fair.c:489 bash-3471 [003] 357.014763: [INCORRECT] calc_delta_fair:sched_fair.c:411 bash-3471 [003] 357.014765: [correct] calc_delta_mine:sched.c:1279 Which shows the normal tracer heading, as well as whether the condition was correct "[correct]" or was mistaken "[INCORRECT]", followed by the function, file name and line number. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing/fastboot: Use the ring-buffer timestamp for initcall entriesFrederic Weisbecker2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Split the boot tracer entries in two parts: call and return Now that we are using the sched tracer from the boot tracer, we want to use the same timestamp than the ring-buffer to have consistent time captures between sched events and initcall events. So we get rid of the old time capture by the boot tracer and split the initcall events in two parts: call and return. This way we have the ring buffer timestamp of both. An example trace: [ 27.904149584] calling net_ns_init+0x0/0x1c0 @ 1 [ 27.904429624] initcall net_ns_init+0x0/0x1c0 returned 0 after 0 msecs [ 27.904575926] calling reboot_init+0x0/0x20 @ 1 [ 27.904655399] initcall reboot_init+0x0/0x20 returned 0 after 0 msecs [ 27.904800228] calling sysctl_init+0x0/0x30 @ 1 [ 27.905142914] initcall sysctl_init+0x0/0x30 returned 0 after 0 msecs [ 27.905287211] calling ksysfs_init+0x0/0xb0 @ 1 ##### CPU 0 buffer started #### init-1 [000] 27.905395: 1:120:R + [001] 11:115:S ##### CPU 1 buffer started #### <idle>-0 [001] 27.905425: 0:140:R ==> [001] 11:115:R init-1 [000] 27.905426: 1:120:D ==> [000] 0:140:R <idle>-0 [000] 27.905431: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905451: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905456: 4:115:S ==> [000] 0:140:R udevd-11 [001] 27.905458: 11:115:R + [001] 14:115:R <idle>-0 [000] 27.905459: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905462: 0:140:R ==> [000] 4:115:R udevd-11 [001] 27.905462: 11:115:R ==> [001] 14:115:R ksoftirqd/0-4 [000] 27.905467: 4:115:S ==> [000] 0:140:R <idle>-0 [000] 27.905470: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905473: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905476: 4:115:S ==> [000] 0:140:R <idle>-0 [000] 27.905479: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905482: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905486: 4:115:S ==> [000] 0:140:R udevd-14 [001] 27.905499: 14:120:X ==> [001] 11:115:R udevd-11 [001] 27.905506: 11:115:R + [000] 1:120:D <idle>-0 [000] 27.905515: 0:140:R ==> [000] 1:120:R udevd-11 [001] 27.905517: 11:115:S ==> [001] 0:140:R [ 27.905557107] initcall ksysfs_init+0x0/0xb0 returned 0 after 3906 msecs [ 27.905705736] calling init_jiffies_clocksource+0x0/0x10 @ 1 [ 27.905779239] initcall init_jiffies_clocksource+0x0/0x10 returned 0 after 0 msecs [ 27.906769814] calling pm_init+0x0/0x30 @ 1 [ 27.906853627] initcall pm_init+0x0/0x30 returned 0 after 0 msecs [ 27.906997803] calling pm_disk_init+0x0/0x20 @ 1 [ 27.907076946] initcall pm_disk_init+0x0/0x20 returned 0 after 0 msecs [ 27.907222556] calling swsusp_header_init+0x0/0x30 @ 1 [ 27.907294325] initcall swsusp_header_init+0x0/0x30 returned 0 after 0 msecs [ 27.907439620] calling stop_machine_init+0x0/0x50 @ 1 init-1 [000] 27.907485: 1:120:R + [000] 2:115:S init-1 [000] 27.907490: 1:120:D ==> [000] 2:115:R kthreadd-2 [000] 27.907507: 2:115:R + [001] 15:115:R <idle>-0 [001] 27.907517: 0:140:R ==> [001] 15:115:R kthreadd-2 [000] 27.907517: 2:115:D ==> [000] 0:140:R <idle>-0 [000] 27.907521: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.907524: 0:140:R ==> [000] 4:115:R udevd-15 [001] 27.907527: 15:115:D + [000] 2:115:D ksoftirqd/0-4 [000] 27.907537: 4:115:S ==> [000] 2:115:R udevd-15 [001] 27.907537: 15:115:D ==> [001] 0:140:R kthreadd-2 [000] 27.907546: 2:115:R + [000] 1:120:D kthreadd-2 [000] 27.907550: 2:115:S ==> [000] 1:120:R init-1 [000] 27.907584: 1:120:R + [000] 15: 0:D init-1 [000] 27.907589: 1:120:R + [000] 2:115:S init-1 [000] 27.907593: 1:120:D ==> [000] 15: 0:R udevd-15 [000] 27.907601: 15: 0:S ==> [000] 2:115:R ##### CPU 0 buffer started #### kthreadd-2 [000] 27.907616: 2:115:R + [001] 16:115:R ##### CPU 1 buffer started #### <idle>-0 [001] 27.907620: 0:140:R ==> [001] 16:115:R kthreadd-2 [000] 27.907621: 2:115:D ==> [000] 0:140:R udevd-16 [001] 27.907625: 16:115:D + [000] 2:115:D <idle>-0 [000] 27.907628: 0:140:R + [000] 4:115:S udevd-16 [001] 27.907629: 16:115:D ==> [001] 0:140:R <idle>-0 [000] 27.907631: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.907636: 4:115:S ==> [000] 2:115:R kthreadd-2 [000] 27.907644: 2:115:R + [000] 1:120:D kthreadd-2 [000] 27.907647: 2:115:S ==> [000] 1:120:R init-1 [000] 27.907657: 1:120:R + [001] 16: 0:D <idle>-0 [001] 27.907666: 0:140:R ==> [001] 16: 0:R [ 27.907703862] initcall stop_machine_init+0x0/0x50 returned 0 after 0 msecs [ 27.907850704] calling filelock_init+0x0/0x30 @ 1 [ 27.907926573] initcall filelock_init+0x0/0x30 returned 0 after 0 msecs [ 27.908071327] calling init_script_binfmt+0x0/0x10 @ 1 [ 27.908165195] initcall init_script_binfmt+0x0/0x10 returned 0 after 0 msecs [ 27.908309461] calling init_elf_binfmt+0x0/0x10 @ 1 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing/fastboot: move boot tracer structs and funcs into their own header.Frederic Weisbecker2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | Impact: Cleanups on the boot tracer and ftrace This patch bring some cleanups about the boot tracer headers. The functions and structures of this tracer have nothing related to ftrace and should have so their own header file. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing: add a tracer to catch execution time of kernel functionsFrederic Weisbecker2008-11-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add new tracing plugin which can trace full (entry+exit) function calls This tracer uses the low level function return ftrace plugin to measure the execution time of the kernel functions. The first field is the caller of the function, the second is the measured function, and the last one is the execution time in nanoseconds. - v3: - HAVE_FUNCTION_RET_TRACER have been added. Each arch that support ftrace return should enable it. - ftrace_return_stub becomes ftrace_stub. - CONFIG_FUNCTION_RET_TRACER depends now on CONFIG_FUNCTION_TRACER - Return traces printing can be used for other tracers on trace.c - Adapt to the new tracing API (no more ctrl_update callback) - Correct the check of "disabled" during insertion. - Minor changes... Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: display start of CPU buffer in trace outputSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: change in trace output Because the trace buffers are per cpu ring buffers, the start of the trace can be confusing. If one CPU is very active at the end of the trace, its history will not go as far back as the other CPU traces. This means that output for a particular CPU may not appear for the first part of a trace. To help annotate what is happening, and to prevent any more confusion, this patch adds a line that annotates the start of a CPU buffer output. For example: automount-3495 [001] 184.596443: dnotify_parent <-vfs_write [...] automount-3495 [001] 184.596449: dput <-path_put automount-3496 [002] 184.596450: down_read_trylock <-do_page_fault [...] sshd-3497 [001] 184.597069: up_read <-do_page_fault <idle>-0 [000] 184.597074: __exit_idle <-exit_idle [...] automount-3496 [002] 184.597257: filemap_fault <-__do_fault <idle>-0 [003] 184.597261: exit_idle <-smp_apic_timer_interrupt Note, parsers of a trace output should always ignore any lines that start with a '#'. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: remove trace array ctrlSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | Impact: remove obsolete variable in trace_array structure With the new start / stop method of ftrace, the ctrl variable in the trace_array structure is now obsolete. Remove it. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: remove ctrl_update methodSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | Impact: Remove the ctrl_update tracer method With the new quick start/stop method of tracing, the ctrl_update method is out of date. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: fix sched_switch APISteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix for sched_switch that broke dynamic ftrace startup The commit: tracing/fastboot: use sched switch tracer from boot tracer broke the API of the sched_switch trace. The use of the tracing_start/stop_cmdline record is for only recording the cmdline, NOT recording the schedule switches themselves. Seeing that the boot tracer broke the API to do something that it wanted, this patch adds a new interface for the API while puting back the original interface of the old API. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: fix boot trace sched startupSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: boot tracer startup modified The boot tracer calls into some of the schedule tracing private functions that should not be exported. This patch cleans it up, and makes way for further changes in the ftrace infrastructure. This patch adds a api to assign a tracer array to the schedule context switch tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: restructure tracing start/stop infrastructureSteven Rostedt2008-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: change where tracing is started up and stopped Currently, when a new tracer is selected via echo'ing a tracer name into the current_tracer file, the startup is only done if tracing_enabled is set to one. If tracing_enabled is changed to zero (by echo'ing 0 into the tracing_enabled file) a full shutdown is performed. The full startup and shutdown of a tracer can be expensive and the user can lose out traces when echo'ing in 0 to the tracing_enabled file, because the process takes too long. There can also be places that the user would like to start and stop the tracer several times and doing the full startup and shutdown of a tracer might be too expensive. This patch performs the full startup and shutdown when a tracer is selected. It also adds a way to do a quick start or stop of a tracer. The quick version is just a flag that prevents the tracing from taking place, but the overhead of the code is still there. For example, the startup of a tracer may enable tracepoints, or enable the function tracer. The stop and start will just set a flag to have the tracer ignore the calls when the tracepoint or function trace is called. The overhead of the tracer may still be present when the tracer is stopped, but no tracing will occur. Setting the tracer to the 'nop' tracer (or any other tracer) will perform the shutdown of the tracer which will disable the tracepoint or disable the function tracer. The tracing_enabled file will simply start or stop tracing. This change is all internal. The end result for the user should be the same as before. If tracing_enabled is not set, no trace will happen. If tracing_enabled is set, then the trace will happen. The tracing_enabled variable is static between tracers. Enabling tracing_enabled and going to another tracer will keep tracing_enabled enabled. Same is true with disabling tracing_enabled. This patch will now provide a fast start/stop method to the users for enabling or disabling tracing. Note: There were two methods to the struct tracer that were never used: The methods start and stop. These were to be used as a hook to the reading of the trace output, but ended up not being necessary. These two methods are now used to enable the start and stop of each tracer, in case the tracer needs to do more than just not write into the buffer. For example, the irqsoff tracer must stop recording max latencies when tracing is stopped. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'tracing/fastboot' into tracing/ftraceIngo Molnar2008-11-06
|\ \
| * | tracing/fastboot: use sched switch tracer from boot tracerFrederic Weisbecker2008-11-04
| |/ | | | | | | | | | | | | | | | | | | | | | | | | Impact: enhance boot trace output with scheduling events Use the sched_switch tracer from the boot tracer. We also can trace schedule events inside the initcalls. Sched tracing is disabled after the initcall has finished and then reenabled before the next one is started. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: function tracer with irqs disabledSteven Rostedt2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: disable interrupts during trace entry creation (as opposed to preempt) To help with performance, I set the ftracer to not disable interrupts, and only to disable preemption. If an interrupt occurred, it would not be traced, because the function tracer protects itself from recursion. This may be faster, but the trace output might miss some traces. This patch makes the fuction trace disable interrupts, but it also adds a runtime feature to disable preemption instead. It does this by having two different tracer functions. When the function tracer is enabled, it will check to see which version is requested (irqs disabled or preemption disabled). Then it will use the corresponding function as the tracer. Irq disabling is the default behaviour, but if the user wants better performance, with the chance of missing traces, then they can choose the preempt disabled version. Running hackbench 3 times with the irqs disabled and 3 times with the preempt disabled function tracer yielded: tracing type times entries recorded ------------ -------- ---------------- irq disabled 43.393 166433066 43.282 166172618 43.298 166256704 preempt disabled 38.969 159871710 38.943 159972935 39.325 161056510 Average: irqs disabled: 43.324 166287462 preempt disabled: 39.079 160300385 preempt is 10.8 percent faster than irqs disabled. I wrote a patch to count function trace recursion and reran hackbench. With irq disabled: 1,150 times the function tracer did not trace due to recursion. with preempt disabled: 5,117,718 times. The thousand times with irq disabled could be due to NMIs, or simply a case where it called a function that was not protected by notrace. But we also see that a large amount of the trace is lost with the preempt version. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | ftrace: introduce ftrace_preempt_disable()/enable()Steven Rostedt2008-11-04
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add new ftrace-plugin internal APIs Parts of the tracer needs to be careful about schedule recursion. If the NEED_RESCHED flag is set, a preempt_enable will call schedule. Inside the schedule function, the NEED_RESCHED flag is cleared. The problem arises when a trace happens in the schedule function but before NEED_RESCHED is cleared. The race is as follows: schedule() >> tracer called trace_function() preempt_disable() [ record trace ] preempt_enable() <<- here's the issue. [check NEED_RESCHED] schedule() [ Repeat the above, over and over again ] The naive approach is simply to use preempt_enable_no_schedule instead. The problem with that approach is that, although we solve the schedule recursion issue, we now might lose a preemption check when not in the schedule function. trace_function() preempt_disable() [ record trace ] [Interrupt comes in and sets NEED_RESCHED] preempt_enable_no_resched() [continue without scheduling] The way ftrace handles this problem is with the following approach: int resched; resched = need_resched(); preempt_disable_notrace(); [record trace] if (resched) preempt_enable_no_sched_notrace(); else preempt_enable_notrace(); This may seem like the opposite of what we want. If resched is set then we call the "no_sched" version?? The reason we do this is because if NEED_RESCHED is set before we disable preemption, there's two reasons for that: 1) we are in an atomic code path 2) we are already on our way to the schedule function, and maybe even in the schedule function, but have yet to clear the flag. Both the above cases we do not want to schedule. This solution has already been implemented within the ftrace infrastructure. But the problem is that it has been implemented several times. This patch encapsulates this code to two nice functions. resched = ftrace_preempt_disable(); [ record trace] ftrace_preempt_enable(resched); This way the tracers do not need to worry about getting it right. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: handle archs that do not support irqs_disabled_flagsSteven Rostedt2008-10-30
| | | | | | | | | | | | | | | | | | | | | | Impact: build fix on non-lockdep architectures Some architectures do not support a way to read the irq flags that is set from "local_irq_save(flags)" to determine if interrupts were disabled or enabled. Ftrace uses this information to display to the user if the trace occurred with interrupts enabled or disabled. Besides the fact that those archs that do not support this will fail to compile, unless they fix it, we do not want to have the trace simply say interrupts were not disabled or they were enabled, without knowing the real answer. This patch adds a 'X' in the output to let the user know that the architecture they are running on does not support a way for the tracer to determine if interrupts were enabled or disabled. It also lets those same archs compile with tracing enabled. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: rename FTRACE to FUNCTION_TRACERSteven Rostedt2008-10-20
| | | | | | | | | | | | Due to confusion between the ftrace infrastructure and the gcc profiling tracer "ftrace", this patch renames the config options from FTRACE to FUNCTION_TRACER. The other two names that are offspring from FTRACE DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same. This patch was generated mostly by script, and partially by hand. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: preempt disable over interrupt disableSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the new ring buffer infrastructure in ftrace, I'm trying to make ftrace a little more light weight. This patch converts a lot of the local_irq_save/restore into preempt_disable/enable. The original preempt count in a lot of cases has to be sent in as a parameter so that it can be recorded correctly. Some places were recording it incorrectly before anyway. This is also laying the ground work to make ftrace a little bit more reentrant, and remove all locking. The function tracers must still protect from reentrancy. Note: All the function tracers must be careful when using preempt_disable. It must do the following: resched = need_resched(); preempt_disable_notrace(); [...] if (resched) preempt_enable_no_resched_notrace(); else preempt_enable_notrace(); The reason is that if this function traces schedule() itself, the preempt_enable_notrace() will cause a schedule, which will lead us into a recursive failure. If we needed to reschedule before calling preempt_disable, we should have already scheduled. Since we did not, this is most likely that we should not and are probably inside a schedule function. If resched was not set, we still need to catch the need resched flag being set when preemption was off and the if case at the end will catch that for us. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: type cast filter+verifierSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | | | The mmiotrace map had a bug that would typecast the entry from the trace to the wrong type. That is a known danger of C typecasts, there's absolutely zero checking done on them. Help that problem a bit by using a GCC extension to implement a type filter that restricts the types that a trace record can be cast into, and by adding a dynamic check (in debug mode) to verify the type of the entry. This patch adds a macro to assign all entries of ftrace using the type of the variable and checking the entry id. The typecasts are now done in the macro for only those types that it knows about, which should be all the types that are allowed to be read from the tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: change the type of the print_line callbackFrederic Weisbecker2008-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | We need a kind of disambiguation when a print_line callback returns 0. _There is not enough space to print all the entry. Please flush the seq and retry. _I can't handle this type of entry This patch changes the type of this callback for better information. Also some changes have been made in this V2. _ Only relay to default functions after the print_line callback fails. _ This patch doesn't fix the issue with the broken pipe (see patch 2/4 for that) Some things are still in discussion: _ Find better names for the enum print_line_t values _ Change the type of print_trace_line into boolean. Patches to change that can be sent later. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: take advantage of variable length entriesSteven Rostedt2008-10-14
| | | | | | | | | | | | | | Now that the underlining ring buffer for ftrace now hold variable length entries, we can take advantage of this by only storing the size of the actual event into the buffer. This happens to increase the number of entries in the buffer dramatically. We can also get rid of the "trace_cont" operation, but I'm keeping that until we have no more users. Some of the ftrace tracers can now change their code to adapt to this new feature. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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