| Age | Commit message (Collapse) | Author | Files | Lines |
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Impact: build fix
The 'struct power_trace' definition is needed (for the event tracer) even if
the power-tracer plugin is turned off in the .config.
Cc: Steven Rostedt <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Augment the traces with lock names when lockdep is available:
1) | down_read_trylock() {
1) | _spin_lock_irqsave() {
1) | /* lock_acquire: &sem->wait_lock */
1) 4.201 us | }
1) | _spin_unlock_irqrestore() {
1) | /* lock_release: &sem->wait_lock */
1) 3.523 us | }
1) | /* lock_acquire: try read &mm->mmap_sem */
1) + 13.386 us | }
1) 1.635 us | find_vma();
1) | handle_mm_fault() {
1) | __do_fault() {
1) | filemap_fault() {
1) | find_lock_page() {
1) | find_get_page() {
1) | /* lock_acquire: read rcu_read_lock */
1) | /* lock_release: rcu_read_lock */
1) 5.697 us | }
1) 8.158 us | }
1) + 11.079 us | }
1) | _spin_lock() {
1) | /* lock_acquire: __pte_lockptr(page) */
1) 3.949 us | }
1) 1.460 us | page_add_file_rmap();
1) | _spin_unlock() {
1) | /* lock_release: __pte_lockptr(page) */
1) 3.115 us | }
1) | unlock_page() {
1) 1.421 us | page_waitqueue();
1) 1.220 us | __wake_up_bit();
1) 6.519 us | }
1) + 34.328 us | }
1) + 37.452 us | }
1) | up_read() {
1) | /* lock_release: &mm->mmap_sem */
1) | _spin_lock_irqsave() {
1) | /* lock_acquire: &sem->wait_lock */
1) 3.865 us | }
1) | _spin_unlock_irqrestore() {
1) | /* lock_release: &sem->wait_lock */
1) 8.562 us | }
1) + 17.370 us | }
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: =?ISO-8859-1?Q?T=F6r=F6k?= Edwin <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
LKML-Reference: <1236166375.5330.7209.camel@laptop>
Signed-off-by: Ingo Molnar <[email protected]>
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Tom Zanussi pointed out that the simple TRACE_FIELD was not enough to
record trace data that required memcpy. This patch addresses this issue
by adding a TRACE_FIELD_SPECIAL. The format is similar to TRACE_FIELD
but looks like so:
TRACE_FIELD_SPECIAL(type_item, item, cmd)
What TRACE_FIELD gave was:
TRACE_FIELD(type, item, assign)
The TRACE_FIELD would be used in declaring a structure:
struct {
type item;
};
And later assign it via:
entry->item = assign;
What TRACE_FIELD_SPECIAL gives us is:
In the declaration of the structure:
struct {
type_item;
};
And the assignment:
cmd;
This change log will explain the one example used in the patch:
TRACE_EVENT_FORMAT(sched_switch,
TPPROTO(struct rq *rq, struct task_struct *prev,
struct task_struct *next),
TPARGS(rq, prev, next),
TPFMT("task %s:%d ==> %s:%d",
prev->comm, prev->pid, next->comm, next->pid),
TRACE_STRUCT(
TRACE_FIELD(pid_t, prev_pid, prev->pid)
TRACE_FIELD(int, prev_prio, prev->prio)
TRACE_FIELD_SPECIAL(char next_comm[TASK_COMM_LEN],
next_comm,
TPCMD(memcpy(TRACE_ENTRY->next_comm,
next->comm,
TASK_COMM_LEN)))
TRACE_FIELD(pid_t, next_pid, next->pid)
TRACE_FIELD(int, next_prio, next->prio)
),
TPRAWFMT("prev %d:%d ==> next %s:%d:%d")
);
The struct will be create as:
struct {
pid_t prev_pid;
int prev_prio;
char next_comm[TASK_COMM_LEN];
pid_t next_pid;
int next_prio;
};
Note the TRACE_ENTRY in the cmd part of TRACE_SPECIAL. TRACE_ENTRY will
be set by the tracer to point to the structure inside the trace buffer.
entry->prev_pid = prev->pid;
entry->prev_prio = prev->prio;
memcpy(entry->next_comm, next->comm, TASK_COMM_LEN);
entry->next_pid = next->pid;
entry->next_prio = next->prio
Reported-by: Tom Zanussi <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
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This patch utilizes the TRACE_EVENT_FORMAT macro to enable the C style
faster tracing for the irq subsystem trace points.
Signed-off-by: Steven Rostedt <[email protected]>
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This patch utilizes the TRACE_EVENT_FORMAT macro to enable the C style
faster tracing for the sched subsystem trace points.
Signed-off-by: Steven Rostedt <[email protected]>
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Add the TRACE_SYSTEM sched for the sched events.
Signed-off-by: Steven Rostedt <[email protected]>
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Add the TRACE_SYSTEM irq for the irq events.
Signed-off-by: Steven Rostedt <[email protected]>
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Impact: clean up
To further facilitate the ease of adding trace points for developers, this
patch creates include/trace/trace_events.h and
include/trace/trace_event_types.h.
The former file will hold the trace/<type>.h files and the latter will hold
the trace/<type>_event_types.h files.
To create new tracepoints and to have them automatically
appear in the event tracer, a developer makes the trace/<type>.h file
which includes <linux/tracepoint.h> and the trace/<type>_event_types.h file.
The trace/<type>_event_types.h file will hold the TRACE_FORMAT
macros.
Then add the trace/<type>.h file to trace/trace_events.h,
and add the trace/<type>_event_types.h to the trace_event_types.h file.
No need to modify files elsewhere.
Signed-off-by: Steven Rostedt <[email protected]>
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Impact: add new tracepoints
Add them to the generic IRQ code, that way every architecture
gets these new tracepoints, not just x86.
Using Steve's new 'TRACE_FORMAT', I can get function graph
trace as follows using the original two IRQ tracepoints:
3) | handle_IRQ_event() {
3) | /* (irq_handler_entry) irq=28 handler=eth0 */
3) | e1000_intr_msi() {
3) 2.460 us | __napi_schedule();
3) 9.416 us | }
3) | /* (irq_handler_exit) irq=28 handler=eth0 return=handled */
3) + 22.935 us | }
Signed-off-by: Jason Baron <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: "Frank Ch. Eigler" <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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There's been a bit confusion to whether DEFINE/DECLARE_TRACE_FMT should
be a DEFINE or a DECLARE. Ingo Molnar suggested simply calling it
TRACE_FORMAT.
Reported-by: Ingo Molnar <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
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This patch changes the trace/sched.h to use the DECLARE_TRACE_FMT
such that they are automatically registered with the event tracer.
And it also adds the tracing sched headers to kernel/trace/events.c
Signed-off-by: Steven Rostedt <[email protected]>
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Convert the c/p state "power" tracer to use tracepoints. Avoids a
function call when the tracer is disabled.
Signed-off-by: Jason Baron <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
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Impact: cleanup
Move the power tracer headers to trace/power.h to keep ftrace.h and power bits
more easy to maintain as separated topics.
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Impact: new tracer
The workqueue tracer provides some statistical informations
about each cpu workqueue thread such as the number of the
works inserted and executed since their creation. It can help
to evaluate the amount of work each of them have to perform.
For example it can help a developer to decide whether he should
choose a per cpu workqueue instead of a singlethreaded one.
It only traces statistical informations for now but it will probably later
provide event tracing too.
Such a tracer could help too, and be improved, to help rt priority sorted
workqueue development.
To have a snapshot of the workqueues state at any time, just do
cat /debugfs/tracing/trace_stat/workqueues
Ie:
1 125 125 reiserfs/1
1 0 0 scsi_tgtd/1
1 0 0 aio/1
1 0 0 ata/1
1 114 114 kblockd/1
1 0 0 kintegrityd/1
1 2147 2147 events/1
0 0 0 kpsmoused
0 105 105 reiserfs/0
0 0 0 scsi_tgtd/0
0 0 0 aio/0
0 0 0 ata_aux
0 0 0 ata/0
0 0 0 cqueue
0 0 0 kacpi_notify
0 0 0 kacpid
0 149 149 kblockd/0
0 0 0 kintegrityd/0
0 1000 1000 khelper
0 2270 2270 events/0
Changes in V2:
_ Drop the static array based on NR_CPU and dynamically allocate the stat array
with num_possible_cpus() and other cpu mask facilities....
_ Trace workqueue insertion at a bit lower level (insert_work instead of queue_work) to handle
even the workqueue barriers.
Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Impact: new tracer plugin
This patch adapts kmemtrace raw events tracing to the unified tracing API.
To enable and use this tracer, just do the following:
echo kmemtrace > /debugfs/tracing/current_tracer
cat /debugfs/tracing/trace
You will have the following output:
# tracer: kmemtrace
#
#
# ALLOC TYPE REQ GIVEN FLAGS POINTER NODE CALLER
# FREE | | | | | | | |
# |
type_id 1 call_site 18446744071565527833 ptr 18446612134395152256
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345164672 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345164912 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345165152 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 0 call_site 18446744071566144042 ptr 18446612134346191680 bytes_req 1304 bytes_alloc 1312 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
That was to stay backward compatible with the format output produced in
inux/tracepoint.h.
This is the default ouput, but note that I tried something else.
If you change an option:
echo kmem_minimalistic > /debugfs/trace_options
and then cat /debugfs/trace, you will have the following output:
# tracer: kmemtrace
#
#
# ALLOC TYPE REQ GIVEN FLAGS POINTER NODE CALLER
# FREE | | | | | | | |
# |
- C 0xffff88007c088780 file_free_rcu
+ K 4096 4096 000000d0 0xffff88007cad6000 -1 getname
- C 0xffff88007cad6000 putname
+ K 4096 4096 000000d0 0xffff88007cad6000 -1 getname
+ K 240 240 000000d0 0xffff8800790dc780 -1 d_alloc
- C 0xffff88007cad6000 putname
+ K 4096 4096 000000d0 0xffff88007cad6000 -1 getname
+ K 240 240 000000d0 0xffff8800790dc870 -1 d_alloc
- C 0xffff88007cad6000 putname
+ K 4096 4096 000000d0 0xffff88007cad6000 -1 getname
+ K 240 240 000000d0 0xffff8800790dc960 -1 d_alloc
+ K 1304 1312 000000d0 0xffff8800791d7340 -1 reiserfs_alloc_inode
- C 0xffff88007cad6000 putname
+ K 4096 4096 000000d0 0xffff88007cad6000 -1 getname
- C 0xffff88007cad6000 putname
+ K 992 1000 000000d0 0xffff880079045b58 -1 alloc_inode
+ K 768 1024 000080d0 0xffff88007c096400 -1 alloc_pipe_info
+ K 240 240 000000d0 0xffff8800790dca50 -1 d_alloc
+ K 272 320 000080d0 0xffff88007c088780 -1 get_empty_filp
+ K 272 320 000080d0 0xffff88007c088000 -1 get_empty_filp
Yeah I shall confess kmem_minimalistic should be: kmem_alternative.
Whatever, I find it more readable but this a personal opinion of course.
We can drop it if you want.
On the ALLOC/FREE column, + means an allocation and - a free.
On the type column, you have K = kmalloc, C = cache, P = page
I would like the flags to be GFP_* strings but that would not be easy to not
break the column with strings....
About the node...it seems to always be -1. I don't know why but that shouldn't
be difficult to find.
I moved linux/tracepoint.h to trace/tracepoint.h as well. I think that would
be more easy to find the tracer headers if they are all in their common
directory.
Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Impact: extend the wakeup tracepoint with the info whether the wakeup was real
Add the information needed to distinguish 'real' wakeups from 'false'
wakeups.
Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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these warnings:
kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_register’:
kernel/trace/trace_sched_switch.c:96: warning: passing argument 1 of ‘register_trace_sched_wakeup_new’ from incompatible pointer type
kernel/trace/trace_sched_switch.c:112: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type
kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_unregister’:
kernel/trace/trace_sched_switch.c:121: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type
Trigger because sched_wakeup_new tracepoints need the same trace
signature as sched_wakeup - which was changed recently.
Fix it.
Signed-off-by: Ingo Molnar <[email protected]>
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'tracing/function-graph-tracer' and 'tracing/hw-branch-tracing' into tracing/core
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The trace point only caught one of many places where a task changes cpu,
put it in the right place to we get all of them.
Change the signature while we're at it.
Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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For now include/trace/boot.h doesn't need to include necessary headers
for its functions and structures because the files that include it already
do it.
But boot.h could be needed as well for further uses on other files.
So, this patch adds the necessary headers for future purposes...
Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Impact: fix possible stack overrun
This is a port of a patch included in the mainline (KSYM_SYMBOL_LEN fixes).
The current func len is not large enough to contain the max symbol len, the
right size must be KSYM_SYMBOL_LEN.
Signed-off-by: Stephen Rothwell <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Port to the new tracepoints API: split DEFINE_TRACE() and DECLARE_TRACE()
sites. Spread them out to the usage sites, as suggested by
Mathieu Desnoyers.
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Mathieu Desnoyers <[email protected]>
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This was a forward port of work done by Mathieu Desnoyers, I changed it to
encode the 'what' parameter on the tracepoint name, so that one can register
interest in specific events and not on classes of events to then check the
'what' parameter.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Impact: API *CHANGE*. Must update all tracepoint users.
Add DEFINE_TRACE() to tracepoints to let them declare the tracepoint
structure in a single spot for all the kernel. It helps reducing memory
consumption, especially when declaring a lot of tracepoints, e.g. for
kmalloc tracing.
*API CHANGE WARNING*: now, DECLARE_TRACE() must be used in headers for
tracepoint declarations rather than DEFINE_TRACE(). This is the sane way
to do it. The name previously used was misleading.
Updates scheduler instrumentation to follow this API change.
Signed-off-by: Mathieu Desnoyers <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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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 <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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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 <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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make it a bit more structured hence more readable.
Signed-off-by: Ingo Molnar <[email protected]>
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Instrument the scheduler activity (sched_switch, migration, wakeups,
wait for a task, signal delivery) and process/thread
creation/destruction (fork, exit, kthread stop). Actually, kthread
creation is not instrumented in this patch because it is architecture
dependent. It allows to connect tracers such as ftrace which detects
scheduling latencies, good/bad scheduler decisions. Tools like LTTng can
export this scheduler information along with instrumentation of the rest
of the kernel activity to perform post-mortem analysis on the scheduler
activity.
About the performance impact of tracepoints (which is comparable to
markers), even without immediate values optimizations, tests done by
Hideo Aoki on ia64 show no regression. His test case was using hackbench
on a kernel where scheduler instrumentation (about 5 events in code
scheduler code) was added. See the "Tracepoints" patch header for
performance result detail.
Changelog :
- Change instrumentation location and parameter to match ftrace
instrumentation, previously done with kernel markers.
[ [email protected]: conflict resolutions ]
Signed-off-by: Mathieu Desnoyers <[email protected]>
Acked-by: 'Peter Zijlstra' <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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