debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.
Many developers use "/debug/" or "/debugfs/" or "/sys/kernel/debug/"
directory name to mount debugfs filesystem for ftrace according to
./Documentation/tracers/ftrace.txt file.
And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
existed in kernel source like ftrace, DRM, Wireless, Documentation,
Network[sky2]files to mount debugfs filesystem.
debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/sys/kernel/debug/" name is suitable as directory name
of debugfs filesystem.
- debugfs related reference: http://lwn.net/Articles/334546/
Fix inconsistency of directory name to mount debugfs filesystem.
* From Steven Rostedt
- find_debugfs() and tracing_files() in this patch.
Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
Acked-by : Inaky Perez-Gonzalez <inaky@linux.intel.com>
Reviewed-by : Steven Rostedt <rostedt@goodmis.org>
Reviewed-by : James Smart <james.smart@emulex.com>
CC: Jiri Kosina <trivial@kernel.org>
CC: David Airlie <airlied@linux.ie>
CC: Peter Osterlund <petero2@telia.com>
CC: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
CC: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
CC: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/Documentation/DocBook/debugobjects.tmpl b/Documentation/DocBook/debugobjects.tmpl
index 7f5f218..08ff908 100644
--- a/Documentation/DocBook/debugobjects.tmpl
+++ b/Documentation/DocBook/debugobjects.tmpl
@@ -106,7 +106,7 @@
number of errors are printk'ed including a full stack trace.
</para>
<para>
- The statistics are available via debugfs/debug_objects/stats.
+ The statistics are available via /sys/kernel/debug/debug_objects/stats.
They provide information about the number of warnings and the
number of successful fixups along with information about the
usage of the internal tracking objects and the state of the
diff --git a/Documentation/cdrom/packet-writing.txt b/Documentation/cdrom/packet-writing.txt
index cf1f812..1c40777 100644
--- a/Documentation/cdrom/packet-writing.txt
+++ b/Documentation/cdrom/packet-writing.txt
@@ -117,7 +117,7 @@
To read pktcdvd device infos in human readable form, do:
- # cat /debug/pktcdvd/pktcdvd[0-7]/info
+ # cat /sys/kernel/debug/pktcdvd/pktcdvd[0-7]/info
For a description of the debugfs interface look into the file:
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index 4bc374a..0793056 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -29,16 +29,16 @@
fault-inject-debugfs kernel module provides some debugfs entries for runtime
configuration of fault-injection capabilities.
-- /debug/fail*/probability:
+- /sys/kernel/debug/fail*/probability:
likelihood of failure injection, in percent.
Format: <percent>
Note that one-failure-per-hundred is a very high error rate
for some testcases. Consider setting probability=100 and configure
- /debug/fail*/interval for such testcases.
+ /sys/kernel/debug/fail*/interval for such testcases.
-- /debug/fail*/interval:
+- /sys/kernel/debug/fail*/interval:
specifies the interval between failures, for calls to
should_fail() that pass all the other tests.
@@ -46,18 +46,18 @@
Note that if you enable this, by setting interval>1, you will
probably want to set probability=100.
-- /debug/fail*/times:
+- /sys/kernel/debug/fail*/times:
specifies how many times failures may happen at most.
A value of -1 means "no limit".
-- /debug/fail*/space:
+- /sys/kernel/debug/fail*/space:
specifies an initial resource "budget", decremented by "size"
on each call to should_fail(,size). Failure injection is
suppressed until "space" reaches zero.
-- /debug/fail*/verbose
+- /sys/kernel/debug/fail*/verbose
Format: { 0 | 1 | 2 }
specifies the verbosity of the messages when failure is
@@ -65,17 +65,17 @@
log line per failure; '2' will print a call trace too -- useful
to debug the problems revealed by fault injection.
-- /debug/fail*/task-filter:
+- /sys/kernel/debug/fail*/task-filter:
Format: { 'Y' | 'N' }
A value of 'N' disables filtering by process (default).
Any positive value limits failures to only processes indicated by
/proc/<pid>/make-it-fail==1.
-- /debug/fail*/require-start:
-- /debug/fail*/require-end:
-- /debug/fail*/reject-start:
-- /debug/fail*/reject-end:
+- /sys/kernel/debug/fail*/require-start:
+- /sys/kernel/debug/fail*/require-end:
+- /sys/kernel/debug/fail*/reject-start:
+- /sys/kernel/debug/fail*/reject-end:
specifies the range of virtual addresses tested during
stacktrace walking. Failure is injected only if some caller
@@ -84,26 +84,26 @@
Default required range is [0,ULONG_MAX) (whole of virtual address space).
Default rejected range is [0,0).
-- /debug/fail*/stacktrace-depth:
+- /sys/kernel/debug/fail*/stacktrace-depth:
specifies the maximum stacktrace depth walked during search
for a caller within [require-start,require-end) OR
[reject-start,reject-end).
-- /debug/fail_page_alloc/ignore-gfp-highmem:
+- /sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem:
Format: { 'Y' | 'N' }
default is 'N', setting it to 'Y' won't inject failures into
highmem/user allocations.
-- /debug/failslab/ignore-gfp-wait:
-- /debug/fail_page_alloc/ignore-gfp-wait:
+- /sys/kernel/debug/failslab/ignore-gfp-wait:
+- /sys/kernel/debug/fail_page_alloc/ignore-gfp-wait:
Format: { 'Y' | 'N' }
default is 'N', setting it to 'Y' will inject failures
only into non-sleep allocations (GFP_ATOMIC allocations).
-- /debug/fail_page_alloc/min-order:
+- /sys/kernel/debug/fail_page_alloc/min-order:
specifies the minimum page allocation order to be injected
failures.
@@ -166,13 +166,13 @@
#!/bin/bash
FAILTYPE=failslab
-echo Y > /debug/$FAILTYPE/task-filter
-echo 10 > /debug/$FAILTYPE/probability
-echo 100 > /debug/$FAILTYPE/interval
-echo -1 > /debug/$FAILTYPE/times
-echo 0 > /debug/$FAILTYPE/space
-echo 2 > /debug/$FAILTYPE/verbose
-echo 1 > /debug/$FAILTYPE/ignore-gfp-wait
+echo Y > /sys/kernel/debug/$FAILTYPE/task-filter
+echo 10 > /sys/kernel/debug/$FAILTYPE/probability
+echo 100 > /sys/kernel/debug/$FAILTYPE/interval
+echo -1 > /sys/kernel/debug/$FAILTYPE/times
+echo 0 > /sys/kernel/debug/$FAILTYPE/space
+echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
+echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
faulty_system()
{
@@ -217,20 +217,20 @@
exit 1
fi
-cat /sys/module/$module/sections/.text > /debug/$FAILTYPE/require-start
-cat /sys/module/$module/sections/.data > /debug/$FAILTYPE/require-end
+cat /sys/module/$module/sections/.text > /sys/kernel/debug/$FAILTYPE/require-start
+cat /sys/module/$module/sections/.data > /sys/kernel/debug/$FAILTYPE/require-end
-echo N > /debug/$FAILTYPE/task-filter
-echo 10 > /debug/$FAILTYPE/probability
-echo 100 > /debug/$FAILTYPE/interval
-echo -1 > /debug/$FAILTYPE/times
-echo 0 > /debug/$FAILTYPE/space
-echo 2 > /debug/$FAILTYPE/verbose
-echo 1 > /debug/$FAILTYPE/ignore-gfp-wait
-echo 1 > /debug/$FAILTYPE/ignore-gfp-highmem
-echo 10 > /debug/$FAILTYPE/stacktrace-depth
+echo N > /sys/kernel/debug/$FAILTYPE/task-filter
+echo 10 > /sys/kernel/debug/$FAILTYPE/probability
+echo 100 > /sys/kernel/debug/$FAILTYPE/interval
+echo -1 > /sys/kernel/debug/$FAILTYPE/times
+echo 0 > /sys/kernel/debug/$FAILTYPE/space
+echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
+echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
+echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-highmem
+echo 10 > /sys/kernel/debug/$FAILTYPE/stacktrace-depth
-trap "echo 0 > /debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
+trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
echo "Injecting errors into the module $module... (interrupt to stop)"
sleep 1000000
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 1e7a769..053037a 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -507,9 +507,9 @@
Appendix A: The kprobes debugfs interface
With recent kernels (> 2.6.20) the list of registered kprobes is visible
-under the /debug/kprobes/ directory (assuming debugfs is mounted at /debug).
+under the /sys/kernel/debug/kprobes/ directory (assuming debugfs is mounted at //sys/kernel/debug).
-/debug/kprobes/list: Lists all registered probes on the system
+/sys/kernel/debug/kprobes/list: Lists all registered probes on the system
c015d71a k vfs_read+0x0
c011a316 j do_fork+0x0
@@ -525,7 +525,7 @@
such probes are marked with [GONE]. If the probe is temporarily disabled,
such probes are marked with [DISABLED].
-/debug/kprobes/enabled: Turn kprobes ON/OFF forcibly.
+/sys/kernel/debug/kprobes/enabled: Turn kprobes ON/OFF forcibly.
Provides a knob to globally and forcibly turn registered kprobes ON or OFF.
By default, all kprobes are enabled. By echoing "0" to this file, all
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index 7bd27f0..a39b3c7 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -7,7 +7,6 @@
(dual licensed under the GPL v2)
Reviewers: Elias Oltmanns, Randy Dunlap, Andrew Morton,
John Kacur, and David Teigland.
-
Written for: 2.6.28-rc2
Introduction
@@ -33,13 +32,26 @@
Ftrace uses the debugfs file system to hold the control files as
well as the files to display output.
-To mount the debugfs system:
+When debugfs is configured into the kernel (which selecting any ftrace
+option will do) the directory /sys/kernel/debug will be created. To mount
+this directory, you can add to your /etc/fstab file:
- # mkdir /debug
- # mount -t debugfs nodev /debug
+ debugfs /sys/kernel/debug debugfs defaults 0 0
-( Note: it is more common to mount at /sys/kernel/debug, but for
- simplicity this document will use /debug)
+Or you can mount it at run time with:
+
+ mount -t debugfs nodev /sys/kernel/debug
+
+For quicker access to that directory you may want to make a soft link to
+it:
+
+ ln -s /sys/kernel/debug /debug
+
+Any selected ftrace option will also create a directory called tracing
+within the debugfs. The rest of the document will assume that you are in
+the ftrace directory (cd /sys/kernel/debug/tracing) and will only concentrate
+on the files within that directory and not distract from the content with
+the extended "/sys/kernel/debug/tracing" path name.
That's it! (assuming that you have ftrace configured into your kernel)
@@ -389,18 +401,18 @@
The trace_options file is used to control what gets printed in
the trace output. To see what is available, simply cat the file:
- cat /debug/tracing/trace_options
+ cat trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \
noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj
To disable one of the options, echo in the option prepended with
"no".
- echo noprint-parent > /debug/tracing/trace_options
+ echo noprint-parent > trace_options
To enable an option, leave off the "no".
- echo sym-offset > /debug/tracing/trace_options
+ echo sym-offset > trace_options
Here are the available options:
@@ -476,11 +488,11 @@
This tracer simply records schedule switches. Here is an example
of how to use it.
- # echo sched_switch > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo sched_switch > current_tracer
+ # echo 1 > tracing_enabled
# sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: sched_switch
#
@@ -583,13 +595,13 @@
To reset the maximum, echo 0 into tracing_max_latency. Here is
an example:
- # echo irqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo irqsoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: irqsoff
#
irqsoff latency trace v1.1.5 on 2.6.26
@@ -690,13 +702,13 @@
which preemption was disabled. The control of preemptoff tracer
is much like the irqsoff tracer.
- # echo preemptoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: preemptoff
#
preemptoff latency trace v1.1.5 on 2.6.26-rc8
@@ -837,13 +849,13 @@
Again, using this trace is much like the irqsoff and preemptoff
tracers.
- # echo preemptirqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptirqsoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: preemptirqsoff
#
preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8
@@ -999,12 +1011,12 @@
Instead of performing an 'ls', we will run 'sleep 1' under
'chrt' which changes the priority of the task.
- # echo wakeup > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo wakeup > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# chrt -f 5 sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: wakeup
#
wakeup latency trace v1.1.5 on 2.6.26-rc8
@@ -1114,11 +1126,11 @@
ftrace_enabled is set; otherwise this tracer is a nop.
# sysctl kernel.ftrace_enabled=1
- # echo function > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo function > current_tracer
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1155,7 +1167,7 @@
[...]
int main(int argc, char *argv[]) {
[...]
- trace_fd = open("/debug/tracing/tracing_enabled", O_WRONLY);
+ trace_fd = open(tracing_file("tracing_enabled"), O_WRONLY);
[...]
if (condition_hit()) {
write(trace_fd, "0", 1);
@@ -1163,26 +1175,20 @@
[...]
}
-Note: Here we hard coded the path name. The debugfs mount is not
-guaranteed to be at /debug (and is more commonly at
-/sys/kernel/debug). For simple one time traces, the above is
-sufficent. For anything else, a search through /proc/mounts may
-be needed to find where the debugfs file-system is mounted.
-
Single thread tracing
---------------------
-By writing into /debug/tracing/set_ftrace_pid you can trace a
+By writing into set_ftrace_pid you can trace a
single thread. For example:
-# cat /debug/tracing/set_ftrace_pid
+# cat set_ftrace_pid
no pid
-# echo 3111 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/set_ftrace_pid
+# echo 3111 > set_ftrace_pid
+# cat set_ftrace_pid
3111
-# echo function > /debug/tracing/current_tracer
-# cat /debug/tracing/trace | head
+# echo function > current_tracer
+# cat trace | head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1193,8 +1199,8 @@
yum-updatesd-3111 [003] 1637.254683: lock_hrtimer_base <-hrtimer_try_to_cancel
yum-updatesd-3111 [003] 1637.254685: fget_light <-do_sys_poll
yum-updatesd-3111 [003] 1637.254686: pipe_poll <-do_sys_poll
-# echo -1 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/trace |head
+# echo -1 > set_ftrace_pid
+# cat trace |head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1216,6 +1222,51 @@
#include <fcntl.h>
#include <unistd.h>
+#define _STR(x) #x
+#define STR(x) _STR(x)
+#define MAX_PATH 256
+
+const char *find_debugfs(void)
+{
+ static char debugfs[MAX_PATH+1];
+ static int debugfs_found;
+ char type[100];
+ FILE *fp;
+
+ if (debugfs_found)
+ return debugfs;
+
+ if ((fp = fopen("/proc/mounts","r")) == NULL) {
+ perror("/proc/mounts");
+ return NULL;
+ }
+
+ while (fscanf(fp, "%*s %"
+ STR(MAX_PATH)
+ "s %99s %*s %*d %*d\n",
+ debugfs, type) == 2) {
+ if (strcmp(type, "debugfs") == 0)
+ break;
+ }
+ fclose(fp);
+
+ if (strcmp(type, "debugfs") != 0) {
+ fprintf(stderr, "debugfs not mounted");
+ return NULL;
+ }
+
+ debugfs_found = 1;
+
+ return debugfs;
+}
+
+const char *tracing_file(const char *file_name)
+{
+ static char trace_file[MAX_PATH+1];
+ snprintf(trace_file, MAX_PATH, "%s/%s", find_debugfs(), file_name);
+ return trace_file;
+}
+
int main (int argc, char **argv)
{
if (argc < 1)
@@ -1226,12 +1277,12 @@
char line[64];
int s;
- ffd = open("/debug/tracing/current_tracer", O_WRONLY);
+ ffd = open(tracing_file("current_tracer"), O_WRONLY);
if (ffd < 0)
exit(-1);
write(ffd, "nop", 3);
- fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
+ fd = open(tracing_file("set_ftrace_pid"), O_WRONLY);
s = sprintf(line, "%d\n", getpid());
write(fd, line, s);
@@ -1383,22 +1434,22 @@
tracing_cpu_mask file) or you might sometimes see unordered
function calls while cpu tracing switch.
- hide: echo nofuncgraph-cpu > /debug/tracing/trace_options
- show: echo funcgraph-cpu > /debug/tracing/trace_options
+ hide: echo nofuncgraph-cpu > trace_options
+ show: echo funcgraph-cpu > trace_options
- The duration (function's time of execution) is displayed on
the closing bracket line of a function or on the same line
than the current function in case of a leaf one. It is default
enabled.
- hide: echo nofuncgraph-duration > /debug/tracing/trace_options
- show: echo funcgraph-duration > /debug/tracing/trace_options
+ hide: echo nofuncgraph-duration > trace_options
+ show: echo funcgraph-duration > trace_options
- The overhead field precedes the duration field in case of
reached duration thresholds.
- hide: echo nofuncgraph-overhead > /debug/tracing/trace_options
- show: echo funcgraph-overhead > /debug/tracing/trace_options
+ hide: echo nofuncgraph-overhead > trace_options
+ show: echo funcgraph-overhead > trace_options
depends on: funcgraph-duration
ie:
@@ -1427,8 +1478,8 @@
- The task/pid field displays the thread cmdline and pid which
executed the function. It is default disabled.
- hide: echo nofuncgraph-proc > /debug/tracing/trace_options
- show: echo funcgraph-proc > /debug/tracing/trace_options
+ hide: echo nofuncgraph-proc > trace_options
+ show: echo funcgraph-proc > trace_options
ie:
@@ -1451,8 +1502,8 @@
system clock since it started. A snapshot of this time is
given on each entry/exit of functions
- hide: echo nofuncgraph-abstime > /debug/tracing/trace_options
- show: echo funcgraph-abstime > /debug/tracing/trace_options
+ hide: echo nofuncgraph-abstime > trace_options
+ show: echo funcgraph-abstime > trace_options
ie:
@@ -1549,7 +1600,7 @@
available_filter_functions
- # cat /debug/tracing/available_filter_functions
+ # cat available_filter_functions
put_prev_task_idle
kmem_cache_create
pick_next_task_rt
@@ -1561,12 +1612,12 @@
If I am only interested in sys_nanosleep and hrtimer_interrupt:
# echo sys_nanosleep hrtimer_interrupt \
- > /debug/tracing/set_ftrace_filter
- # echo ftrace > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ > set_ftrace_filter
+ # echo ftrace > current_tracer
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: ftrace
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1577,7 +1628,7 @@
To see which functions are being traced, you can cat the file:
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_interrupt
sys_nanosleep
@@ -1597,7 +1648,7 @@
otherwise the shell may expand the parameters into names
of files in the local directory.
- # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' > set_ftrace_filter
Produces:
@@ -1618,7 +1669,7 @@
Notice that we lost the sys_nanosleep.
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1644,17 +1695,17 @@
To clear out a filter so that all functions will be recorded
again:
- # echo > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo > set_ftrace_filter
+ # cat set_ftrace_filter
#
Again, now we want to append.
- # echo sys_nanosleep > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo sys_nanosleep > set_ftrace_filter
+ # cat set_ftrace_filter
sys_nanosleep
- # echo 'hrtimer_*' >> /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' >> set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1677,7 +1728,7 @@
The set_ftrace_notrace prevents those functions from being
traced.
- # echo '*preempt*' '*lock*' > /debug/tracing/set_ftrace_notrace
+ # echo '*preempt*' '*lock*' > set_ftrace_notrace
Produces:
@@ -1767,13 +1818,13 @@
trace_pipe is consumed. This means that subsequent reads will be
different. The trace is live.
- # echo function > /debug/tracing/current_tracer
- # cat /debug/tracing/trace_pipe > /tmp/trace.out &
+ # echo function > current_tracer
+ # cat trace_pipe > /tmp/trace.out &
[1] 4153
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1809,7 +1860,7 @@
CPU. To know the full size, multiply the number of possible CPUS
with the number of entries.
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
1408 (units kilobytes)
Note, to modify this, you must have tracing completely disabled.
@@ -1817,18 +1868,18 @@
current_tracer is not set to "nop", an EINVAL error will be
returned.
- # echo nop > /debug/tracing/current_tracer
- # echo 10000 > /debug/tracing/buffer_size_kb
- # cat /debug/tracing/buffer_size_kb
+ # echo nop > current_tracer
+ # echo 10000 > buffer_size_kb
+ # cat buffer_size_kb
10000 (units kilobytes)
The number of pages which will be allocated is limited to a
percentage of available memory. Allocating too much will produce
an error.
- # echo 1000000000000 > /debug/tracing/buffer_size_kb
+ # echo 1000000000000 > buffer_size_kb
-bash: echo: write error: Cannot allocate memory
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
85
-----------
diff --git a/Documentation/trace/mmiotrace.txt b/Documentation/trace/mmiotrace.txt
index 5731c67..162effb 100644
--- a/Documentation/trace/mmiotrace.txt
+++ b/Documentation/trace/mmiotrace.txt
@@ -32,41 +32,41 @@
Usage Quick Reference
---------------------
-$ mount -t debugfs debugfs /debug
-$ echo mmiotrace > /debug/tracing/current_tracer
-$ cat /debug/tracing/trace_pipe > mydump.txt &
+$ mount -t debugfs debugfs /sys/kernel/debug
+$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer
+$ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt &
Start X or whatever.
-$ echo "X is up" > /debug/tracing/trace_marker
-$ echo nop > /debug/tracing/current_tracer
+$ echo "X is up" > /sys/kernel/debug/tracing/trace_marker
+$ echo nop > /sys/kernel/debug/tracing/current_tracer
Check for lost events.
Usage
-----
-Make sure debugfs is mounted to /debug. If not, (requires root privileges)
-$ mount -t debugfs debugfs /debug
+Make sure debugfs is mounted to /sys/kernel/debug. If not, (requires root privileges)
+$ mount -t debugfs debugfs /sys/kernel/debug
Check that the driver you are about to trace is not loaded.
Activate mmiotrace (requires root privileges):
-$ echo mmiotrace > /debug/tracing/current_tracer
+$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer
Start storing the trace:
-$ cat /debug/tracing/trace_pipe > mydump.txt &
+$ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt &
The 'cat' process should stay running (sleeping) in the background.
Load the driver you want to trace and use it. Mmiotrace will only catch MMIO
accesses to areas that are ioremapped while mmiotrace is active.
During tracing you can place comments (markers) into the trace by
-$ echo "X is up" > /debug/tracing/trace_marker
+$ echo "X is up" > /sys/kernel/debug/tracing/trace_marker
This makes it easier to see which part of the (huge) trace corresponds to
which action. It is recommended to place descriptive markers about what you
do.
Shut down mmiotrace (requires root privileges):
-$ echo nop > /debug/tracing/current_tracer
+$ echo nop > /sys/kernel/debug/tracing/current_tracer
The 'cat' process exits. If it does not, kill it by issuing 'fg' command and
pressing ctrl+c.
@@ -78,10 +78,10 @@
events were lost, the trace is incomplete. You should enlarge the buffers and
try again. Buffers are enlarged by first seeing how large the current buffers
are:
-$ cat /debug/tracing/buffer_size_kb
+$ cat /sys/kernel/debug/tracing/buffer_size_kb
gives you a number. Approximately double this number and write it back, for
instance:
-$ echo 128000 > /debug/tracing/buffer_size_kb
+$ echo 128000 > /sys/kernel/debug/tracing/buffer_size_kb
Then start again from the top.
If you are doing a trace for a driver project, e.g. Nouveau, you should also