aboutsummaryrefslogtreecommitdiff
path: root/Documentation/trace
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/trace')
-rw-r--r--Documentation/trace/events-power.txt2
-rw-r--r--Documentation/trace/events.txt2
-rw-r--r--Documentation/trace/ftrace-design.txt5
-rw-r--r--Documentation/trace/ftrace.txt26
-rw-r--r--Documentation/trace/postprocess/trace-vmscan-postprocess.pl14
-rw-r--r--Documentation/trace/ring-buffer-design.txt2
-rw-r--r--Documentation/trace/tracepoints.txt24
7 files changed, 56 insertions, 19 deletions
diff --git a/Documentation/trace/events-power.txt b/Documentation/trace/events-power.txt
index 3bd33b8dc7c..21d514ced21 100644
--- a/Documentation/trace/events-power.txt
+++ b/Documentation/trace/events-power.txt
@@ -92,5 +92,5 @@ dev_pm_qos_remove_request "device=%s type=%s new_value=%d"
The first parameter gives the device name which tries to add/update/remove
QoS requests.
-The second parameter gives the request type (e.g. "DEV_PM_QOS_LATENCY").
+The second parameter gives the request type (e.g. "DEV_PM_QOS_RESUME_LATENCY").
The third parameter is value to be added/updated/removed.
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index c94435df203..75d25a1d6e4 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -443,7 +443,7 @@ The following commands are supported:
The following command creates a snapshot every time a block request
queue is unplugged with a depth > 1. If you were tracing a set of
events or functions at the time, the snapshot trace buffer would
- capture those events when the trigger event occured:
+ capture those events when the trigger event occurred:
# echo 'snapshot if nr_rq > 1' > \
/sys/kernel/debug/tracing/events/block/block_unplug/trigger
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt
index 79fcafc7fd6..3f669b9e885 100644
--- a/Documentation/trace/ftrace-design.txt
+++ b/Documentation/trace/ftrace-design.txt
@@ -358,11 +358,8 @@ Every arch has an init callback function. If you need to do something early on
to initialize some state, this is the time to do that. Otherwise, this simple
function below should be sufficient for most people:
-int __init ftrace_dyn_arch_init(void *data)
+int __init ftrace_dyn_arch_init(void)
{
- /* return value is done indirectly via data */
- *(unsigned long *)data = 0;
-
return 0;
}
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index bd365988e8d..2479b2a0c77 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -2003,6 +2003,32 @@ want, depending on your needs.
360.774530 | 1) 0.594 us | __phys_addr();
+The function name is always displayed after the closing bracket
+for a function if the start of that function is not in the
+trace buffer.
+
+Display of the function name after the closing bracket may be
+enabled for functions whose start is in the trace buffer,
+allowing easier searching with grep for function durations.
+It is default disabled.
+
+ hide: echo nofuncgraph-tail > trace_options
+ show: echo funcgraph-tail > trace_options
+
+ Example with nofuncgraph-tail (default):
+ 0) | putname() {
+ 0) | kmem_cache_free() {
+ 0) 0.518 us | __phys_addr();
+ 0) 1.757 us | }
+ 0) 2.861 us | }
+
+ Example with funcgraph-tail:
+ 0) | putname() {
+ 0) | kmem_cache_free() {
+ 0) 0.518 us | __phys_addr();
+ 0) 1.757 us | } /* kmem_cache_free() */
+ 0) 2.861 us | } /* putname() */
+
You can put some comments on specific functions by using
trace_printk() For example, if you want to put a comment inside
the __might_sleep() function, you just have to include
diff --git a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
index 00e425faa2f..78c9a7b2b58 100644
--- a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
+++ b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
@@ -47,7 +47,6 @@ use constant HIGH_KSWAPD_REWAKEUP => 21;
use constant HIGH_NR_SCANNED => 22;
use constant HIGH_NR_TAKEN => 23;
use constant HIGH_NR_RECLAIMED => 24;
-use constant HIGH_NR_CONTIG_DIRTY => 25;
my %perprocesspid;
my %perprocess;
@@ -105,7 +104,7 @@ my $regex_direct_end_default = 'nr_reclaimed=([0-9]*)';
my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)';
my $regex_kswapd_sleep_default = 'nid=([0-9]*)';
my $regex_wakeup_kswapd_default = 'nid=([0-9]*) zid=([0-9]*) order=([0-9]*)';
-my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_taken=([0-9]*) contig_taken=([0-9]*) contig_dirty=([0-9]*) contig_failed=([0-9]*)';
+my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_taken=([0-9]*) file=([0-9]*)';
my $regex_lru_shrink_inactive_default = 'nid=([0-9]*) zid=([0-9]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) priority=([0-9]*) flags=([A-Z_|]*)';
my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_rotated=([0-9]*) priority=([0-9]*)';
my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)';
@@ -200,7 +199,7 @@ $regex_lru_isolate = generate_traceevent_regex(
$regex_lru_isolate_default,
"isolate_mode", "order",
"nr_requested", "nr_scanned", "nr_taken",
- "contig_taken", "contig_dirty", "contig_failed");
+ "file");
$regex_lru_shrink_inactive = generate_traceevent_regex(
"vmscan/mm_vmscan_lru_shrink_inactive",
$regex_lru_shrink_inactive_default,
@@ -375,7 +374,6 @@ EVENT_PROCESS:
}
my $isolate_mode = $1;
my $nr_scanned = $4;
- my $nr_contig_dirty = $7;
# To closer match vmstat scanning statistics, only count isolate_both
# and isolate_inactive as scanning. isolate_active is rotation
@@ -385,7 +383,6 @@ EVENT_PROCESS:
if ($isolate_mode != 2) {
$perprocesspid{$process_pid}->{HIGH_NR_SCANNED} += $nr_scanned;
}
- $perprocesspid{$process_pid}->{HIGH_NR_CONTIG_DIRTY} += $nr_contig_dirty;
} elsif ($tracepoint eq "mm_vmscan_lru_shrink_inactive") {
$details = $6;
if ($details !~ /$regex_lru_shrink_inactive/o) {
@@ -539,13 +536,6 @@ sub dump_stats {
}
}
}
- if ($stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY}) {
- print " ";
- my $count = $stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY};
- if ($count != 0) {
- print "contig-dirty=$count ";
- }
- }
print "\n";
}
diff --git a/Documentation/trace/ring-buffer-design.txt b/Documentation/trace/ring-buffer-design.txt
index 7d350b49658..ff747b6fa39 100644
--- a/Documentation/trace/ring-buffer-design.txt
+++ b/Documentation/trace/ring-buffer-design.txt
@@ -683,7 +683,7 @@ against nested writers.
cmpxchg(tail_page, temp_page, next_page)
The above will update the tail page if it is still pointing to the expected
-page. If this fails, a nested write pushed it forward, the the current write
+page. If this fails, a nested write pushed it forward, the current write
does not need to push it.
diff --git a/Documentation/trace/tracepoints.txt b/Documentation/trace/tracepoints.txt
index 6b018b53177..a3efac621c5 100644
--- a/Documentation/trace/tracepoints.txt
+++ b/Documentation/trace/tracepoints.txt
@@ -115,6 +115,30 @@ If the tracepoint has to be used in kernel modules, an
EXPORT_TRACEPOINT_SYMBOL_GPL() or EXPORT_TRACEPOINT_SYMBOL() can be
used to export the defined tracepoints.
+If you need to do a bit of work for a tracepoint parameter, and
+that work is only used for the tracepoint, that work can be encapsulated
+within an if statement with the following:
+
+ if (trace_foo_bar_enabled()) {
+ int i;
+ int tot = 0;
+
+ for (i = 0; i < count; i++)
+ tot += calculate_nuggets();
+
+ trace_foo_bar(tot);
+ }
+
+All trace_<tracepoint>() calls have a matching trace_<tracepoint>_enabled()
+function defined that returns true if the tracepoint is enabled and
+false otherwise. The trace_<tracepoint>() should always be within the
+block of the if (trace_<tracepoint>_enabled()) to prevent races between
+the tracepoint being enabled and the check being seen.
+
+The advantage of using the trace_<tracepoint>_enabled() is that it uses
+the static_key of the tracepoint to allow the if statement to be implemented
+with jump labels and avoid conditional branches.
+
Note: The convenience macro TRACE_EVENT provides an alternative way to
define tracepoints. Check http://lwn.net/Articles/379903,
http://lwn.net/Articles/381064 and http://lwn.net/Articles/383362