aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/trace
diff options
context:
space:
mode:
authorDmitry Torokhov <dmitry.torokhov@gmail.com>2014-08-07 02:36:12 -0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2014-08-07 02:36:12 -0400
commit5e2aa2ed08e2e280121dc7cf5609c87d464f12ef (patch)
treeca7d7b1480285e3b617fecc5b41f0ce150a82c32 /Documentation/trace
parentf62d14a8072b9756db36ba394e2b267470a40240 (diff)
parentfc8104bc5a3f6f49d79f45f2706f79f77a9fb2ae (diff)
Merge branch 'next' into for-linus
Prepare first round of input updates for 3.17.
Diffstat (limited to 'Documentation/trace')
-rw-r--r--Documentation/trace/events.txt2
-rw-r--r--Documentation/trace/ftrace.txt26
-rw-r--r--Documentation/trace/postprocess/trace-vmscan-postprocess.pl14
-rw-r--r--Documentation/trace/tracepoints.txt24
4 files changed, 53 insertions, 13 deletions
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index c94435df2037..75d25a1d6e42 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -443,7 +443,7 @@ The following commands are supported:
443 The following command creates a snapshot every time a block request 443 The following command creates a snapshot every time a block request
444 queue is unplugged with a depth > 1. If you were tracing a set of 444 queue is unplugged with a depth > 1. If you were tracing a set of
445 events or functions at the time, the snapshot trace buffer would 445 events or functions at the time, the snapshot trace buffer would
446 capture those events when the trigger event occured: 446 capture those events when the trigger event occurred:
447 447
448 # echo 'snapshot if nr_rq > 1' > \ 448 # echo 'snapshot if nr_rq > 1' > \
449 /sys/kernel/debug/tracing/events/block/block_unplug/trigger 449 /sys/kernel/debug/tracing/events/block/block_unplug/trigger
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index bd365988e8d8..2479b2a0c77c 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -2003,6 +2003,32 @@ want, depending on your needs.
2003 360.774530 | 1) 0.594 us | __phys_addr(); 2003 360.774530 | 1) 0.594 us | __phys_addr();
2004 2004
2005 2005
2006The function name is always displayed after the closing bracket
2007for a function if the start of that function is not in the
2008trace buffer.
2009
2010Display of the function name after the closing bracket may be
2011enabled for functions whose start is in the trace buffer,
2012allowing easier searching with grep for function durations.
2013It is default disabled.
2014
2015 hide: echo nofuncgraph-tail > trace_options
2016 show: echo funcgraph-tail > trace_options
2017
2018 Example with nofuncgraph-tail (default):
2019 0) | putname() {
2020 0) | kmem_cache_free() {
2021 0) 0.518 us | __phys_addr();
2022 0) 1.757 us | }
2023 0) 2.861 us | }
2024
2025 Example with funcgraph-tail:
2026 0) | putname() {
2027 0) | kmem_cache_free() {
2028 0) 0.518 us | __phys_addr();
2029 0) 1.757 us | } /* kmem_cache_free() */
2030 0) 2.861 us | } /* putname() */
2031
2006You can put some comments on specific functions by using 2032You can put some comments on specific functions by using
2007trace_printk() For example, if you want to put a comment inside 2033trace_printk() For example, if you want to put a comment inside
2008the __might_sleep() function, you just have to include 2034the __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 00e425faa2fd..78c9a7b2b58f 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;
47use constant HIGH_NR_SCANNED => 22; 47use constant HIGH_NR_SCANNED => 22;
48use constant HIGH_NR_TAKEN => 23; 48use constant HIGH_NR_TAKEN => 23;
49use constant HIGH_NR_RECLAIMED => 24; 49use constant HIGH_NR_RECLAIMED => 24;
50use constant HIGH_NR_CONTIG_DIRTY => 25;
51 50
52my %perprocesspid; 51my %perprocesspid;
53my %perprocess; 52my %perprocess;
@@ -105,7 +104,7 @@ my $regex_direct_end_default = 'nr_reclaimed=([0-9]*)';
105my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)'; 104my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)';
106my $regex_kswapd_sleep_default = 'nid=([0-9]*)'; 105my $regex_kswapd_sleep_default = 'nid=([0-9]*)';
107my $regex_wakeup_kswapd_default = 'nid=([0-9]*) zid=([0-9]*) order=([0-9]*)'; 106my $regex_wakeup_kswapd_default = 'nid=([0-9]*) zid=([0-9]*) order=([0-9]*)';
108my $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]*)'; 107my $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]*)';
109my $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_|]*)'; 108my $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_|]*)';
110my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_rotated=([0-9]*) priority=([0-9]*)'; 109my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_rotated=([0-9]*) priority=([0-9]*)';
111my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)'; 110my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)';
@@ -200,7 +199,7 @@ $regex_lru_isolate = generate_traceevent_regex(
200 $regex_lru_isolate_default, 199 $regex_lru_isolate_default,
201 "isolate_mode", "order", 200 "isolate_mode", "order",
202 "nr_requested", "nr_scanned", "nr_taken", 201 "nr_requested", "nr_scanned", "nr_taken",
203 "contig_taken", "contig_dirty", "contig_failed"); 202 "file");
204$regex_lru_shrink_inactive = generate_traceevent_regex( 203$regex_lru_shrink_inactive = generate_traceevent_regex(
205 "vmscan/mm_vmscan_lru_shrink_inactive", 204 "vmscan/mm_vmscan_lru_shrink_inactive",
206 $regex_lru_shrink_inactive_default, 205 $regex_lru_shrink_inactive_default,
@@ -375,7 +374,6 @@ EVENT_PROCESS:
375 } 374 }
376 my $isolate_mode = $1; 375 my $isolate_mode = $1;
377 my $nr_scanned = $4; 376 my $nr_scanned = $4;
378 my $nr_contig_dirty = $7;
379 377
380 # To closer match vmstat scanning statistics, only count isolate_both 378 # To closer match vmstat scanning statistics, only count isolate_both
381 # and isolate_inactive as scanning. isolate_active is rotation 379 # and isolate_inactive as scanning. isolate_active is rotation
@@ -385,7 +383,6 @@ EVENT_PROCESS:
385 if ($isolate_mode != 2) { 383 if ($isolate_mode != 2) {
386 $perprocesspid{$process_pid}->{HIGH_NR_SCANNED} += $nr_scanned; 384 $perprocesspid{$process_pid}->{HIGH_NR_SCANNED} += $nr_scanned;
387 } 385 }
388 $perprocesspid{$process_pid}->{HIGH_NR_CONTIG_DIRTY} += $nr_contig_dirty;
389 } elsif ($tracepoint eq "mm_vmscan_lru_shrink_inactive") { 386 } elsif ($tracepoint eq "mm_vmscan_lru_shrink_inactive") {
390 $details = $6; 387 $details = $6;
391 if ($details !~ /$regex_lru_shrink_inactive/o) { 388 if ($details !~ /$regex_lru_shrink_inactive/o) {
@@ -539,13 +536,6 @@ sub dump_stats {
539 } 536 }
540 } 537 }
541 } 538 }
542 if ($stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY}) {
543 print " ";
544 my $count = $stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY};
545 if ($count != 0) {
546 print "contig-dirty=$count ";
547 }
548 }
549 539
550 print "\n"; 540 print "\n";
551 } 541 }
diff --git a/Documentation/trace/tracepoints.txt b/Documentation/trace/tracepoints.txt
index 6b018b53177a..a3efac621c5a 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
115EXPORT_TRACEPOINT_SYMBOL_GPL() or EXPORT_TRACEPOINT_SYMBOL() can be 115EXPORT_TRACEPOINT_SYMBOL_GPL() or EXPORT_TRACEPOINT_SYMBOL() can be
116used to export the defined tracepoints. 116used to export the defined tracepoints.
117 117
118If you need to do a bit of work for a tracepoint parameter, and
119that work is only used for the tracepoint, that work can be encapsulated
120within an if statement with the following:
121
122 if (trace_foo_bar_enabled()) {
123 int i;
124 int tot = 0;
125
126 for (i = 0; i < count; i++)
127 tot += calculate_nuggets();
128
129 trace_foo_bar(tot);
130 }
131
132All trace_<tracepoint>() calls have a matching trace_<tracepoint>_enabled()
133function defined that returns true if the tracepoint is enabled and
134false otherwise. The trace_<tracepoint>() should always be within the
135block of the if (trace_<tracepoint>_enabled()) to prevent races between
136the tracepoint being enabled and the check being seen.
137
138The advantage of using the trace_<tracepoint>_enabled() is that it uses
139the static_key of the tracepoint to allow the if statement to be implemented
140with jump labels and avoid conditional branches.
141
118Note: The convenience macro TRACE_EVENT provides an alternative way to 142Note: The convenience macro TRACE_EVENT provides an alternative way to
119 define tracepoints. Check http://lwn.net/Articles/379903, 143 define tracepoints. Check http://lwn.net/Articles/379903,
120 http://lwn.net/Articles/381064 and http://lwn.net/Articles/383362 144 http://lwn.net/Articles/381064 and http://lwn.net/Articles/383362