diff options
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/events.txt | 2 | ||||
| -rw-r--r-- | Documentation/trace/ftrace.txt | 26 | ||||
| -rw-r--r-- | Documentation/trace/postprocess/trace-vmscan-postprocess.pl | 14 | ||||
| -rw-r--r-- | Documentation/trace/tracepoints.txt | 24 |
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: 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.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. 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 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; 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/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 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 |