Provided by: trace-cmd_2.3.1-1_amd64 bug

NAME

       trace-cmd-report - show in ASCII a trace created by trace-cmd record

SYNOPSIS

       trace-cmd report [OPTIONS] [input-file]

DESCRIPTION

       The trace-cmd(1) report command will output a human readable report of a trace created by
       trace-cmd record.

OPTIONS

       -i input-file
           By default, trace-cmd report will read the file trace.dat. But the -i option open up
           the given input-file instead. Note, the input file may also be specified as the last
           item on the command line.

       -e
           This outputs the endianess of the file. trace-cmd report is smart enough to be able to
           read big endian files on little endian machines, and vise versa.

       -f
           This outputs the list of functions that have been recorded in the file.

       -P
           This outputs the list of "trace_printk()" data. The raw trace data points to static
           pointers in the kernel. This must be stored in the trace.dat file.

       -E
           This lists the possible events in the file (but this list is not necessarily the list
           of events in the file).

       --events
           This will list the event formats that are stored in the trace.dat file.

       --check-events
           This will parse the event format strings that are stored in the trace.dat file and
           return whether the formats can be parsed correctly. It will load plugins unless -N is
           specified.

       -t
           Print the full timestamp. The timestamps in the data file are usually recorded to the
           nanosecond. But the default display of the timestamp is only to the microsecond. To
           see the full timestamp, add the -t option.

       -F filter
           Add a filter to limit what events are displayed. The format of the filter is:

               <events> ':' <filter>
               <events> = SYSTEM'/'EVENT  | SYSTEM | EVENT | <events> ',' <events>
               <filter> = EVENT_FIELD <op> <value> | <filter> '&&' <filter> |
                          <filter> '||' <filter> | '(' <filter> ')' | '!' <filter>
               <op> = '==' | '!=' | '>=' | '<=' | '>' | '<' | '&' | '|' | '^' |
                      '+' | '-' | '*' | '/' | '%'
               <value> = NUM | STRING | EVENT_FIELD

           SYSTEM is the name of the system to filter on. If the EVENT is left out,
           then it applies to all events under the SYSTEM. If only one string is used
           without the '/' to deliminate between SYSTEM and EVENT, then the filter
           will be applied to all systems and events that match the given string.

           Whitespace is ignored, such that "sched:next_pid==123" is equivalent to
           "sched : next_pid == 123".

           STRING is defined with single or double quotes (single quote must end with
           single quote, and double with double). Whitespace within quotes are not
           ignored.

           The representation of a SYSTEM or EVENT may also be a regular expression
           as defined by 'regcomp(3)'.

           The EVENT_FIELD is the name of the field of an event that is being
           filtered. If the event does not contain the EVENT_FIELD, that part of the
           equation will be considered false.

               -F 'sched : bogus == 1 || common_pid == 2'

           The "bogus == 1" will always evaluate to FALSE because no event has a
           field called "bogus", but the "common_pid == 2" will still be evaluated
           since all events have the field "common_pid". Any "sched" event that was
           traced by the process with the PID of 2 will be shown.

           Note, the EVENT_FIELD is the field name as shown by an events format
           (as displayed with *--events*), and not what is found in the output.
           If the output shows "ID:foo" but the field that "foo" belongs to was
           called "name" in the event format, then "name" must be used in the filter.
           The same is true about values. If the value that is displayed is converted
           by to a string symbol, the filter checks the original value and not the
           value displayed. For example, to filter on all tasks that were in the
           running state at a context switch:

               -F 'sched/sched_switch : prev_state==0'

           Although the output displays 'R', having 'prev_stat=="R"' will not work.

           Note: You can also specify 'COMM' as an EVENT_FIELD. This will use the
           task name (or comm) of the record to compare. For example, to filter out
           all of the "trace-cmd" tasks:

               -F '.*:COMM != "trace-cmd"'

       -v
           This causes the following filters of -F to filter out the matching events.

               -v -F 'sched/sched_switch : prev_state == 0'

           Will not display any sched_switch events that have a prev_state of 0.
           Removing the *-v* will only print out those events.

       -T
           Test the filters of -F. After processing a filter string, the resulting filter will be
           displayed for each event. This is useful for using a filter for more than one event
           where a field may not exist in all events. Also it can be used to make sure there are
           no misspelled event field names, as they will simply be ignored.  -T is ignored if -F
           is not specified.

       -V
           Show the plugins that are loaded.

       -L
           This will not load system wide plugins. It loads "local only". That is what it finds
           in the ~/.trace-cmd/plugins directory.

       -N
           This will not load any plugins.

       -n event-re
           This will cause all events that match the option to ignore any registered handler (by
           the plugins) to print the event. The normal event will be printed instead. The
           event-re is a regular expression as defined by regcomp(3).

       -R
           This will show the events in "raw" format. That is, it will ignore the event’s print
           formatting and just print the contents of each field.

       -r event-re
           This will cause all events that match the option to print its raw fields. The event-re
           is a regular expression as defined by regcomp(3).

       -l
           This adds a "latency output" format. Information about interrupts being disabled, soft
           irq being disabled, the "need_resched" flag being set, preempt count, and big kernel
           lock are all being recorded with every event. But the default display does not show
           this information. This option will set display this information with 6 characters.
           When one of the fields is zero or N/A a '.\' is shown.

                 <idle>-0       0d.h1. 106467.859747: function:             ktime_get <-- tick_check_idle

           The 0d.h1. denotes this information. The first character is never a '.'
           and represents what CPU the trace was recorded on (CPU 0). The 'd' denotes
           that interrupts were disabled. The 'h' means that this was called inside
           an interrupt handler. The '1' is the preemption disabled (preempt_count)
           was set to one.  The two '.'s are "need_resched" flag and kernel lock
           counter.  If the "need_resched" flag is set, then that character would be a
           'N'.

       -w
           If both the sched_switch and sched_wakeup events are enabled, then this option will
           report the latency between the time the task was first woken, and the time it was
           scheduled in.

       -q
           Quiet non critical warnings.

       -O
           Pass options to the trace-cmd plugins that are loaded.

               -O plugin:var=value

               The 'plugin:' and '=value' are optional. Value may be left off for options
               that are boolean. If the 'plugin:' is left off, then any variable that matches
               in all plugins will be set.

               Example:  -O fgraph:tailprint

       --stat
           If the trace.dat file recorded the final stats (outputed at the end of record) the
           --stat option can be used to retrieve them.

EXAMPLES

       Using a trace.dat file that was created with:

               # trace-cmd record -p function -e all sleep 5

       The default report shows:

            # trace-cmd report
                  trace-cmd-16129 [002] 158126.498411: function: __mutex_unlock_slowpath <-- mutex_unlock
                  trace-cmd-16131 [000] 158126.498411: kmem_cache_alloc: call_site=811223c5 ptr=0xffff88003ecf2b40 bytes_req=272 bytes_alloc=320 gfp_flags=GFP_KERNEL|GFP_ZERO
                  trace-cmd-16130 [003] 158126.498411: function:             do_splice_to <-- sys_splice
                      sleep-16133 [001] 158126.498412: function: inotify_inode_queue_event <-- vfs_write
                  trace-cmd-16129 [002] 158126.498420: lock_release: 0xffff88003f1fa4f8 &sb->s_type->i_mutex_key
                  trace-cmd-16131 [000] 158126.498421: function: security_file_alloc <-- get_empty_filp
                      sleep-16133 [001] 158126.498422: function: __fsnotify_parent <-- vfs_write
                  trace-cmd-16130 [003] 158126.498422: function: rw_verify_area <-- do_splice_to
                  trace-cmd-16131 [000] 158126.498424: function: cap_file_alloc_security <-- security_file_alloc
                  trace-cmd-16129 [002] 158126.498425: function: syscall_trace_leave <-- int_check_syscall_exit_work
                      sleep-16133 [001] 158126.498426: function: inotify_dentry_parent_queue_event <-- vfs_write
                  trace-cmd-16130 [003] 158126.498426: function: security_file_permission <-- rw_verify_area
                  trace-cmd-16129 [002] 158126.498428: function: audit_syscall_exit <-- syscall_trace_leave
           [...]

       To see everything but the function traces:

            # trace-cmd report -v -F 'function'
                  trace-cmd-16131 [000] 158126.498411: kmem_cache_alloc: call_site=811223c5 ptr=0xffff88003ecf2b40 bytes_req=272 bytes_alloc=320 gfp_flags=GFP_KERNEL|GFP_ZERO
                  trace-cmd-16129 [002] 158126.498420: lock_release: 0xffff88003f1fa4f8 &sb->s_type->i_mutex_key
                  trace-cmd-16130 [003] 158126.498436: lock_acquire: 0xffffffff8166bf78 read all_cpu_access_lock
                  trace-cmd-16131 [000] 158126.498438: lock_acquire: 0xffff88003df5b520 read &fs->lock
                  trace-cmd-16129 [002] 158126.498446: kfree: call_site=810a7abb ptr=0x0
                  trace-cmd-16130 [003] 158126.498448: lock_acquire: 0xffff880002250a80 &per_cpu(cpu_access_lock, cpu)
                  trace-cmd-16129 [002] 158126.498450: sys_exit_splice:      0xfffffff5
                  trace-cmd-16131 [000] 158126.498454: lock_release: 0xffff88003df5b520 &fs->lock
                      sleep-16133 [001] 158126.498456: kfree: call_site=810a7abb ptr=0x0
                      sleep-16133 [001] 158126.498460: sys_exit_write:       0x1
                  trace-cmd-16130 [003] 158126.498462: kmalloc: call_site=810bf95b ptr=0xffff88003dedc040 bytes_req=24 bytes_alloc=32 gfp_flags=GFP_KERNEL|GFP_ZERO

       To see only the kmalloc calls that were greater than 1000 bytes:

            #trace-cmd report -F 'kmalloc: bytes_req > 1000'
                     <idle>-0     [000] 158128.126641: kmalloc: call_site=81330635 ptr=0xffff88003c2fd000 bytes_req=2096 bytes_alloc=4096 gfp_flags=GFP_ATOMIC

       To see wakeups and sched switches that left the previous task in the running state:

            # trace-cmd report -F 'sched: prev_state == 0 || (success == 1)'
                  trace-cmd-16132 [002] 158126.499951: sched_wakeup: comm=trace-cmd pid=16129 prio=120 success=1 target_cpu=002
                  trace-cmd-16132 [002] 158126.500401: sched_switch: prev_comm=trace-cmd prev_pid=16132 prev_prio=120 prev_state=R ==> next_comm=trace-cmd next_pid=16129 next_prio=120
                     <idle>-0     [003] 158126.500585: sched_wakeup: comm=trace-cmd pid=16130 prio=120 success=1 target_cpu=003
                     <idle>-0     [003] 158126.501241: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=trace-cmd next_pid=16130 next_prio=120
                  trace-cmd-16132 [000] 158126.502475: sched_wakeup: comm=trace-cmd pid=16131 prio=120 success=1 target_cpu=000
                  trace-cmd-16131 [002] 158126.506516: sched_wakeup: comm=trace-cmd pid=16129 prio=120 success=1 target_cpu=002
                     <idle>-0     [003] 158126.550110: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=trace-cmd next_pid=16130 next_prio=120
                  trace-cmd-16131 [003] 158126.570243: sched_wakeup: comm=trace-cmd pid=16129 prio=120 success=1 target_cpu=003
                  trace-cmd-16130 [002] 158126.618202: sched_switch: prev_comm=trace-cmd prev_pid=16130 prev_prio=120 prev_state=R ==> next_comm=yum-updatesd next_pid=3088 next_prio=1 20
                  trace-cmd-16129 [003] 158126.622379: sched_wakeup: comm=trace-cmd pid=16131 prio=120 success=1 target_cpu=003
                  trace-cmd-16129 [000] 158126.649287: sched_wakeup: comm=trace-cmd pid=16131 prio=120 success=1 target_cpu=000

       The above needs a little explanation. The filter specifies the "sched" subsystem, which
       includes both sched_switch and sched_wakeup events. Any event that does not have the
       format field "prev_state" or "success", will evaluate those expressions as FALSE, and will
       not produce a match. Using "||" will have the "prev_state" test happen for the
       "sched_switch" event and the "success" test happen for the "sched_wakeup" event.

             # trace-cmd report -w -F 'sched_switch, sched_wakeup.*'
           [...]
                  trace-cmd-16130 [003] 158131.580616: sched_wakeup: comm=trace-cmd pid=16131 prio=120 success=1 target_cpu=003
                  trace-cmd-16129 [000] 158131.581502: sched_switch: prev_comm=trace-cmd prev_pid=16129 prev_prio=120 prev_state=S ==> next_comm=trace-cmd next_pid=16131 next_prio=120 Latency: 885.901 usecs
                  trace-cmd-16131 [000] 158131.582414: sched_wakeup: comm=trace-cmd pid=16129 prio=120 success=1 target_cpu=000
                  trace-cmd-16132 [001] 158131.583219: sched_switch: prev_comm=trace-cmd prev_pid=16132 prev_prio=120 prev_state=S ==> next_comm=trace-cmd next_pid=16129 next_prio=120 Latency: 804.809 usecs
                      sleep-16133 [002] 158131.584121: sched_wakeup: comm=trace-cmd pid=16120 prio=120 success=1 target_cpu=002
                  trace-cmd-16129 [001] 158131.584128: sched_wakeup: comm=trace-cmd pid=16132 prio=120 success=1 target_cpu=001
                      sleep-16133 [002] 158131.584275: sched_switch: prev_comm=sleep prev_pid=16133 prev_prio=120 prev_state=R ==> next_comm=trace-cmd next_pid=16120 next_prio=120 Latency: 153.915 usecs
                  trace-cmd-16130 [003] 158131.585284: sched_switch: prev_comm=trace-cmd prev_pid=16130 prev_prio=120 prev_state=S ==> next_comm=trace-cmd next_pid=16132 next_prio=120 Latency: 1155.677 usecs

           Average wakeup latency: 26626.656 usecs

       The above trace produces the wakeup latencies of the tasks. The "sched_switch" event
       reports each individual latency after writing the event information. At the end of the
       report, the average wakeup latency is reported.

             # trace-cmd report -w -F 'sched_switch, sched_wakeup.*: prio < 100 || next_prio < 100'
                     <idle>-0     [003] 158131.516753: sched_wakeup: comm=ksoftirqd/3 pid=13 prio=49 success=1 target_cpu=003
                     <idle>-0     [003] 158131.516855: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=ksoftirqd/3 next_pid=13 next_prio=49 Latency: 101.244 usecs
                     <idle>-0     [003] 158131.533781: sched_wakeup: comm=ksoftirqd/3 pid=13 prio=49 success=1 target_cpu=003
                     <idle>-0     [003] 158131.533897: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=ksoftirqd/3 next_pid=13 next_prio=49 Latency: 115.608 usecs
                     <idle>-0     [003] 158131.569730: sched_wakeup: comm=ksoftirqd/3 pid=13 prio=49 success=1 target_cpu=003
                     <idle>-0     [003] 158131.569851: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=ksoftirqd/3 next_pid=13 next_prio=49 Latency: 121.024 usecs

           Average wakeup latency: 110.021 usecs

       The above version will only show the wakeups and context switches of Real Time tasks. The
       prio used inside the kernel starts at 0 for highest priority. That is prio 0 is equivalent
       to user space real time priority 99, and priority 98 is equivalent to user space real time
       priority 1. Prios less than 100 represent Real Time tasks.

SEE ALSO

       trace-cmd(1), trace-cmd-record(1), trace-cmd-start(1), trace-cmd-stop(1),
       trace-cmd-extract(1), trace-cmd-reset(1), trace-cmd-split(1), trace-cmd-list(1),
       trace-cmd-listen(1)

AUTHOR

       Written by Steven Rostedt, <rostedt@goodmis.org[1]>

RESOURCES

       git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git

COPYING

       Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted under the terms of
       the GNU Public License (GPL).

NOTES

        1. rostedt@goodmis.org
           mailto:rostedt@goodmis.org

                                            01/29/2014                        TRACE-CMD-REPORT(1)