You may want to know where and how long a task is sleeping. A callchain
may be found in sched_switch and a time slice in stat_iowait, so I add
handler in perf inject for merging this events.

My code saves sched_switch event for each process and when it meets
stat_iowait, it reports the sched_switch event, because this event
contains a correct callchain. By another words it replaces all
stat_iowait events on proper sched_switch events.

I use the next sequence of commands for testing:

  perf record -e sched:sched_stat_sleep -e sched:sched_switch \
	      -e sched:sched_process_exit -g -o ~/perf.data.raw \
	      ~/test-program
  perf inject -v -s -i ~/perf.data.raw -o ~/perf.data
  perf report --stdio -i ~/perf.data
   100.00%	foo  [kernel.kallsyms]  [k] __schedule
               	|
                --- __schedule
                    schedule
                   |
                   |--79.75%-- schedule_hrtimeout_range_clock
                   |          schedule_hrtimeout_range
                   |          poll_schedule_timeout
                   |          do_select
                   |          core_sys_select
                   |          sys_select
                   |          system_call_fastpath
                   |          __select
                   |          __libc_start_main
                   |
                    --20.25%-- do_nanosleep
                              hrtimer_nanosleep
                              sys_nanosleep
                              system_call_fastpath
                              __GI___libc_nanosleep
                              __libc_start_main

 And here is test-program.c:

 #include<unistd.h>
 #include<time.h>
 #include<sys/select.h>

 int main()
 {
	struct timespec ts1;
	struct timeval tv1;
	int i;
	long s;

	for (i = 0; i <  10; i++) {
		ts1.tv_sec = 0;
		ts1.tv_nsec = 10000000;
		nanosleep(&ts1, NULL);

		tv1.tv_sec = 0;
		tv1.tv_usec = 40000;
		select(0, NULL, NULL, NULL,&tv1);
	}
	return 1;
 }
Signed-off-by: NAndrew Vagin <avagin@openvz.org>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344344165-369636-4-git-send-email-avagin@openvz.org
[ committer note: Made it use evsel->handler ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Before this patch "perf inject" can only handle data from pipe.

I want to use "perf inject" for reworking events. Look at my following patch.

v2: add information about new options in tools/perf/Documentation/
Signed-off-by: NAndrew Vagin <avagin@openvz.org>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344344165-369636-2-git-send-email-avagin@openvz.org
[ committer note: fixed it up to cope with 5852a445, 5ded57ac, 002439e8 & f62d3f0f ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

New commands need to have Documentation and be added to command-list.txt
so that they can appear when 'perf' is called withouth any subcommand:

[root@doppio linux-2.6-tip]# perf

 usage: perf [--version] [--help] COMMAND [ARGS]

 The most commonly used perf commands are:
   annotate        Read perf.data (created by perf record) and display annotated code
   archive         Create archive with object files with build-ids found in perf.data file
   bench           General framework for benchmark suites
   buildid-cache   Manage build-id cache.
   buildid-list    List the buildids in a perf.data file
   diff            Read two perf.data files and display the differential profile
   inject          Filter to augment the events stream with additional information
   kmem            Tool to trace/measure kernel memory(slab) properties
   kvm             Tool to trace/measure kvm guest os
   list            List all symbolic event types
   lock            Analyze lock events
   probe           Define new dynamic tracepoints
   record          Run a command and record its profile into perf.data
   report          Read perf.data (created by perf record) and display the profile
   sched           Tool to trace/measure scheduler properties (latencies)
   stat            Run a command and gather performance counter statistics
   test            Runs sanity tests.
   timechart       Tool to visualize total system behavior during a workload
   top             System profiling tool.
   trace           Read perf.data (created by perf record) and display trace output

 See 'perf help COMMAND' for more information on a specific command.

[root@doppio linux-2.6-tip]#

The new 'perf inject' command hadn't so it wasn't appearing on that list.

Also fix the long option, that should have no spaces in it, rename the faulty one
to be '--build-ids', instead of '--inject build-ids'.
Reported-by: NIngo Molnar <mingo@elte.hu>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>