[CRIU] [PATCH] [RFC] perf: Here is an example how to trace syscalls

[Pavel Emelyanov]

On 09/30/2014 04:05 PM, Andrey Vagin wrote:
> perf doesn't affect performance so significant as strace and
> it allows to trace parasite code.
> 
> All processes are executed in a new perf_evets cgroup and
> "perf record" collects events only for processes from this group.

Presumably I need to do some preparations:

Execute zdtm/live/static/env00
./env00 --pidfile=env00.pid --outfile=env00.out --envname=ENV_00_TEST
Dump 22781
no access to cgroup /sys/fs/cgroup/perf_event/test

 usage: perf record [<options>] [<command>]
    or: perf record [<options>] -- <command> [<options>]

    -G, --cgroup <name>   monitor event in cgroup name only
Use the following command to analize perf data:
perf trace report -i /root/src/criu/test/dump/static/env00/22781/1/perf.dump
WARNING: env00 returned 129 and left running for debug needs
Test: zdtm/live/static/env00, Result: FAIL


> Signed-off-by: Andrey Vagin <avagin at openvz.org>
> ---
>  test/zdtm.sh | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/test/zdtm.sh b/test/zdtm.sh
> index b5133c3..1eba6d7 100755
> --- a/test/zdtm.sh
> +++ b/test/zdtm.sh
> @@ -1,5 +1,8 @@
>  #!/bin/bash
>  
> +test -d /sys/fs/cgroup/perf_event/zdtm || mkdir /sys/fs/cgroup/perf_event/zdtm || exit 1
> +echo $$ > /sys/fs/cgroup/perf_event/zdtm/tasks
> +
>  ARCH=`uname -m | sed			\
>  		-e s/i.86/i386/		\
>  		-e s/sun4u/sparc64/	\
> @@ -582,8 +585,14 @@ EOF
>  
>  		save_fds $PID  $ddump/dump.fd
>  		save_maps $PID  $ddump/dump.maps
> -		setsid $CRIU_CPT $dump_cmd -D $ddump -o dump.log -v4 -t $PID $gen_args $cpt_args
> +		echo $$ > /sys/fs/cgroup/perf_event/tasks
> +		perf record -o $ddump/perf.dump -e raw_syscalls:sys_exit,raw_syscalls:sys_enter --cgroup test,test -a bash <<EOF
> +echo 0 > /sys/fs/cgroup/perf_event/zdtm/tasks &&
> +$CRIU_CPT $dump_cmd -D $ddump -o dump.log -v4 -t $PID $gen_args $cpt_args
> +EOF
>  		retcode=$?
> +		echo Use the following command to analize perf data:
> +		echo perf trace report -i $ddump/perf.dump
>  
>  		#
>  		# Here we may have two cases: either checkpoint is failed
>