perf trace: Only insert blank duration bracket when tracing syscalls

When printing just events, i.e. '--no-sys --ev some:events' it makes no
sense to waste screen space.

Before:

 # trace --no-sys --ev probe:*
 84481.704 (         ): probe:vfs_getname:(ffffffff811ed023) pathname="/etc/services")
 84481.892 (         ): probe:vfs_getname:(ffffffff811ed023) pathname="/etc/services")
 84482.230 (         ): probe:vfs_getname:(ffffffff811ed023) pathname="/etc/resolv.conf")
 84482.481 (         ): probe:vfs_getname:(ffffffff811ed023) pathname="/etc/hosts")
 85097.725 (         ): probe:vfs_getname:(ffffffff811ed023) pathname="/root"
 #

After:

 # trace --no-sys --ev probe:*
 0.000 probe:vfs_getname:(ffffffff811ed023) pathname="/root")
 1.711 probe:vfs_getname:(ffffffff811ed023) pathname="/etc/localtime")
 2.103 probe:vfs_getname:(ffffffff811ed023) pathname="/etc/localtime")
^C#

Cc: Adrian Hunter <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Don Zickus <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions