Re: [PATCH 2/2] perf tools: Increase MAX_EVENT_LENGTH

[Peter Zijlstra <peterz@infradead.org>]

On Thu, 2009-09-17 at 11:02 +0200, Frederic Weisbecker wrote:
> On Thu, Sep 17, 2009 at 04:34:51PM +0800, Li Zefan wrote:
> > The name length of some trace events is longer than 30, like
> > sys_enter_sched_get_priority_max and ext4_mb_discard_preallocations.
> > 
> > Passing those events to perf-record will fail, try:
> > 
> >   # ./perf record -f -e syscalls:sys_enter_sched_get_priority_max -F 1 -a
> > 
> > Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> > ---
> >  tools/perf/util/parse-events.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index 034245e..c9ef944 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -145,7 +145,7 @@ static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
> >  	   (strcmp(evt_dirent.d_name, "..")) &&				       \
> >  	   (!tp_event_has_id(&sys_dirent, &evt_dirent)))
> >  
> > -#define MAX_EVENT_LENGTH 30
> > +#define MAX_EVENT_LENGTH 40

This is userspace, is there any reason to be cheap with memory like
this?

Why not stick in 1024 and be done for a while?