Re: [PATCH] perf tool: Fix ppid for synthesized fork events

[David Ahern]

On 3/25/15 7:24 AM, Arnaldo Carvalho de Melo wrote:
> So it starts when there are tons of threads in the system, for which
> synthezing from /proc will have to take place, without looking again at
> that patch, I can't think about what would be a problem :-\

3 extra lines are read from /proc/pid/status:

Name:	bash
State:	S (sleeping)
Tgid:	6046

< current patch breaks here>

Ngid:	0
Pid:	6046
PPid:	6045

< my patch reads these 3 lines, repeats the memcmp and does an atoi on 
the PPid: value >

Let me remove that loop by reading in 4k at a time and making a single 
pass. That should bring down the overhead, but filling in the ppid will 
add some.

David

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/