From: Arnaldo Carvalho de Melo <acme@infradead.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Masami Hiramatsu <mhiramat@redhat.com>,
Mark Wielaard <mjw@redhat.com>,
Ingo Molnar <mingo@elte.hu>,
lkml <linux-kernel@vger.kernel.org>,
systemtap <systemtap@sources.redhat.com>,
DLE <dle-develop@lists.sourceforge.net>,
Paul Mackerras <paulus@samba.org>,
Mike Galbraith <efault@gmx.de>
Subject: Re: [PATCH -tip 10/10] perf probe: Accessing members in data structures
Date: Tue, 23 Mar 2010 16:27:00 -0000 [thread overview]
Message-ID: <20100323162719.GG4066@ghostprotocols.net> (raw)
In-Reply-To: <1269359713.5109.95.camel@twins>
Em Tue, Mar 23, 2010 at 04:55:13PM +0100, Peter Zijlstra escreveu:
> On Thu, 2010-03-18 at 04:28 +0100, Frederic Weisbecker wrote:
> > On Wed, Mar 17, 2010 at 03:14:43PM -0400, Masami Hiramatsu wrote:
> > > Mark Wielaard wrote:
> > > > If you find that a problem then you can do like SystemTap does and allow
> > > > '.' in place of '->'. In the code you already use the
> > > > perf_probe_arg_field ref flag only to check that the DIE gives you the
> > > > same information. So you could just drop that and use any separator.
> > > > Then you decide based on whether you see a DW_TAG_pointer_type. This
> > > > gives the user some extra flexibility by letting them not having to care
> > > > about specifying extra type information already available elsewhere.
> > > Thanks, when designing this feature, I considered it too.
> > > Since perf probe already support displaying source code by --line option,
> > > users will read the probed code itself and try to probe it. In that case,
> > > I think they naturally use '.' and '->' as they read (they might try to
> > > copy & paste it).
> > > So, I think that it would be good to support both of '.' and '->' as
> > > they are used in the code, because it will not confuse users.
> > And lets people use what is common for them: expressions that follow
> > C rules in the context.
> > And those who will be more familiar with perf probe will know they can
> > use the simplified "." based scheme.
> I'd expect a syntax error when I mix up '.' and '->'.
Yup, I'd stick with following the C language rules.
- Arnaldo
next prev parent reply other threads:[~2010-03-23 16:27 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-16 21:56 [PATCH -tip 00/10] perf-probe updates - data-structure support, etc Masami Hiramatsu
2010-03-16 21:57 ` [PATCH -tip 05/10] perf probe: Rename some die_get_* functions Masami Hiramatsu
2010-03-17 11:29 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2010-03-16 21:57 ` [PATCH -tip 04/10] perf probe: Rename session to param Masami Hiramatsu
2010-03-17 11:29 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2010-03-16 21:57 ` [PATCH -tip 03/10] perf probe: Move add-probe routine under util/ Masami Hiramatsu
2010-03-17 11:29 ` [tip:perf/core] perf probe: Move add-probe routine to util/ tip-bot for Masami Hiramatsu
2010-03-16 21:57 ` [PATCH -tip 06/10] perf probe: Introduce die_find_child() function Masami Hiramatsu
2010-03-17 11:29 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2010-03-16 21:57 ` [PATCH -tip 07/10] perf probe: Add --dry-run option Masami Hiramatsu
2010-03-17 11:30 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2010-03-16 21:57 ` [PATCH -tip 01/10] perf tools: Introduce xzalloc() for detecting out of memory Masami Hiramatsu
2010-03-17 11:28 ` [tip:perf/core] perf tools: Introduce xzalloc() for detecting out of memory conditions tip-bot for Masami Hiramatsu
2010-03-16 21:57 ` [PATCH -tip 02/10] perf probe: Use wrapper functions Masami Hiramatsu
2010-03-17 11:29 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2010-03-16 21:58 ` [PATCH -tip 10/10] perf probe: Accessing members in data structures Masami Hiramatsu
2010-03-17 10:25 ` Mark Wielaard
2010-03-17 19:14 ` Masami Hiramatsu
2010-03-18 3:28 ` Frederic Weisbecker
2010-03-20 4:20 ` Masami Hiramatsu
2010-03-23 15:55 ` Peter Zijlstra
2010-03-23 16:27 ` Arnaldo Carvalho de Melo [this message]
2010-03-17 11:31 ` [tip:perf/core] perf probe: Add data structure member access support tip-bot for Masami Hiramatsu
2010-03-16 21:58 ` [PATCH -tip 09/10] perf probe: List probes with line number and file name Masami Hiramatsu
2010-03-17 11:31 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2010-03-16 21:58 ` [PATCH -tip 08/10] perf probe: Introduce kprobe_trace_event and perf_probe_event Masami Hiramatsu
2010-03-17 11:31 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2010-03-17 10:35 ` [PATCH -tip 00/10] perf-probe updates - data-structure support, etc Ingo Molnar
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