From: Oleg Nesterov <oleg@redhat.com>
To: Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com>,
Jiri Olsa <jolsa@redhat.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 5/4] tracing: Simplify the ftrace_event_field iteration in f_next/f_show
Date: Wed, 17 Jul 2013 21:37:10 +0200 [thread overview]
Message-ID: <20130717193710.GC15312@redhat.com> (raw)
In-Reply-To: <20130717193017.GA15312@redhat.com>
On 07/17, Oleg Nesterov wrote:
>
> f_next() looks overcomplicated, and it is not strictly correct
> even if this doesn't matter.
Honestly, I do not know what the changelog can say to explain
this patch except "make the code simpler/cleaner".
To simplify the review, please see f_next/f_start with this patch
applied below. f_show() does field = list_entry(v, ...).
Probably makes sense anyway, I even tried to test it. So I would
not mind if you apply it as a separate cleanup ;)
Oleg.
static void *f_next(struct seq_file *m, void *v, loff_t *pos)
{
struct ftrace_event_call *call = m->private;
struct list_head *common_head = &ftrace_common_fields;
struct list_head *head = trace_get_fields(call);
struct list_head *node = v;
(*pos)++;
switch ((unsigned long)v) {
case FORMAT_HEADER:
node = common_head;
break;
case FORMAT_FIELD_SEPERATOR:
node = head;
break;
case FORMAT_PRINTFMT:
/* all done */
return NULL;
}
node = node->prev;
if (node == common_head)
return (void *)FORMAT_FIELD_SEPERATOR;
else if (node == head)
return (void *)FORMAT_PRINTFMT;
else
return node;
}
static void *f_start(struct seq_file *m, loff_t *pos)
{
void *p = (void *)FORMAT_HEADER;
loff_t l = 0;
while (p && l < *pos)
p = f_next(m, p, &l);
return p;
}
next prev parent reply other threads:[~2013-07-17 19:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-16 18:56 [RFC PATCH 0/4] tracing: fix open/delete fixes Oleg Nesterov
2013-07-16 18:57 ` [RFC PATCH 1/4] tracing: Change remove_event_from_tracers() to clear d_subdirs->i_private Oleg Nesterov
2013-07-16 18:57 ` [RFC PATCH 2/4] tracing: Turn "id"->i_private into call->event.type Oleg Nesterov
2013-07-16 19:49 ` Steven Rostedt
2013-07-17 19:39 ` Oleg Nesterov
2013-07-16 18:57 ` [RFC PATCH 3/4] tracing: Kill tracing_open/release_generic_file Oleg Nesterov
2013-07-16 19:51 ` Steven Rostedt
2013-07-17 19:19 ` Oleg Nesterov
2013-07-18 10:56 ` Masami Hiramatsu
2013-07-18 14:55 ` Oleg Nesterov
2013-07-16 18:57 ` [RFC PATCH 4/4] tracing: Change ftrace_event_filter_fops to rely on event_mutex/i_private Oleg Nesterov
2013-07-17 2:36 ` [RFC PATCH 0/4] tracing: fix open/delete fixes Masami Hiramatsu
2013-07-17 14:43 ` Oleg Nesterov
2013-07-18 8:18 ` Masami Hiramatsu
2013-07-18 15:27 ` Oleg Nesterov
2013-07-17 19:30 ` [RFC PATCH 5/4] tracing: Simplify the ftrace_event_field iteration in f_next/f_show Oleg Nesterov
2013-07-17 19:37 ` Oleg Nesterov [this message]
2013-07-17 19:30 ` [RFC PATCH 6/4] tracing: Change f_start() to verify i_private under event_mutex Oleg Nesterov
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