From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932478Ab3GVLTJ (ORCPT ); Mon, 22 Jul 2013 07:19:09 -0400 Received: from mail7.hitachi.co.jp ([133.145.228.42]:49443 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932238Ab3GVLTH (ORCPT ); Mon, 22 Jul 2013 07:19:07 -0400 Message-ID: <51ED1528.8070807@hitachi.com> Date: Mon, 22 Jul 2013 20:19:04 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Tom Zanussi Cc: rostedt@goodmis.org, jovi.zhangwei@huawei.com, linux-kernel@vger.kernel.org, Oleg Nesterov Subject: Re: [PATCH v3 2/9] tracing: add basic event trigger framework References: <8392a194f5994bc59b387bcde5cab5588e341fff.1374245042.git.tom.zanussi@linux.intel.com> In-Reply-To: <8392a194f5994bc59b387bcde5cab5588e341fff.1374245042.git.tom.zanussi@linux.intel.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2013/07/20 0:09), Tom Zanussi wrote: > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h > index af6eb2c..d3e8626 100644 > --- a/kernel/trace/trace.h > +++ b/kernel/trace/trace.h > @@ -1021,6 +1021,43 @@ extern int event_trace_del_tracer(struct trace_array *tr); > extern struct mutex event_mutex; > extern struct list_head ftrace_events; > > +extern const struct file_operations event_trigger_fops; > + > +extern int register_trigger_cmds(void); > + > +struct event_trigger_ops { > + void (*func)(void **data); > + int (*init)(struct event_trigger_ops *ops, > + void **data); > + void (*free)(struct event_trigger_ops *ops, > + void **data); > + int (*print)(struct seq_file *m, > + struct event_trigger_ops *ops, > + void *data); > +}; Please add comments what each ops does. :) > + > +struct event_command { > + struct list_head list; > + char *name; > + enum trigger_mode trigger_mode; > + int (*func)(struct event_command *cmd_ops, > + void *cmd_data, char *glob, char *cmd, > + char *params, int enable); > + int (*reg)(char *glob, > + struct event_trigger_ops *trigger_ops, > + void *trigger_data, void *cmd_data); > + void (*unreg)(char *glob, > + struct event_trigger_ops *trigger_ops, > + void *trigger_data, void *cmd_data); > + int (*set_filter)(char *filter_str, > + void *trigger_data, > + void *cmd_data); > + struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param); > +}; Ditto. [...] > +static int event_trigger_regex_open(struct inode *inode, struct file *file) > +{ > + struct trigger_iterator *iter; > + int ret = 0; > + > + iter = kzalloc(sizeof(*iter), GFP_KERNEL); > + if (!iter) > + return -ENOMEM; > + > + iter->file = inode->i_private; > + > + mutex_lock(&event_mutex); > + > + if (file->f_mode & FMODE_READ) { > + ret = seq_open(file, &event_triggers_seq_ops); > + if (!ret) { > + struct seq_file *m = file->private_data; > + m->private = iter; > + } else { > + /* Failed */ > + kfree(iter); > + } > + } else > + file->private_data = iter; > + Perhaps, unfortunately, this will not work correctly if currently discussing bugfix approach is applied. Oleg, would you help us what this should be? > + mutex_unlock(&event_mutex); > + > + return ret; > +} [...] > +static int unregister_event_command(struct event_command *cmd, > + struct list_head *cmd_list, > + struct mutex *cmd_list_mutex) > +{ > + struct event_command *p, *n; > + int ret = -ENODEV; > + > + mutex_lock(cmd_list_mutex); > + list_for_each_entry_safe(p, n, cmd_list, list) { > + if (strcmp(cmd->name, p->name) == 0) { > + ret = 0; > + list_del_init(&p->list); > + goto out_unlock; > + } > + } > + out_unlock: > + mutex_unlock(cmd_list_mutex); > + > + return ret; > +} OK, it seems that this is used only for rollback process in __init functions. If so, it should have __init (and a comment), or we need a refcount to check no one uses the command anymore. Thank you, -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com