From: Masami Hiramatsu <mhiramat@redhat.com>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Takashi Nishiie <t-nishiie@np.css.fujitsu.com>,
"'Alexey Dobriyan'" <adobriyan@gmail.com>,
"'Peter Zijlstra'" <peterz@infradead.org>,
"'Steven Rostedt'" <rostedt@goodmis.org>,
"'Frank Ch. Eigler'" <fche@redhat.com>,
"'Ingo Molnar'" <mingo@elte.hu>,
"'LKML'" <linux-kernel@vger.kernel.org>,
"'systemtap-ml'" <systemtap@sources.redhat.com>,
"'Hideo AOKI'" <haoki@redhat.com>
Subject: Re: [RFC PATCH] Kernel Tracepoints (update)
Date: Thu, 03 Jul 2008 15:29:00 -0000 [thread overview]
Message-ID: <486CEFDB.7070508@redhat.com> (raw)
In-Reply-To: <20080627133622.GA15210@Krystal>
Hi Mathieu,
I found a bug.
Mathieu Desnoyers wrote:
[...]
> +/*
> + * Remove the tracepoint from the tracepoint hash table. Must be called with
> + * mutex_lock held.
> + */
> +static int remove_tracepoint(const char *name)
> +{
> + struct hlist_head *head;
> + struct hlist_node *node;
> + struct tracepoint_entry *e;
> + int found = 0;
> + size_t len = strlen(name) + 1;
> + u32 hash = jhash(name, len-1, 0);
> +
> + head = &tracepoint_table[hash & ((1 << TRACEPOINT_HASH_BITS)-1)];
> + hlist_for_each_entry(e, node, head, hlist) {
> + if (!strcmp(name, e->name)) {
> + found = 1;
> + break;
> + }
> + }
> + if (!found)
> + return -ENOENT;
before removing, you have to ensure refcount == 0. So,
if (e->refcount != 0)
return -EBUSY;
> + hlist_del(&e->hlist);
> + /* Make sure the call_rcu has been executed */
> + if (e->rcu_pending)
> + rcu_barrier();
> + kfree(e);
> + return 0;
> +}
Thank you,
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com
next prev parent reply other threads:[~2008-07-03 15:29 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-20 19:36 [RFC][Patch 2/2] markers: example of irq regular kernel markers Masami Hiramatsu
2008-06-20 22:16 ` Mathieu Desnoyers
2008-06-20 23:23 ` Masami Hiramatsu
2008-06-21 15:08 ` KOSAKI Motohiro
2008-06-21 18:04 ` Steven Rostedt
2008-06-21 19:41 ` Frank Ch. Eigler
2008-06-22 4:03 ` Steven Rostedt
2008-06-22 4:32 ` Peter Zijlstra
2008-06-22 17:12 ` Frank Ch. Eigler
2008-06-23 2:20 ` Masami Hiramatsu
2008-06-23 7:08 ` KOSAKI Motohiro
2008-06-22 18:03 ` Frank Ch. Eigler
2008-06-22 18:27 ` Masami Hiramatsu
2008-06-21 10:14 ` Peter Zijlstra
2008-06-23 3:06 ` [RFC] Tracepoint proposal Mathieu Desnoyers
2008-06-23 6:34 ` Alexey Dobriyan
2008-06-23 6:51 ` Mathieu Desnoyers
2008-06-24 7:15 ` Alexey Dobriyan
2008-06-24 11:39 ` Masami Hiramatsu
2008-06-24 13:23 ` Takashi Nishiie
2008-06-24 16:23 ` Frank Ch. Eigler
2008-06-24 19:43 ` Masami Hiramatsu
2008-06-25 1:08 ` KOSAKI Motohiro
2008-06-25 1:36 ` Masami Hiramatsu
2008-06-25 1:49 ` Mathieu Desnoyers
2008-06-26 16:20 ` [RFC PATCH] Tracepoint sched probes Mathieu Desnoyers
2008-06-26 17:01 ` [RFC PATCH] Kernel Tracepoints Mathieu Desnoyers
2008-06-27 13:21 ` Masami Hiramatsu
2008-06-27 15:00 ` Mathieu Desnoyers
2008-06-29 18:46 ` Masami Hiramatsu
2008-06-30 18:21 ` Mathieu Desnoyers
2008-06-27 15:07 ` Mathieu Desnoyers
2008-06-30 20:11 ` Masami Hiramatsu
2008-06-27 15:48 ` Mathieu Desnoyers
2008-06-28 0:05 ` Masami Hiramatsu
2008-06-30 17:14 ` Mathieu Desnoyers
2008-06-30 20:17 ` Masami Hiramatsu
2008-07-03 15:13 ` Mathieu Desnoyers
2008-07-03 18:53 ` Masami Hiramatsu
2008-06-27 16:11 ` [RFC PATCH] Kernel Tracepoints (update) Mathieu Desnoyers
2008-07-03 15:29 ` Masami Hiramatsu [this message]
2008-07-03 15:47 ` Mathieu Desnoyers
2008-07-03 18:19 ` Mathieu Desnoyers
2008-07-03 18:48 ` Masami Hiramatsu
2008-06-24 11:06 ` [RFC] Tracepoint proposal Masami Hiramatsu
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