From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13639 invoked by alias); 18 May 2010 20:07:42 -0000 Received: (qmail 13632 invoked by uid 22791); 18 May 2010 20:07:41 -0000 X-SWARE-Spam-Status: No, hits=-5.7 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 18 May 2010 20:07:36 +0000 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o4IK7YEp020480 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 18 May 2010 16:07:34 -0400 Received: from localhost6.localdomain6 (dhcp-100-3-156.bos.redhat.com [10.16.3.156]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o4IK7WuC009482; Tue, 18 May 2010 16:07:32 -0400 From: Masami Hiramatsu Subject: [PATCH -tip v2 2/5] [CLEANUP] kprobes: Remove redundant text_mutex lock in optimize To: Ingo Molnar , lkml Cc: systemtap, DLE, Masami Hiramatsu , Ananth N Mavinakayanahalli , Ingo Molnar , Jim Keniston , Jason Baron , Mathieu Desnoyers Date: Wed, 19 May 2010 05:03:00 -0000 Message-ID: <20100518201259.6058.23226.stgit@localhost6.localdomain6> In-Reply-To: <20100518201244.6058.73083.stgit@localhost6.localdomain6> References: <20100518201244.6058.73083.stgit@localhost6.localdomain6> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2010-q2/txt/msg00379.txt.bz2 Remove text_mutex locking in optimize_all_kprobes, because this function doesn't modify text. It simply queues probes on optimization list for kprobe_optimizer worker thread. Changes in v2: - Update changelog. - Add comments for (un)optimize_all_kprobes. - Update kprobe_mutex comment. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Ingo Molnar Cc: Jim Keniston Cc: Jason Baron Cc: Mathieu Desnoyers --- kernel/kprobes.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 282035f..f1351f2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -73,7 +73,8 @@ static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; /* NOTE: change this value only with kprobe_mutex held */ static bool kprobes_all_disarmed; -static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ +/* This protects kprobe_table and optimizing_list */ +static DEFINE_MUTEX(kprobe_mutex); static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; static struct { spinlock_t lock ____cacheline_aligned_in_smp; @@ -594,6 +595,7 @@ static __kprobes void try_to_optimize_kprobe(struct kprobe *p) } #ifdef CONFIG_SYSCTL +/* This should be called with kprobe_mutex locked */ static void __kprobes optimize_all_kprobes(void) { struct hlist_head *head; @@ -606,17 +608,16 @@ static void __kprobes optimize_all_kprobes(void) return; kprobes_allow_optimization = true; - mutex_lock(&text_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) if (!kprobe_disabled(p)) optimize_kprobe(p); } - mutex_unlock(&text_mutex); printk(KERN_INFO "Kprobes globally optimized\n"); } +/* This should be called with kprobe_mutex locked */ static void __kprobes unoptimize_all_kprobes(void) { struct hlist_head *head; -- Masami Hiramatsu e-mail: mhiramat@redhat.com