From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756191Ab0JZGon (ORCPT ); Tue, 26 Oct 2010 02:44:43 -0400 Received: from hera.kernel.org ([140.211.167.34]:55637 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752060Ab0JZGom (ORCPT ); Tue, 26 Oct 2010 02:44:42 -0400 Date: Tue, 26 Oct 2010 06:44:05 GMT From: tip-bot for Masami Hiramatsu Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, namhyung@gmail.com, davem@davemloft.net, anil.s.keshavamurthy@intel.com, ananth@in.ibm.com, masami.hiramatsu.pt@hitachi.com, jbaron@redhat.com, tglx@linutronix.de, mhiramat@redhat.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, namhyung@gmail.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, ananth@in.ibm.com, masami.hiramatsu.pt@hitachi.com, tglx@linutronix.de, jbaron@redhat.com, mhiramat@redhat.com, mingo@elte.hu In-Reply-To: <20101025131801.19160.70939.stgit@ltc236.sdl.hitachi.co.jp> References: <20101025131801.19160.70939.stgit@ltc236.sdl.hitachi.co.jp> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] kprobes: Remove redundant text_mutex lock in optimize Message-ID: Git-Commit-ID: 43948f50276eca010a22726860dfe9a4e8130136 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 26 Oct 2010 06:44:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 43948f50276eca010a22726860dfe9a4e8130136 Gitweb: http://git.kernel.org/tip/43948f50276eca010a22726860dfe9a4e8130136 Author: Masami Hiramatsu AuthorDate: Mon, 25 Oct 2010 22:18:01 +0900 Committer: Ingo Molnar CommitDate: Mon, 25 Oct 2010 15:51:55 +0200 kprobes: Remove redundant text_mutex lock in optimize 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. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: David S. Miller Cc: Namhyung Kim Cc: Jason Baron Cc: Peter Zijlstra LKML-Reference: <20101025131801.19160.70939.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Ingo Molnar --- kernel/kprobes.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ec4210c..7c44133 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -74,7 +74,8 @@ 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; @@ -595,6 +596,7 @@ 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; @@ -607,17 +609,16 @@ 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;