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Commit 43948f50 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
Browse files

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: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101025131801.19160.70939.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2c78ffec

kernel/kprobes.c

+4 −3
Original line number Diff line number Diff line
@@ -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;