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From: Masami Hiramatsu on 18 May 2010 16:10 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 <mhiramat(a)redhat.com> Cc: Ananth N Mavinakayanahalli <ananth(a)in.ibm.com> Cc: Ingo Molnar <mingo(a)elte.hu> Cc: Jim Keniston <jkenisto(a)us.ibm.com> Cc: Jason Baron <jbaron(a)redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> --- 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(a)redhat.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |