From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5128EC4332B for ; Mon, 23 Mar 2020 13:04:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3030A2072E for ; Mon, 23 Mar 2020 13:04:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728294AbgCWNED (ORCPT ); Mon, 23 Mar 2020 09:04:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:34838 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728287AbgCWNED (ORCPT ); Mon, 23 Mar 2020 09:04:03 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 13B8D20658; Mon, 23 Mar 2020 13:04:02 +0000 (UTC) Date: Mon, 23 Mar 2020 09:04:01 -0400 From: Steven Rostedt To: Masami Hiramatsu Cc: Taeung Song , linux-trace-users@vger.kernel.org, "David S. Miller" Subject: Re: How to recheck 'maxactive' ? Message-ID: <20200323090401.5ef12790@gandalf.local.home> In-Reply-To: <20200323154741.0643126b3684c950bb37bf7e@kernel.org> References: <4762764a-6df7-bc93-ed60-e336146dce1f@gmail.com> <20200323154741.0643126b3684c950bb37bf7e@kernel.org> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-trace-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-users@vger.kernel.org On Mon, 23 Mar 2020 15:47:41 +0900 Masami Hiramatsu wrote: > Hi Taeung, > > On Sun, 22 Mar 2020 23:06:20 +0900 > Taeung Song wrote: > > > Hi, > > > > After setting 'maxactive' for kretprobe, > > how can I recheck the value of 'maxactive' ? > > For example, in order to distinguish the difference > > between two kretprobe events > > (kmem_cache_alloc_node and kmem_cache_alloc_node10) > > > > $ cd /sys/kernel/debug/tracing > > $ echo 'r:kmem_cache_alloc_node kmem_cache_alloc_node' >> kprobe_events > > $ echo 'r10:kmem_cache_alloc_node10 kmem_cache_alloc_node' >> > > kprobe_events > > > > $ cat kprobe_events > > r:kprobes/kmem_cache_alloc_node kmem_cache_alloc_node > > r:kprobes/kmem_cache_alloc_node10 kmem_cache_alloc_node > > Oops! good catch. That must be a bug, since the kprobe_events design policy > is to support following operation. > > $ cat kprobe_events > /etc/event_setting > (reboot) > $ cat /etc/event_setting > kprobe_events > > What about below patch? > > >From 935ed56819f2bfb7ac977f5c63273c9a6e3dfb42 Mon Sep 17 00:00:00 2001 > From: Masami Hiramatsu > Date: Mon, 23 Mar 2020 10:57:48 +0900 > Subject: [PATCH] ftrace/kprobe: Show the maxactive number on kprobe_events > > Show maxactive parameter on kprobe_events. > This allows user to save the current configuration and > restore it without losing maxactive parameter. > Hi Masami, Can you resend this patch as a stand alone (so that it shows up as a patch on the mailing lists). Thanks! -- Steve > Signed-off-by: Masami Hiramatsu > --- > kernel/trace/trace_kprobe.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 362cca52f5de..d0568af4a0ef 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -1078,6 +1078,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) > int i; > > seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); > + if (trace_kprobe_is_return(tk) && tk->rp.maxactive) > + seq_printf(m, "%d", tk->rp.maxactive); > seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), > trace_probe_name(&tk->tp)); >