From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id 1C9FD6B0003 for ; Mon, 9 Apr 2018 04:29:34 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id t133so3720634wmt.6 for ; Mon, 09 Apr 2018 01:29:34 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id o56si63703edc.525.2018.04.09.01.29.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 09 Apr 2018 01:29:32 -0700 (PDT) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w398JCxf100057 for ; Mon, 9 Apr 2018 04:29:31 -0400 Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111]) by mx0b-001b2d01.pphosted.com with ESMTP id 2h80dd9sgk-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Mon, 09 Apr 2018 04:29:30 -0400 Received: from localhost by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 9 Apr 2018 09:29:28 +0100 Subject: Re: [PATCH v2 9/9] perf probe: Support SDT markers having reference counter (semaphore) References: <20180404083110.18647-1-ravi.bangoria@linux.vnet.ibm.com> <20180404083110.18647-10-ravi.bangoria@linux.vnet.ibm.com> <20180409162856.df4c32b840eb5f2ef8c028f1@kernel.org> From: Ravi Bangoria Date: Mon, 9 Apr 2018 13:59:16 +0530 MIME-Version: 1.0 In-Reply-To: <20180409162856.df4c32b840eb5f2ef8c028f1@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US Message-Id: <643a8fb2-fb96-8dbe-9f36-2540bd8a1de5@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Masami Hiramatsu Cc: oleg@redhat.com, peterz@infradead.org, srikar@linux.vnet.ibm.com, rostedt@goodmis.org, acme@kernel.org, ananth@linux.vnet.ibm.com, akpm@linux-foundation.org, alexander.shishkin@linux.intel.com, alexis.berlemont@gmail.com, corbet@lwn.net, dan.j.williams@intel.com, jolsa@redhat.com, kan.liang@intel.com, kjlx@templeofstupid.com, kstewart@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, milian.wolff@kdab.com, mingo@redhat.com, namhyung@kernel.org, naveen.n.rao@linux.vnet.ibm.com, pc@us.ibm.com, tglx@linutronix.de, yao.jin@linux.intel.com, fengguang.wu@intel.com, jglisse@redhat.com, Ravi Bangoria Hi Masami, On 04/09/2018 12:58 PM, Masami Hiramatsu wrote: > Hi Ravi, > > On Wed, 4 Apr 2018 14:01:10 +0530 > Ravi Bangoria wrote: > >> @@ -2054,15 +2060,21 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev) >> } >> >> /* Use the tp->address for uprobes */ >> - if (tev->uprobes) >> + if (tev->uprobes) { >> err = strbuf_addf(&buf, "%s:0x%lx", tp->module, tp->address); >> - else if (!strncmp(tp->symbol, "0x", 2)) >> + if (uprobe_ref_ctr_is_supported() && >> + tp->ref_ctr_offset && >> + err >= 0) >> + err = strbuf_addf(&buf, "(0x%lx)", tp->ref_ctr_offset); > If the kernel doesn't support uprobe_ref_ctr but the event requires > to increment uprobe_ref_ctr, I think we should (at least) warn user here. pr_debug("A semaphore is associated with %s:%s and seems your kernel doesn't support it.\n" A A A A A A A A tev->group, tev->event); Looks good? >> @@ -776,14 +784,21 @@ static char *synthesize_sdt_probe_command(struct sdt_note *note, >> { >> struct strbuf buf; >> char *ret = NULL, **args; >> - int i, args_count; >> + int i, args_count, err; >> + unsigned long long ref_ctr_offset; >> >> if (strbuf_init(&buf, 32) < 0) >> return NULL; >> >> - if (strbuf_addf(&buf, "p:%s/%s %s:0x%llx", >> - sdtgrp, note->name, pathname, >> - sdt_note__get_addr(note)) < 0) >> + err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx", >> + sdtgrp, note->name, pathname, >> + sdt_note__get_addr(note)); >> + >> + ref_ctr_offset = sdt_note__get_ref_ctr_offset(note); >> + if (uprobe_ref_ctr_is_supported() && ref_ctr_offset && err >= 0) >> + err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset); > We don't have to care about uprobe_ref_ctr support here, because > this information will be just cached, not directly written to > uprobe_events. Sure, will remove the check. Thanks for the review :). Ravi