From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 57ED37DF93 for ; Wed, 4 Jul 2018 04:53:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753617AbeGDExd (ORCPT ); Wed, 4 Jul 2018 00:53:33 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40480 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751831AbeGDExc (ORCPT ); Wed, 4 Jul 2018 00:53:32 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w644mjxD080700 for ; Wed, 4 Jul 2018 00:53:32 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2k0k43s1kt-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 04 Jul 2018 00:53:32 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 4 Jul 2018 05:53:30 +0100 Received: from b06cxnps3074.portsmouth.uk.ibm.com (9.149.109.194) by e06smtp02.uk.ibm.com (192.168.101.132) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 4 Jul 2018 05:53:24 +0100 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w644rNR533292540 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 4 Jul 2018 04:53:23 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D413EAE04D; Wed, 4 Jul 2018 07:53:25 +0100 (BST) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9457AAE051; Wed, 4 Jul 2018 07:53:22 +0100 (BST) Received: from [9.124.31.203] (unknown [9.124.31.203]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 4 Jul 2018 07:53:22 +0100 (BST) Subject: Re: [PATCH v5 06/10] Uprobes: Support SDT markers having reference count (semaphore) To: Oleg Nesterov Cc: srikar@linux.vnet.ibm.com, rostedt@goodmis.org, mhiramat@kernel.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, corbet@lwn.net, linux-doc@vger.kernel.org, ananth@linux.vnet.ibm.com, alexis.berlemont@gmail.com, naveen.n.rao@linux.vnet.ibm.com, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux@armlinux.org.uk, ralf@linux-mips.org, paul.burton@mips.com, Ravi Bangoria References: <20180628052209.13056-1-ravi.bangoria@linux.ibm.com> <20180628052209.13056-7-ravi.bangoria@linux.ibm.com> <20180701210935.GA14404@redhat.com> <0c543791-f3b7-5a4b-f002-e1c76bb430c0@linux.ibm.com> <20180702180156.GA31400@redhat.com> <20180703163645.GA23144@redhat.com> <20180703172543.GC23144@redhat.com> From: Ravi Bangoria Date: Wed, 4 Jul 2018 10:23:19 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180703172543.GC23144@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18070404-0008-0000-0000-0000024F6F7C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18070404-0009-0000-0000-000021B5813F Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-04_01:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=892 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807040056 Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi Oleg, On 07/03/2018 10:55 PM, Oleg Nesterov wrote: > On 07/03, Oleg Nesterov wrote: >> >> In short. There is a 1:1 relationship between uprobe_write_opcode(is_register => 1) >> and install_breakpoint(), and between uprobe_write_opcode(is_register => 0) and >> remove_breakpoint(). Whatever uprobe_write_opcode() can do if is_register == 1 can be >> done in install_breakpoint(), the same for is_register == 0 and remove_breakpont(). >> >> What have I missed? > > Ah. I missed the fact that uprobe_write_opcode() doesn't do update_ref_ctr() if > verify_opcode() returns false. > > Now I understand what did you mean by "for each consumer". So if we move this logic > into install/remove_breakpoint as I tried to suggest, we will also need another error > code for the case when verify_opcode() returns false. Ok so if we can use verify_opcode() inside install_breakpoint(), we can probably move implementation logic in install/remove_breakpoint(). Let me explore that more. Thanks, Ravi -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html