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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 A301EC433ED for ; Thu, 13 May 2021 12:26:45 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0CB69611CA for ; Thu, 13 May 2021 12:26:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0CB69611CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id C7A10100EAB62; Thu, 13 May 2021 05:26:44 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=kjain@linux.ibm.com; receiver= Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 885C8100EBB9C for ; Thu, 13 May 2021 05:26:42 -0700 (PDT) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 14DCNBxV119669; Thu, 13 May 2021 08:26:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=U/4Dpg6rGeqjovo2MNoB7wa0IvLzTG7wFV72MKbtHnY=; b=PerPeYqc/oSWFWodyRXsCBsU22HDaaCjzzEgxW+LuVbfxsL9bOIzFQ4vHbJCKU4Iuxd9 z4XLk1I3YO9h2EOExeRkNRCP+CIXX7Ml18nfH0N8KfSxnUGgOun6kpDvIONSbpvEF7Ih KiDRQCI5s7+G4roNhFAGnYfEMunpoZFs9PIMGIzEGeqLLjrxYX6dAhd8dnKHN90gYeBH dNC1kupnEUPd5YKCNQEiZIFQWC9DNrjpaWG4EPl5A9XTI/Z3SLHvoQzvw+GKXtvVWdYx oRTjOS5GRfgusS1tiJQtLczYOhYZWYYXyxgomTmLcTwl3vazMwj6GkMEO6BI5DltkyA5 Aw== Received: from ppma01dal.us.ibm.com (83.d6.3fa9.ip4.static.sl-reverse.com [169.63.214.131]) by mx0a-001b2d01.pphosted.com with ESMTP id 38h2m5ah2e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 13 May 2021 08:26:29 -0400 Received: from pps.filterd (ppma01dal.us.ibm.com [127.0.0.1]) by ppma01dal.us.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 14DCCppv026233; Thu, 13 May 2021 12:26:28 GMT Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by ppma01dal.us.ibm.com with ESMTP id 38dj9a5xav-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 13 May 2021 12:26:28 +0000 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 14DCQQum16777672 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 13 May 2021 12:26:26 GMT Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8CFC7BE04F; Thu, 13 May 2021 12:26:26 +0000 (GMT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0515EBE05A; Thu, 13 May 2021 12:26:16 +0000 (GMT) Received: from localhost.localdomain (unknown [9.199.44.200]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 13 May 2021 12:26:16 +0000 (GMT) Subject: Re: [RFC 1/4] drivers/nvdimm: Add perf interface to expose nvdimm performance stats To: Peter Zijlstra References: <20210512163824.255370-1-kjain@linux.ibm.com> <20210512163824.255370-2-kjain@linux.ibm.com> From: kajoljain Message-ID: <37015d53-050a-acef-2958-b1ff5d02800b@linux.ibm.com> Date: Thu, 13 May 2021 17:56:14 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: EvtomYgSIUC0jAMqMvwF4gaUntt7Qasr X-Proofpoint-GUID: EvtomYgSIUC0jAMqMvwF4gaUntt7Qasr X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-05-13_06:2021-05-12,2021-05-13 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 spamscore=0 impostorscore=0 phishscore=0 priorityscore=1501 clxscore=1011 suspectscore=0 malwarescore=0 bulkscore=0 mlxlogscore=999 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105130093 Message-ID-Hash: UNM7WV7I6O3F73Z2CT6CJH2XMPLGVQLW X-Message-ID-Hash: UNM7WV7I6O3F73Z2CT6CJH2XMPLGVQLW X-MailFrom: kjain@linux.ibm.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, maddy@linux.vnet.ibm.com, aneesh.kumar@linux.ibm.com, vaibhav@linux.ibm.com, atrajeev@linux.vnet.ibm.com, tglx@linutronix.de X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On 5/12/21 10:57 PM, Peter Zijlstra wrote: > On Wed, May 12, 2021 at 10:08:21PM +0530, Kajol Jain wrote: >> +static void nvdimm_pmu_read(struct perf_event *event) >> +{ >> + struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu); >> + >> + /* jump to arch/platform specific callbacks if any */ >> + if (nd_pmu && nd_pmu->read) >> + nd_pmu->read(event, nd_pmu->dev); >> +} >> + >> +static void nvdimm_pmu_del(struct perf_event *event, int flags) >> +{ >> + struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu); >> + >> + /* jump to arch/platform specific callbacks if any */ >> + if (nd_pmu && nd_pmu->del) >> + nd_pmu->del(event, flags, nd_pmu->dev); >> +} >> + >> +static int nvdimm_pmu_add(struct perf_event *event, int flags) >> +{ >> + struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu); >> + >> + if (flags & PERF_EF_START) >> + /* jump to arch/platform specific callbacks if any */ >> + if (nd_pmu && nd_pmu->add) >> + return nd_pmu->add(event, flags, nd_pmu->dev); >> + return 0; >> +} > > What's the value add here? Why can't you directly set driver pointers? I > also don't really believe ->{add,del,read} can be optional and still > have a sane driver. > Hi Peter, The intend for adding these callbacks is to give flexibility to the arch/platform specific driver code to use its own routine for getting counter data or specific checks/operations. Arch/platform driver code would have different method to get the counter data like IBM pseries nmem* device which uses a hypervisor call(hcall). But yes the current read/add/del functions are not adding value. We could add an arch/platform specific function which could handle the capturing of the counter data and do the rest of the operation here, is this approach better? Thanks, Kajol Jain _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org