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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 7BE19C3B1A1 for ; Fri, 14 Feb 2020 17:25:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5ECC5222C2 for ; Fri, 14 Feb 2020 17:25:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391317AbgBNRY7 (ORCPT ); Fri, 14 Feb 2020 12:24:59 -0500 Received: from mga17.intel.com ([192.55.52.151]:43172 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390928AbgBNRY7 (ORCPT ); Fri, 14 Feb 2020 12:24:59 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Feb 2020 09:24:56 -0800 X-IronPort-AV: E=Sophos;i="5.70,441,1574150400"; d="scan'208";a="223081205" Received: from ddalessa-mobl.amr.corp.intel.com (HELO [10.254.204.146]) ([10.254.204.146]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 14 Feb 2020 09:24:54 -0800 Subject: Re: [PATCH 1/3] infiniband: hw: hfi1: verbs.c: Use built-in RCU list checking To: Madhuparna Bhowmik , Jason Gunthorpe Cc: mike.marciniszyn@intel.com, "Paul E. McKenney" , Joel Fernandes , Amol Grover , linux-kernel-mentees@lists.linuxfoundation.org, rcu@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200114162345.19995-1-madhuparnabhowmik04@gmail.com> <20200114165740.GB22037@ziepe.ca> <74adec84-ec5b-ea1b-7adf-3f8608838259@intel.com> <25133367-6544-d0af-ae30-5178909748b1@intel.com> From: Dennis Dalessandro Message-ID: Date: Fri, 14 Feb 2020 12:24:52 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 2/14/2020 10:43 AM, Madhuparna Bhowmik wrote: > > > On Wed, Jan 15, 2020 at 12:05 AM > wrote: > > From: Dennis Dalessandro > > > On 1/14/2020 12:00 PM, Dennis Dalessandro wrote: > > On 1/14/2020 11:57 AM, Jason Gunthorpe wrote: > >> On Tue, Jan 14, 2020 at 09:53:45PM +0530, > >> madhuparnabhowmik04@gmail.com > wrote: > >>> From: Madhuparna Bhowmik > > >>> > >>> list_for_each_entry_rcu has built-in RCU and lock checking. > >>> Pass cond argument to list_for_each_entry_rcu. > >>> > >>> Signed-off-by: Madhuparna Bhowmik > > > >>>   drivers/infiniband/hw/hfi1/verbs.c | 2 +- > >>>   1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/infiniband/hw/hfi1/verbs.c > >>> b/drivers/infiniband/hw/hfi1/verbs.c > >>> index 089e201d7550..22f2d4fd2577 100644 > >>> +++ b/drivers/infiniband/hw/hfi1/verbs.c > >>> @@ -515,7 +515,7 @@ static inline void hfi1_handle_packet(struct > >>> hfi1_packet *packet, > >>>                          opa_get_lid(packet->dlid, 9B)); > >>>           if (!mcast) > >>>               goto drop; > >>> -        list_for_each_entry_rcu(p, &mcast->qp_list, list) { > >>> +        list_for_each_entry_rcu(p, &mcast->qp_list, list, > >>> lockdep_is_held(&(ibp->rvp.lock))) { > >> > >> Okay, this looks reasonable > >> > >> Mike, Dennis, is this the right lock to test? > >> > > > > I'm looking at that right now actually, I don't think this is > correct. > > Wanted to talk to Mike before I send a response though. > > > > -Denny > > That's definitely going to throw a ton of lock dep messages. It's not > really the right lock either. Instead what we probably need to do is > what we do in the non-multicast part of the code and take the > rcu_read_lock(). > > I'd say hold off on this and we'll fix it right. Same goes for the > qib one. > > Alright, thank you for reviewing. > > The rdmavt one though looks to be OK. I'll give it a test. > > Hi, > I just wanted to follow up on this. > Any updates? > Also, is the bug fixed now? > > Thank you, > Madhuparna > > Thank you, > Madhuparna > > -Denny > I've got a patch going through internal discussion and testing for adding rcu read locking. The RDMAVT patch, I was OK with going in, I guess I just mentioned that in a reply rather than adding an RB tag. Let me go ahead and do that. -Denny 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 683D1C2BA83 for ; Fri, 14 Feb 2020 17:25:02 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 3C8982168B for ; Fri, 14 Feb 2020 17:25:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C8982168B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-kernel-mentees-bounces@lists.linuxfoundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 12B94868C4; Fri, 14 Feb 2020 17:25:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id lNgrG6ac5fjS; Fri, 14 Feb 2020 17:25:01 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 8B468868BD; Fri, 14 Feb 2020 17:25:01 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 73091C0881; Fri, 14 Feb 2020 17:25:01 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 40599C0177 for ; Fri, 14 Feb 2020 17:24:59 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 39B8C8820A for ; Fri, 14 Feb 2020 17:24:59 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id geFtkNQmbQBH for ; Fri, 14 Feb 2020 17:24:57 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by hemlock.osuosl.org (Postfix) with ESMTPS id 3D61C8820C for ; Fri, 14 Feb 2020 17:24:57 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Feb 2020 09:24:57 -0800 X-IronPort-AV: E=Sophos;i="5.70,441,1574150400"; d="scan'208";a="223081205" Received: from ddalessa-mobl.amr.corp.intel.com (HELO [10.254.204.146]) ([10.254.204.146]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 14 Feb 2020 09:24:54 -0800 To: Madhuparna Bhowmik , Jason Gunthorpe References: <20200114162345.19995-1-madhuparnabhowmik04@gmail.com> <20200114165740.GB22037@ziepe.ca> <74adec84-ec5b-ea1b-7adf-3f8608838259@intel.com> <25133367-6544-d0af-ae30-5178909748b1@intel.com> From: Dennis Dalessandro Message-ID: Date: Fri, 14 Feb 2020 12:24:52 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: mike.marciniszyn@intel.com, "Paul E. McKenney" , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, Joel Fernandes , linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [Linux-kernel-mentees] [PATCH 1/3] infiniband: hw: hfi1: verbs.c: Use built-in RCU list checking X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" T24gMi8xNC8yMDIwIDEwOjQzIEFNLCBNYWRodXBhcm5hIEJob3dtaWsgd3JvdGU6Cj4gCj4gCj4g T24gV2VkLCBKYW4gMTUsIDIwMjAgYXQgMTI6MDUgQU0gPG1hZGh1cGFybmFiaG93bWlrMDRAZ21h aWwuY29tIAo+IDxtYWlsdG86bWFkaHVwYXJuYWJob3dtaWswNEBnbWFpbC5jb20+PiB3cm90ZToK PiAKPiAgICAgRnJvbTogRGVubmlzIERhbGVzc2FuZHJvIDxkZW5uaXMuZGFsZXNzYW5kcm9AaW50 ZWwuY29tCj4gICAgIDxtYWlsdG86ZGVubmlzLmRhbGVzc2FuZHJvQGludGVsLmNvbT4+Cj4gCj4g ICAgIE9uIDEvMTQvMjAyMCAxMjowMCBQTSwgRGVubmlzIERhbGVzc2FuZHJvIHdyb3RlOgo+ICAg ICAgPiBPbiAxLzE0LzIwMjAgMTE6NTcgQU0sIEphc29uIEd1bnRob3JwZSB3cm90ZToKPiAgICAg ID4+IE9uIFR1ZSwgSmFuIDE0LCAyMDIwIGF0IDA5OjUzOjQ1UE0gKzA1MzAsCj4gICAgICA+PiBt YWRodXBhcm5hYmhvd21pazA0QGdtYWlsLmNvbQo+ICAgICA8bWFpbHRvOm1hZGh1cGFybmFiaG93 bWlrMDRAZ21haWwuY29tPiB3cm90ZToKPiAgICAgID4+PiBGcm9tOiBNYWRodXBhcm5hIEJob3dt aWsgPG1hZGh1cGFybmFiaG93bWlrMDRAZ21haWwuY29tCj4gICAgIDxtYWlsdG86bWFkaHVwYXJu YWJob3dtaWswNEBnbWFpbC5jb20+Pgo+ICAgICAgPj4+Cj4gICAgICA+Pj4gbGlzdF9mb3JfZWFj aF9lbnRyeV9yY3UgaGFzIGJ1aWx0LWluIFJDVSBhbmQgbG9jayBjaGVja2luZy4KPiAgICAgID4+ PiBQYXNzIGNvbmQgYXJndW1lbnQgdG8gbGlzdF9mb3JfZWFjaF9lbnRyeV9yY3UuCj4gICAgICA+ Pj4KPiAgICAgID4+PiBTaWduZWQtb2ZmLWJ5OiBNYWRodXBhcm5hIEJob3dtaWsKPiAgICAgPG1h ZGh1cGFybmFiaG93bWlrMDRAZ21haWwuY29tIDxtYWlsdG86bWFkaHVwYXJuYWJob3dtaWswNEBn bWFpbC5jb20+Pgo+ICAgICAgPj4+IMKgIGRyaXZlcnMvaW5maW5pYmFuZC9ody9oZmkxL3ZlcmJz LmMgfCAyICstCj4gICAgICA+Pj4gwqAgMSBmaWxlIGNoYW5nZWQsIDEgaW5zZXJ0aW9uKCspLCAx IGRlbGV0aW9uKC0pCj4gICAgICA+Pj4KPiAgICAgID4+PiBkaWZmIC0tZ2l0IGEvZHJpdmVycy9p bmZpbmliYW5kL2h3L2hmaTEvdmVyYnMuYwo+ICAgICAgPj4+IGIvZHJpdmVycy9pbmZpbmliYW5k L2h3L2hmaTEvdmVyYnMuYwo+ICAgICAgPj4+IGluZGV4IDA4OWUyMDFkNzU1MC4uMjJmMmQ0ZmQy NTc3IDEwMDY0NAo+ICAgICAgPj4+ICsrKyBiL2RyaXZlcnMvaW5maW5pYmFuZC9ody9oZmkxL3Zl cmJzLmMKPiAgICAgID4+PiBAQCAtNTE1LDcgKzUxNSw3IEBAIHN0YXRpYyBpbmxpbmUgdm9pZCBo ZmkxX2hhbmRsZV9wYWNrZXQoc3RydWN0Cj4gICAgICA+Pj4gaGZpMV9wYWNrZXQgKnBhY2tldCwK PiAgICAgID4+PiDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKg wqAgb3BhX2dldF9saWQocGFja2V0LT5kbGlkLCA5QikpOwo+ICAgICAgPj4+IMKgwqDCoMKgwqDC oMKgwqDCoCBpZiAoIW1jYXN0KQo+ICAgICAgPj4+IMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKg IGdvdG8gZHJvcDsKPiAgICAgID4+PiAtwqDCoMKgwqDCoMKgwqAgbGlzdF9mb3JfZWFjaF9lbnRy eV9yY3UocCwgJm1jYXN0LT5xcF9saXN0LCBsaXN0KSB7Cj4gICAgICA+Pj4gK8KgwqDCoMKgwqDC oMKgIGxpc3RfZm9yX2VhY2hfZW50cnlfcmN1KHAsICZtY2FzdC0+cXBfbGlzdCwgbGlzdCwKPiAg ICAgID4+PiBsb2NrZGVwX2lzX2hlbGQoJihpYnAtPnJ2cC5sb2NrKSkpIHsKPiAgICAgID4+Cj4g ICAgICA+PiBPa2F5LCB0aGlzIGxvb2tzIHJlYXNvbmFibGUKPiAgICAgID4+Cj4gICAgICA+PiBN aWtlLCBEZW5uaXMsIGlzIHRoaXMgdGhlIHJpZ2h0IGxvY2sgdG8gdGVzdD8KPiAgICAgID4+Cj4g ICAgICA+Cj4gICAgICA+IEknbSBsb29raW5nIGF0IHRoYXQgcmlnaHQgbm93IGFjdHVhbGx5LCBJ IGRvbid0IHRoaW5rIHRoaXMgaXMKPiAgICAgY29ycmVjdC4KPiAgICAgID4gV2FudGVkIHRvIHRh bGsgdG8gTWlrZSBiZWZvcmUgSSBzZW5kIGEgcmVzcG9uc2UgdGhvdWdoLgo+ICAgICAgPgo+ICAg ICAgPiAtRGVubnkKPiAKPiAgICAgVGhhdCdzIGRlZmluaXRlbHkgZ29pbmcgdG8gdGhyb3cgYSB0 b24gb2YgbG9jayBkZXAgbWVzc2FnZXMuIEl0J3Mgbm90Cj4gICAgIHJlYWxseSB0aGUgcmlnaHQg bG9jayBlaXRoZXIuIEluc3RlYWQgd2hhdCB3ZSBwcm9iYWJseSBuZWVkIHRvIGRvIGlzCj4gICAg IHdoYXQgd2UgZG8gaW4gdGhlIG5vbi1tdWx0aWNhc3QgcGFydCBvZiB0aGUgY29kZSBhbmQgdGFr ZSB0aGUKPiAgICAgcmN1X3JlYWRfbG9jaygpLgo+IAo+ICAgICBJJ2Qgc2F5IGhvbGQgb2ZmIG9u IHRoaXMgYW5kIHdlJ2xsIGZpeCBpdCByaWdodC4gU2FtZSBnb2VzIGZvciB0aGUKPiAgICAgcWli IG9uZS4KPiAKPiAgICAgQWxyaWdodCwgdGhhbmsgeW91IGZvciByZXZpZXdpbmcuCj4gCj4gICAg IFRoZSByZG1hdnQgb25lIHRob3VnaCBsb29rcyB0byBiZSBPSy4gSSdsbCBnaXZlIGl0IGEgdGVz dC4KPiAKPiBIaSwKPiBJIGp1c3Qgd2FudGVkIHRvIGZvbGxvdyB1cCBvbiB0aGlzLgo+IEFueSB1 cGRhdGVzPwo+IEFsc28sIGlzIHRoZSBidWcgZml4ZWQgbm93Pwo+IAo+IFRoYW5rIHlvdSwKPiBN YWRodXBhcm5hCj4gCj4gICAgIFRoYW5rIHlvdSwKPiAgICAgTWFkaHVwYXJuYQo+IAo+ICAgICAt RGVubnkKPiAKCkkndmUgZ290IGEgcGF0Y2ggZ29pbmcgdGhyb3VnaCBpbnRlcm5hbCBkaXNjdXNz aW9uIGFuZCB0ZXN0aW5nIGZvciAKYWRkaW5nIHJjdSByZWFkIGxvY2tpbmcuCgpUaGUgUkRNQVZU IHBhdGNoLCBJIHdhcyBPSyB3aXRoIGdvaW5nIGluLCBJIGd1ZXNzIEkganVzdCBtZW50aW9uZWQg dGhhdCAKaW4gYSByZXBseSByYXRoZXIgdGhhbiBhZGRpbmcgYW4gUkIgdGFnLiBMZXQgbWUgZ28g YWhlYWQgYW5kIGRvIHRoYXQuCgotRGVubnkKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX18KTGludXgta2VybmVsLW1lbnRlZXMgbWFpbGluZyBsaXN0CkxpbnV4 LWtlcm5lbC1tZW50ZWVzQGxpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcKaHR0cHM6Ly9saXN0cy5s aW51eGZvdW5kYXRpb24ub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgta2VybmVsLW1lbnRlZXMK