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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9D9DBC32753 for ; Wed, 14 Aug 2019 15:05:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B5892063F for ; Wed, 14 Aug 2019 15:05:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726551AbfHNPFI (ORCPT ); Wed, 14 Aug 2019 11:05:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36446 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726509AbfHNPFI (ORCPT ); Wed, 14 Aug 2019 11:05:08 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 308798E5AA; Wed, 14 Aug 2019 15:05:08 +0000 (UTC) Received: from linux-ws.nc.xsintricity.com (ovpn-112-57.rdu2.redhat.com [10.10.112.57]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D95D688B2C; Wed, 14 Aug 2019 15:05:06 +0000 (UTC) Message-ID: Subject: Re: [PATCH for-next 3/9] RDMA/hns: Completely release qp resources when hw err From: Doug Ledford To: Yangyang Li , Lijun Ou , jgg@ziepe.ca Cc: leon@kernel.org, linux-rdma@vger.kernel.org, linuxarm@huawei.com Date: Wed, 14 Aug 2019 11:05:04 -0400 In-Reply-To: <0d325f78-a929-f088-cc29-e2c7af98fd40@huawei.com> References: <1565343666-73193-1-git-send-email-oulijun@huawei.com> <1565343666-73193-4-git-send-email-oulijun@huawei.com> <0d325f78-a929-f088-cc29-e2c7af98fd40@huawei.com> Organization: Red Hat, Inc. Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-r0AoODz9O6/ASb6poCGk" User-Agent: Evolution 3.32.4 (3.32.4-1.fc30) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 14 Aug 2019 15:05:08 +0000 (UTC) Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org --=-r0AoODz9O6/ASb6poCGk Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2019-08-14 at 14:02 +0800, Yangyang Li wrote: > > I don't know your hardware, but this patch sounds wrong/dangerous to > > me. > > As long as the resources this card might access are allocated by the > > kernel, you can't get random data corruption by the card writing to > > memory used elsewhere in the kernel. So if your card is not > > responding > > to your requests to free the resources, it would seem safer to leak > > those resources permanently than to free them and risk the card > > coming > > back to life long enough to corrupt memory reallocated to some other > > task. > >=20 > > Only if you can guarantee me that there is no way your commands to > > the > > card will fail and then the card start working again later would I > > consider this patch safe. And if it's possible for the card to hang > > like this, should that be triggering a reset of the device? > >=20 >=20 > Thanks for your suggestion, I agree with you, it would seem safer to > leak > those resources permanently than to free them. I will abandon this > change > and consider cleaning up these leaked resources during uninstallation > or reset. Ok, patch dropped from patchworks, thanks. --=20 Doug Ledford GPG KeyID: B826A3330E572FDD Fingerprint =3D AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD --=-r0AoODz9O6/ASb6poCGk Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEErmsb2hIrI7QmWxJ0uCajMw5XL90FAl1UIyAACgkQuCajMw5X L901PBAApBCQCDEYWdUDb4rWUSmsnvCgU8VevmSQgtuGKpiE2RBW2QlGDqxRSJf+ 4S9v/vvLSHq9Qzg0euM3S8zZuTfUtqWwEgpfaTik572ou32uWv6lPirgoOatKdcL VHtNZCy2Yj88gDewxUvCqxTA1e1O9fYou9EN7qbKmuT4UDaGgsX9zEib6lcE6nE/ Vfd5MJBXWzkZCcWsvE4PPE1ATyskOEut2Fd4Q1NdO4GzWz8M/l/DxDnW9Jx19XQe WM4AvI3OybE9s+Xf2yEWhSb/gdkOqt1f9sZCnMJQtSCH7HoTHIt6jV6uDoUE+lc3 H9qgSMBSBkEUS6CFKVjvaPMYwn/04P1yxexE6d2Yj9Oq66QT0nFsWWrWzH/8JH69 HIFzKjR4ekiwyaM6S7MKiY1xOTh1IIrRhYiubY1fdBPSysBDwxTO13SzWqN0qfhV P8MJjYDSU0+HzhjP8rbB1CuRvwZoqypmNeDgdUwhWkbY2U+n0X5SZml61R9k4u37 FzdaNCsT8+Y2WbKYCZUvKJmoS3cbFZk/gJBEuDePtO8B/gFoyXnMn9GehcS+Gdj8 tfcsLgmjVxxyZnKNrwnA26v3pN1MZDOPQ8jWoMKMK2xDs5X5NwR1w/KYPQ7byWwu +1vyKtP8DYgrkn56ErJGc6/VFBYE2ob/oeoRrg1DTkK97xjlsk8= =JlS9 -----END PGP SIGNATURE----- --=-r0AoODz9O6/ASb6poCGk--