Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 10 Nov 2022 17:05:09 -0500
From:   Daniel Jordan <daniel.m.jordan@oracle.com>
To:     Nicolai Stange <nstange@suse.de>
Cc:     Steffen Klassert <steffen.klassert@secunet.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Martin Doucha <mdoucha@suse.cz>, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] padata: make padata_free_shell() to respect pd's
 ->refcnt
Message-ID: <20221110220509.cdymlc5lyrk7wsah@parnassus.localdomain>
References: <20221019083708.27138-1-nstange@suse.de>
 <20221019083708.27138-3-nstange@suse.de>
 <20221028143546.3xc6rnfkfcml373c@parnassus.localdomain>
 <87educb7rm.fsf@suse.de>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87educb7rm.fsf@suse.de>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?WgZEKTNsRNu1IWFVo+jDqh5LNXST3BVZ97yl3j6X3bFK4LSBrCIezDU1KXWg?=
 =?us-ascii?Q?rIL/g3AOsLA8I7dQncggWnurhR3bCFDmjBDUXBOnxpoOFkdQKyhufS+94+UF?=
 =?us-ascii?Q?eT5fJgZ7Bel5ZEb6G2Dohsy943Qc2e6bdwuaEPq7wK95L9cl88iIw7I8W1lt?=
 =?us-ascii?Q?WOnx1JVPa8C1aYxvUnJYUazSDmBPnpS5wOziXJhD0tyGWHvNNkfzs3J3TfUV?=
 =?us-ascii?Q?4GDY4y+So/bmWlpmOhlt2Q7m6JQ2uzZrwmFDvdDX+pFK6ZegjtOCKOJ1EF1F?=
 =?us-ascii?Q?9d9tFw2EG6u/lg2uKcsT9V7rYz2MFqdwkpuW5TmrvXmUyEI58fACh9FNPlty?=
 =?us-ascii?Q?iYY3hCQpjVuLQqb8yP0+WLPt6fcJ/5URp2wcI61ih56EegJXuucBHs+jqEqJ?=
 =?us-ascii?Q?940tqr3oV3tiXnMCgKIPcgppEkQSDwmTZ/MM9WBRDFqGKbI41YbL6ZmEyO4r?=
 =?us-ascii?Q?SCQh4+Nz6OBlifMjk0x2ghVttjYnk37H5CYyyvDuaQWJc/iBnACh2jZzC5aR?=
 =?us-ascii?Q?/Lw3eX2TCI65wqNgT7tUwJI769Fo3jl2QYq9+jzKVMRvAr2UdhH06P26SBBt?=
 =?us-ascii?Q?LDsVTmC8IXgkUrfLW1e4BixREuN0KFNzp2aMrCW+wC818P/nKNiskbmG6Ird?=
 =?us-ascii?Q?01kLst4w+54hc4I8zNGP5bUBB4+S20c/e+Sxsf3e+k/XF6A61RisdYwn316/?=
 =?us-ascii?Q?epgB9MrmSVIv9iXVVkIN46bcdwt3FwtdAQ9WANf4dhtZP/Trcl3CvZKZiNjf?=
 =?us-ascii?Q?esAIV/nKs3HdT4YqSEr09FtcS5JYnp/NmPsI+vy83RuzhROjMRR/uzn3B2Y2?=
 =?us-ascii?Q?PPIVmPcwvIjCnctY75yh3aJ5PjsRCekAMiwfLAidlZg9TC1F3FABi1AyCGv5?=
 =?us-ascii?Q?iZwRfOJIzYZ5lcNo68pKfNq9EdOagDRK41iXXxfd3TFU44a3SzN4y46JnTDn?=
 =?us-ascii?Q?sJ1t2JGKwFBdowyvMWHRY0JPf2S2X23rbQOUIq2M1kjWaXMxPCkAzjvmZWwF?=
 =?us-ascii?Q?tmmZMpScruhioxnEPVwlbygPWcnJnNfqEpVqLdAI+KHGlHX22w8lwnaY9ir/?=
 =?us-ascii?Q?V/4LQEg5Y0PvcUXHl6eciS+3PCl0AQ/hjPd2ijaftcDB21TJAEzYUOnNQ99V?=
 =?us-ascii?Q?MFlwjfDMXOWCL5GLUxaBKfn6Grxt8vO65mtwjR9BEsh+gVj2fwLAz9xO2ctH?=
 =?us-ascii?Q?6dVSXbyDuzJWUlSpYnwA4D96QEy/G222mFO9vLqRktH8gSi6zdqUIzD9j8k9?=
 =?us-ascii?Q?jk1xOV8X/lyp8T1I32kf6A7nFT1nL9tCCwLjZa46rvdDnzBKfc4QKayqYN7x?=
 =?us-ascii?Q?xYSRpEAJxEUdM2IbzLr3vAdnqYcDvCuFfI2C4WDV9eDs0pagwWK/LRjjx02X?=
 =?us-ascii?Q?D/D/OJUqMatoqis6fata9WH16dEQ9UakIUbeTRp3cuovEYNAeQ5JaBaKL9nb?=
 =?us-ascii?Q?Ec2YsKQl+xJJetOQSMWJjgb1hmjFpdjQU5512Rj6ZTbU/1hITGr63xE39d+5?=
 =?us-ascii?Q?+Es6ExcS00mSPL7z40Tp9kcsHkA+T4xH5xiDkx/VTkGDcmG6q3hz/Hbyg56N?=
 =?us-ascii?Q?lvKwJ40ebD09iXNpQOPnW4dYBHvF1rFxXST+RrW/EZmfOTYS77U9dXZsBfvH?=
 =?us-ascii?Q?9g=3D=3D?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 44282508-de08-4f30-307b-08dac367a473
X-MS-Exchange-CrossTenant-AuthSource: SA1PR10MB5711.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Nov 2022 22:05:13.6593
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: imc8rfQIYJt+reQJZ0tEVbRWMkhOhgE/COwG8GO410phZhOFuME0TH8CdpPTBs2IJNWoZb/wdFe28mKI+5RNQJH58E8N9z9vsRfZ0QlWsjU=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BLAPR10MB5074
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1
 definitions=2022-11-10_14,2022-11-09_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 adultscore=0 mlxscore=0
 suspectscore=0 spamscore=0 malwarescore=0 bulkscore=0 phishscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000
 definitions=main-2211100155
X-Proofpoint-ORIG-GUID: iJke6fu0Gmf01f94CmwDx6H9ACB2892P
X-Proofpoint-GUID: iJke6fu0Gmf01f94CmwDx6H9ACB2892P
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-crypto.vger.kernel.org>
X-Mailing-List: linux-crypto@vger.kernel.org

On Wed, Nov 09, 2022 at 02:02:37PM +0100, Nicolai Stange wrote:
> Daniel Jordan <daniel.m.jordan@oracle.com> writes:
> 
> > On Wed, Oct 19, 2022 at 10:37:05AM +0200, Nicolai Stange wrote:
> >> 
> >> Fixes: 07928d9bfc81 ("padata: Remove broken queue flushing")
> >
> > It looks like this issue goes back to the first padata commit.  For
> > instance, pd->refcnt goes to zero after the last _priv is serialized,
> > padata_free is called in another task, and a particularly sluggish
> > padata_reorder call touches pd after.
> >
> > So wouldn't it be
> >
> > Fixes: 16295bec6398 ("padata: Generic parallelization/serialization interface")
> 
> I chose 07928d9bfc81 ("padata: Remove broken queue flushing"), because
> that one reads like it fixed a couple of much more severe padata
> lifetime issues, it only missed the relatively minor one addressed here,
> in a sense.
> 
> Or to put it the other way around: if one were to backport this patch
> here, 07928d9bfc81 should probably get picked first, I think.
> 
> But I'd be fine with any Fixes tag, of course, I don't have a strong
> opinion on this matter.

Ok, makes sense, your Fixes is fine then.  Please put that justification
in the changelog for the next version.