Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   "Zhang, Qiang1" <qiang1.zhang@intel.com>
To:     "Zhang, Qiang1" <qiang1.zhang@intel.com>,
        "paulmck@kernel.org" <paulmck@kernel.org>,
        "frederic@kernel.org" <frederic@kernel.org>
CC:     "rcu@vger.kernel.org" <rcu@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] rcu: Fix incorrect judgment condition in
 show_rcu_nocb_state()
Thread-Topic: [PATCH] rcu: Fix incorrect judgment condition in
 show_rcu_nocb_state()
Thread-Index: AQHYb+hwe8ZGESsVvU2EbYC8INN+sa044Rog
Date:   Tue, 31 May 2022 11:24:55 +0000
Message-ID: <PH0PR11MB5880D97F865580DFB6F12A9DDADC9@PH0PR11MB5880.namprd11.prod.outlook.com>
References: <20220525033430.1953349-1-qiang1.zhang@intel.com>
In-Reply-To: <20220525033430.1953349-1-qiang1.zhang@intel.com>
Accept-Language: en-US
Content-Language: en-US
dlp-product: dlpe-windows
dlp-version: 11.6.500.17
dlp-reaction: no-action
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?/yU7YnFnv1i7Kj+OZ99r+BooUuPyGgK92/XCF99vMmEmUw/Pmn83UVGKfi48?=
 =?us-ascii?Q?v2uTUJL7ksFDk4vn8q022kTGrGckvlo3+XPs8pnAuiu+NTYk1UM3HDZ/If9h?=
 =?us-ascii?Q?CptoAzrOD7GXfSPngMMVXeQuGtTcVzPmnANU7b9f7IkFbwn78IXi2hrr5Cjt?=
 =?us-ascii?Q?C/CyCa3GFe/+tdLd0Z4Ov39sHL//N5DRFdF9hvEjgxGrmOZHif8+IfvBsUbM?=
 =?us-ascii?Q?T42ztgMHJMsfNlZu9Nb6trfXcnZZ5vq8ZNDKm47rrFdlef2qZf4aMpMwfMw/?=
 =?us-ascii?Q?Xg4Kpl9Cgwc1LQmfDe4dLhUrGag37sgdz16hH9EtFSqmP1bj9sGSRBxO9goS?=
 =?us-ascii?Q?azLPG9nXDFMUlVyUbQyPfTrOGMIYw8cV/pYG52HI7eB9pM5Ip4BUeppMsLei?=
 =?us-ascii?Q?GvKHKZKq2giO1Dhb5Dzxxg3/UhBM5rzkDlPBALyuXpTgpdpwj5+mNIZN9PZO?=
 =?us-ascii?Q?+/M9X9B+fue7Bv0SdXlpRL6+QmLM3a7TsGDdg7CEzznvvDQNEVducfvHAPwm?=
 =?us-ascii?Q?EAihor32ZsEqp1EykjCx1NUdKxgosUHR3eyqdPxcNeFfOv8WFpeFHO/kRqrg?=
 =?us-ascii?Q?aKD9pkD/gjgKzSwRVXXAGo+4tu5Rm4hydnC9gu7JXrOH2kOoO8hiGdhnzPxJ?=
 =?us-ascii?Q?CT9+aHJrl0pnFwaXZyKEqglM9uTwUvvG2Am33jZO07dJQv2KLOPqvKl5XfDx?=
 =?us-ascii?Q?Yjr96ON4eEu/kyu0rD5UolyGe3dFPFhGU+opOj37KdaRoWCAZ4FVM1KoiAdE?=
 =?us-ascii?Q?VenYhY3NUm99EJS/1BTRy+1M6m2DbTAEUp8mbG0+KFzVOA2wyF83+Uji/7fw?=
 =?us-ascii?Q?MDCKiXmjpw90BuqafWHSEXuT3MyYU+uEpbPL6Ar+Rn3rY0yPlgDMV75NLLuV?=
 =?us-ascii?Q?XN0+1QeAqLWpUcUoVzJ86Z36bPksOcGqdsxe+Hs3ifT348GhiXGSTIbhgu5u?=
 =?us-ascii?Q?I7OTCFGbw48mRUqb4XvZgeRgoyL+k10UVjuHLtEUUWVyTtFatjSHwF/EYTZv?=
 =?us-ascii?Q?9ADCgHx6QjKYIAX8dP4LsL6+oVOKERNVIo+9ZjkbJA6pruHtkunifB3BMfjK?=
 =?us-ascii?Q?qVl+vIYn44mD3LrRSQAdVL6e+dUiByx2VK4Bj4BHYDwG7zg9q0zbeL//WMQQ?=
 =?us-ascii?Q?z8AauLSiFZG1PX/3cnpFjcCNb0AhpfAn35bBQWZDrqhk576Ia+NwlazMVNA8?=
 =?us-ascii?Q?B16ptkyX08nRHQMiA9tpPBW7VAdmKVBZx505cYOkJMvCqneZLBol4N2JyrX+?=
 =?us-ascii?Q?5muw5MVhFhw5QvT9OAnW1qsb5tuO9slqutErPWTKqNC3y0PVvJBYsBtpPPrv?=
 =?us-ascii?Q?9LgXEAHWbZ1kL0fDMxgPmdDGvDwbaFcz8s/iff+5JW2C5+fJs2uotMva3sbV?=
 =?us-ascii?Q?r9zqnVX6x22ywzcHAamMVotG9liNwKm4mZeHIsK2qMN5hq/WysMw/cI38HKl?=
 =?us-ascii?Q?FOVdhcavciaRtzJ+SLaZArpMY+l/GgY+3RVb0fO05ZLsmViWYoeWbZcKmTyX?=
 =?us-ascii?Q?o7QQ3iiLLPAg/lcu9BIZkNWMWlvZXNI8tzJAnqcCKdFXNM84mN0wGPFZAAcz?=
 =?us-ascii?Q?LOHagY3tiq8C5oBeVh1Hfv8CnJLCRi16fcctJUZMHC0iQw49WiZ5CQZGk8/m?=
 =?us-ascii?Q?HrPdkydKYNyQ+Id/gf9CpeyfuimT6zQzeudvb3+Rt1s1KgzAO895YRVDEqUh?=
 =?us-ascii?Q?Jr0D623whEaHcr9HVLjWy84RzJi1E0HDYDWC1U5H3zq4qmFPllJpFmbF5es7?=
 =?us-ascii?Q?VMiErW4hUw=3D=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: PH0PR11MB5880.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 8b6fd156-46f5-4d7a-bede-08da42f83046
X-MS-Exchange-CrossTenant-originalarrivaltime: 31 May 2022 11:24:55.5455
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: ZzJEU9zpbBpehILqxSLcQDqp+9GcyTHi5DGdv9I8S8QMSprEb0ACbni4vQ4/Btp5zy92glJdLA1B+1ExhX4rJg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR11MB3771
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
	DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,RDNS_NONE,SPF_HELO_NONE,T_SCC_BODY_TEXT_LINE
	autolearn=unavailable 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-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi  Frederic

Friendly ping.

Thanks
Zqiang


When check the 'rdp->nocb_cb_kthread' tasks exists, if is true, however
the output is the cpu where 'rdp->nocb_gp_kthread' is located. this
ensure that the tasks in the judgment condition and the tasks of the
cpu where the output tasks are located are the same tasks.

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
---
 kernel/rcu/tree_nocb.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index fa8e4f82e60c..f4ee81d119c8 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1438,8 +1438,8 @@ static void show_rcu_nocb_gp_state(struct rcu_data *r=
dp)
 		(long)rdp->nocb_gp_seq,
 		rnp->grplo, rnp->grphi, READ_ONCE(rdp->nocb_gp_loops),
 		rdp->nocb_gp_kthread ? task_state_to_char(rdp->nocb_gp_kthread) : '.',
-		rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1,
-		show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread));
+		rdp->nocb_gp_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1,
+		show_rcu_should_be_on_cpu(rdp->nocb_gp_kthread));
 }
=20
 /* Dump out nocb kthread state for the specified rcu_data structure. */
@@ -1483,7 +1483,7 @@ static void show_rcu_nocb_state(struct rcu_data *rdp)
 		".B"[!!rcu_cblist_n_cbs(&rdp->nocb_bypass)],
 		rcu_segcblist_n_cbs(&rdp->cblist),
 		rdp->nocb_cb_kthread ? task_state_to_char(rdp->nocb_cb_kthread) : '.',
-		rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1,
+		rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_cb_kthread) : -1,
 		show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread));
=20
 	/* It is OK for GP kthreads to have GP state. */
--=20
2.25.1