From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751952AbdJBQBl (ORCPT ); Mon, 2 Oct 2017 12:01:41 -0400 Received: from esa1.hgst.iphmx.com ([68.232.141.245]:38842 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751785AbdJBQBj (ORCPT ); Mon, 2 Oct 2017 12:01:39 -0400 X-IronPort-AV: E=Sophos;i="5.42,470,1500912000"; d="scan'208";a="158313189" From: Bart Van Assche To: "linux-scsi@vger.kernel.org" , "hch@infradead.org" , "jejb@linux.vnet.ibm.com" , "linux-block@vger.kernel.org" , "axboe@fb.com" , "ming.lei@redhat.com" , "martin.petersen@oracle.com" CC: Bart Van Assche , "martin@lichtvoll.de" , "linux-kernel@vger.kernel.org" , "jthumshirn@suse.de" , "oleksandr@natalenko.name" , "hare@suse.com" , "cavery@redhat.com" Subject: Re: [PATCH V7 2/6] block: tracking request allocation with q_usage_counter Thread-Topic: [PATCH V7 2/6] block: tracking request allocation with q_usage_counter Thread-Index: AQHTObMph4iywGi0vEqn1bLE99zsn6LQvAiA Date: Mon, 2 Oct 2017 16:01:34 +0000 Message-ID: <1506960093.3368.21.camel@wdc.com> References: <20170930061214.10622-1-ming.lei@redhat.com> <20170930061214.10622-3-ming.lei@redhat.com> In-Reply-To: <20170930061214.10622-3-ming.lei@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=Bart.VanAssche@wdc.com; x-originating-ip: [63.163.107.100] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;CY1PR0401MB1533;20:ZnOg0dPEDUgTLnErw57GwbvdvLEqr6KIed04Bp3dWYDqEdkfm8+AkXZTuud2f0VefHYnEDbqIwuoCzZOGQ+i1Vm2AMC7XdoJs3GdN+3EWl2auTbg1tHHASg+0rMrAb0pp26YqCp5f7SzG+Rw773k/rkaAlU6/Fqb1PNX25rBV1U= x-ms-exchange-antispam-srfa-diagnostics: SSOS;SSOR; x-ms-office365-filtering-correlation-id: b4ce6db7-4b32-469e-8177-08d509aedb40 x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(2017030254152)(48565401081)(2017052603199)(201703131423075)(201703031133081)(201702281549075);SRVR:CY1PR0401MB1533; x-ms-traffictypediagnostic: CY1PR0401MB1533: wdcipoutbound: EOP-TRUE x-exchange-antispam-report-test: UriScan:; x-microsoft-antispam-prvs: x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(100000700101)(100105000095)(100000701101)(100105300095)(100000702101)(100105100095)(6040450)(2401047)(5005006)(8121501046)(3002001)(93006095)(93001095)(100000703101)(100105400095)(10201501046)(6055026)(6041248)(20161123564025)(201703131423075)(201702281528075)(201703061421075)(201703061406153)(20161123558100)(20161123555025)(20161123560025)(20161123562025)(6072148)(201708071742011)(100000704101)(100105200095)(100000705101)(100105500095);SRVR:CY1PR0401MB1533;BCL:0;PCL:0;RULEID:(100000800101)(100110000095)(100000801101)(100110300095)(100000802101)(100110100095)(100000803101)(100110400095)(100000804101)(100110200095)(100000805101)(100110500095);SRVR:CY1PR0401MB1533; x-forefront-prvs: 0448A97BF2 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(376002)(39860400002)(346002)(199003)(377424004)(189002)(24454002)(72206003)(305945005)(478600001)(4326008)(68736007)(50986999)(76176999)(54356999)(101416001)(25786009)(6246003)(14454004)(8936002)(110136005)(54906003)(102836003)(6116002)(3846002)(2501003)(99286003)(81156014)(81166006)(53936002)(97736004)(8676002)(7736002)(6512007)(316002)(3660700001)(86362001)(229853002)(36756003)(3280700002)(2201001)(106356001)(2906002)(7416002)(33646002)(66066001)(105586002)(103116003)(189998001)(2900100001)(5660300001)(6436002)(6506006)(2950100002)(6486002)(77096006);DIR:OUT;SFP:1102;SCL:1;SRVR:CY1PR0401MB1533;H:CY1PR0401MB1536.namprd04.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: <7FF5B73D0B66DC47B4ABED19655D30E2@namprd04.prod.outlook.com> MIME-Version: 1.0 X-OriginatorOrg: wdc.com X-MS-Exchange-CrossTenant-originalarrivaltime: 02 Oct 2017 16:01:34.8627 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b61c8803-16f3-4c35-9b17-6f65f441df86 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR0401MB1533 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id v92G1jZN030939 On Sat, 2017-09-30 at 14:12 +0800, Ming Lei wrote: > @@ -1395,16 +1401,21 @@ static struct request *blk_old_get_request(struct request_queue *q, > unsigned int op, gfp_t gfp_mask) > { > struct request *rq; > + int ret = 0; > > WARN_ON_ONCE(q->mq_ops); > > /* create ioc upfront */ > create_io_context(gfp_mask, q->node); > > + ret = blk_queue_enter(q, !(gfp_mask & __GFP_DIRECT_RECLAIM)); > + if (ret) > + return ERR_PTR(ret); Can the above blk_queue_enter() call block if the REQ_NOWAIT flag has been set in the op argument and e.g. gfp_mask == GFP_KERNEL? If so, isn't that a bug? Bart.