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Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Subject: Re: [dm-devel] [PATCH] blk-mq: enforce op-specific segment limits in blk_insert_cloned_request X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jens Axboe , linux-block@vger.kernel.org, dm-devel@redhat.com, Mike Snitzer , Alasdair Kergon Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed, Feb 15, 2023 at 10:09:36PM -0800, Christoph Hellwig wrote: > I'd just remove the debug check entirely Older kernels have these checks in a separate function called blk_cloned_rq_check_limits, which carries the following comment: /** * blk_cloned_rq_check_limits - Helper function to check a cloned request * for the new queue limits * @q: the queue * @rq: the request being checked * * Description: * @rq may have been made based on weaker limitations of upper-level queues * in request stacking drivers, and it may violate the limitation of @q. * Since the block layer and the underlying device driver trust @rq * after it is inserted to @q, it should be checked against @q before * the insertion using this generic function. * * Request stacking drivers like request-based dm may change the queue * limits when retrying requests on other queues. Those requests need * to be checked against the new queue limits again during dispatch. */. Is this concern no longer relevant? -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C986C636CC for ; Thu, 16 Feb 2023 19:27:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229650AbjBPT1L (ORCPT ); Thu, 16 Feb 2023 14:27:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229475AbjBPT1K (ORCPT ); Thu, 16 Feb 2023 14:27:10 -0500 Received: from mail-pj1-x1064.google.com (mail-pj1-x1064.google.com [IPv6:2607:f8b0:4864:20::1064]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12D264DE04 for ; Thu, 16 Feb 2023 11:27:04 -0800 (PST) Received: by mail-pj1-x1064.google.com with SMTP id w20-20020a17090a8a1400b00233d7314c1cso6899395pjn.5 for ; Thu, 16 Feb 2023 11:27:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=ghxJBe9F/gi1ztZfAp08sB8NNLqrampvOT1lwb1dYDw=; b=RRnk5JV7NbvRDKiksh3LzOVGvGQf5jSLCUXimP0xasVFvQBbt+dYIPlwiYDALj62sR b7oJFU9wJ+aIwhKEoJbV7d368R2ybG1Ga+U3tk1V8EkhxhT7Otrl6DTe23NtIhIhUQd1 NzDwH2Dv7FkU+ckgJ1T8+pB7WXGh6TaKpEdooDcQeVbhn56B3jIvAitHd1WP/FyVRFe3 5hBqUq46vCEIqrHPd0w2IRW5fgdHaZYke8+FBZw4g3aGold5mk8O+WL6xVu5pjgNHIxx s3Rft6Aao4BpQ6Zp32AxraypZ0Xi54fzO9bfssbHnBW/TEZUje7PtOWuVvAx4Jsb0n2H oskA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=ghxJBe9F/gi1ztZfAp08sB8NNLqrampvOT1lwb1dYDw=; b=1ogL8Qou9LAOfqhX6fArH0mDLTo7YT+9EGVRWRiskNjb8xZmY79Pw7faG+ye1FNXGm adH7PiF1qlCEsm7jOymV4Ba8dN2gQUrZHg3Eqr+cP7x78LMGj9OIxQ8LbLSoJ1OJ9IcK 9rgOh1zPGSMN9TTVR3x9wtu7Gw0H0yzK8OUkTJukW1IN+3eQvDinHdeFapVGq70TMrk1 t6JuydKpQwkrtSA0Rs2rfYWlGaNcjJSCeymOjnAfTdZKTkJvWJio1kK2jJqM8TPa17j+ lphutSdDO1T4j8QBtxGjXVTwa3WIvZyYGmmlcz8hDUir555PVhRxDaqIcP428x5L1tUL 2HOw== X-Gm-Message-State: AO0yUKX/fc1FtndC6P1CSeQQzvDZ7fWFkyDGUFBBYS6xW+K63QoZqr2h dUea2yaS7JnnguLPkZ8A6Q+FJsFmgUvKEEjHj5ixDReaiRfQTo834jsiyNDYsHIBRQ== X-Google-Smtp-Source: AK7set/tXZ+EgPepRguZedA3khzI9tJlpcxsA1zsmkTgODhTRA/fB376DbygzXK1LBiY2RLtW5OmcNuoVz5S X-Received: by 2002:a17:90b:1e49:b0:233:f7a5:9942 with SMTP id pi9-20020a17090b1e4900b00233f7a59942mr7965483pjb.30.1676575623337; Thu, 16 Feb 2023 11:27:03 -0800 (PST) Received: from c7-smtp.dev.purestorage.com ([2620:125:9007:320:7:32:106:0]) by smtp-relay.gmail.com with ESMTPS id l4-20020a17090aaa8400b0023413f68b7esm123360pjq.7.2023.02.16.11.27.03 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Feb 2023 11:27:03 -0800 (PST) X-Relaying-Domain: purestorage.com Received: from dev-ushankar.dev.purestorage.com (dev-ushankar.dev.purestorage.com [10.7.70.36]) by c7-smtp.dev.purestorage.com (Postfix) with ESMTP id 7857C220FA; Thu, 16 Feb 2023 12:27:02 -0700 (MST) Received: by dev-ushankar.dev.purestorage.com (Postfix, from userid 1557716368) id 734D2E4068D; Thu, 16 Feb 2023 12:27:02 -0700 (MST) Date: Thu, 16 Feb 2023 12:27:02 -0700 From: Uday Shankar To: Christoph Hellwig Cc: Jens Axboe , Alasdair Kergon , Mike Snitzer , linux-block@vger.kernel.org, dm-devel@redhat.com Subject: Re: [PATCH] blk-mq: enforce op-specific segment limits in blk_insert_cloned_request Message-ID: <20230216192702.GA801590@dev-ushankar.dev.purestorage.com> References: <20230215201507.494152-1-ushankar@purestorage.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Feb 15, 2023 at 10:09:36PM -0800, Christoph Hellwig wrote: > I'd just remove the debug check entirely Older kernels have these checks in a separate function called blk_cloned_rq_check_limits, which carries the following comment: /** * blk_cloned_rq_check_limits - Helper function to check a cloned request * for the new queue limits * @q: the queue * @rq: the request being checked * * Description: * @rq may have been made based on weaker limitations of upper-level queues * in request stacking drivers, and it may violate the limitation of @q. * Since the block layer and the underlying device driver trust @rq * after it is inserted to @q, it should be checked against @q before * the insertion using this generic function. * * Request stacking drivers like request-based dm may change the queue * limits when retrying requests on other queues. Those requests need * to be checked against the new queue limits again during dispatch. */. Is this concern no longer relevant?