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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED autolearn=ham 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 54EDCC3279B for ; Tue, 10 Jul 2018 18:28:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1BF512083E for ; Tue, 10 Jul 2018 18:28:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="b5Htvjnt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BF512083E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387566AbeGJS2v (ORCPT ); Tue, 10 Jul 2018 14:28:51 -0400 Received: from mail-io0-f196.google.com ([209.85.223.196]:46761 "EHLO mail-io0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732920AbeGJS2u (ORCPT ); Tue, 10 Jul 2018 14:28:50 -0400 Received: by mail-io0-f196.google.com with SMTP id i18-v6so5533367ioj.13 for ; Tue, 10 Jul 2018 11:28:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=YCJcwzgHg6b2PtZeCSrpNDW98r4gxMxNyeAT1AE0FRo=; b=b5HtvjntOac2U2JwmL4Om7jNGr+TXjRRF+PqQD5alWq0SCjFaYcOXHdhaXOPKLQsUk Z8NbCsRrrgD2ssHv0oQRxQIkZdzv+EtSI0AESZCZUEZp2irlT/LS5QOR3MWmQptzb4io CtYRpMXIoTQadPqCV7fDMH9uSGS4hKKtYBq2fuwkfSBjLygrSmJRSGJ6+LYa+cI3t+3Q Mae+e3IQn507OApBDeOjk3FcEvuM2hliugCU3cLfqzuwQsqU1WLDLDjMNU+U4jUGCVv9 53PiU9sULT8CiOm46Z/4QwGAs45mjvdvxRIBj+QVUhKxKy4Fo2MSZKU3w/RBUjw1WdoM 5TVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YCJcwzgHg6b2PtZeCSrpNDW98r4gxMxNyeAT1AE0FRo=; b=D+TmjGaoia3ivNqYDzzxvob7WHZyYBVz1EkCjpRLL1u3SEiVQQvRvhlON4rT02gvS+ Leuzs1Wc6fvXIn1x6A02LyiDddY92SZnAepL7uTD4mObi3KIx+npVpzD+28AC7LRlsbm AUYapsjarAFV3ESdqo1SLGf6XfxaM5jE0txvqZw9DP5TmDigEwaIpe25IkKnGpGug09A +/qu+X8NlnDy1ue4CkW/Qsdz33+FLUArJCxaM0RJKRNouQyDr8wP8LvnrLabiq9GgyBZ /QkkSywjqX5hCuShOYTEjK784nWQp170A9N0L1KEMM/afPuHPY/K6/v/K+Nm0bEMOGM5 M8Qw== X-Gm-Message-State: AOUpUlEK6zo9AJ8qt/njuQO1qpuXpRUGqdYVtsRLVS4NCo2vxGwV7oBb GEe1voLWFgFbYOzkJdOkZbPyRpQaALQ= X-Google-Smtp-Source: AAOMgpfo98Opq0peapICQaW7xZGkNnMNB99/JS8NG4CuiyMz9kPRxpObanrA8orLibmGO4kkEl2R+w== X-Received: by 2002:a5e:dc41:: with SMTP id s1-v6mr6074000iop.200.1531247318820; Tue, 10 Jul 2018 11:28:38 -0700 (PDT) Received: from [192.168.1.212] (107.191.0.158.static.utbb.net. [107.191.0.158]) by smtp.gmail.com with ESMTPSA id n124-v6sm5040itg.7.2018.07.10.11.28.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 10 Jul 2018 11:28:25 -0700 (PDT) Subject: Re: [PATCH] block: iolatency: avoid 64-bit division To: Arnd Bergmann Cc: Tejun Heo , Josef Bacik , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20180710152146.2371336-1-arnd@arndb.de> From: Jens Axboe Message-ID: Date: Tue, 10 Jul 2018 12:28:09 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20180710152146.2371336-1-arnd@arndb.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/10/18 9:21 AM, Arnd Bergmann wrote: > On 32-bit architectures, dividing a 64-bit number needs to use the > do_div() function or something like it to avoid a link failure: > > block/blk-iolatency.o: In function `iolatency_prfill_limit': > blk-iolatency.c:(.text+0x8cc): undefined reference to `__aeabi_uldivmod' > > Using div_u64() gives us the best output and avoids the need for an > explicit cast. Applied, thanks Arnd. -- Jens Axboe