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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 E5F1BC433DB for ; Tue, 30 Mar 2021 10:21:35 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 43D9061955 for ; Tue, 30 Mar 2021 10:21:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43D9061955 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id E05184018E; Tue, 30 Mar 2021 10:21:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zpu65_y6tf1T; Tue, 30 Mar 2021 10:21:34 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp2.osuosl.org (Postfix) with ESMTP id C29F3400D3; Tue, 30 Mar 2021 10:21:33 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 98CFFC000B; Tue, 30 Mar 2021 10:21:33 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 61EFBC000A for ; Tue, 30 Mar 2021 10:21:32 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 43247400FC for ; Tue, 30 Mar 2021 10:21:32 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4EygRpceYIba for ; Tue, 30 Mar 2021 10:21:31 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp2.osuosl.org (Postfix) with ESMTP id 67392400D3 for ; Tue, 30 Mar 2021 10:21:31 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 737E5ED1; Tue, 30 Mar 2021 03:21:30 -0700 (PDT) Received: from [10.57.27.121] (unknown [10.57.27.121]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B79213F792; Tue, 30 Mar 2021 03:21:29 -0700 (PDT) Subject: Re: [PATCH] dma-mapping: add unlikely hint to error path in dma_mapping_error To: Heiner Kallweit , Christoph Hellwig , Marek Szyprowski References: <78757abc-ef8f-9a29-9020-967370eec365@gmail.com> From: Robin Murphy Message-ID: Date: Tue, 30 Mar 2021 11:21:25 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <78757abc-ef8f-9a29-9020-967370eec365@gmail.com> Content-Language: en-GB Cc: "open list:AMD IOMMU \(AMD-VI\)" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 2021-03-26 21:03, Heiner Kallweit wrote: > Zillions of drivers use the unlikely() hint when checking the result of > dma_mapping_error(). This is an inline function anyway, so we can move > the hint into the function and remove it from drivers over time. I'm pretty sure I reviewed this last time - please remember to pick up tags from previous versions when reposting. Thanks, Robin. > Signed-off-by: Heiner Kallweit > --- > This is a resend of a patch from Dec 2020 when I tried to do it > tree-wide. Now start with the actual change, drivers can be changed > afterwards, maybe per subsystem. > --- > include/linux/dma-mapping.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index e9d19b974..183e7103a 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -95,7 +95,7 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) > { > debug_dma_mapping_error(dev, dma_addr); > > - if (dma_addr == DMA_MAPPING_ERROR) > + if (unlikely(dma_addr == DMA_MAPPING_ERROR)) > return -ENOMEM; > return 0; > } > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu