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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 C4170C63697 for ; Sun, 15 Nov 2020 00:11:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9254824179 for ; Sun, 15 Nov 2020 00:11:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726412AbgKOALS convert rfc822-to-8bit (ORCPT ); Sat, 14 Nov 2020 19:11:18 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:2434 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726125AbgKOALS (ORCPT ); Sat, 14 Nov 2020 19:11:18 -0500 Received: from dggeme758-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4CYXfw0Rmtz52lf; Sun, 15 Nov 2020 08:11:04 +0800 (CST) Received: from dggemi761-chm.china.huawei.com (10.1.198.147) by dggeme758-chm.china.huawei.com (10.3.19.104) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Sun, 15 Nov 2020 08:11:15 +0800 Received: from dggemi761-chm.china.huawei.com ([10.9.49.202]) by dggemi761-chm.china.huawei.com ([10.9.49.202]) with mapi id 15.01.1913.007; Sun, 15 Nov 2020 08:11:15 +0800 From: "Song Bao Hua (Barry Song)" To: Christoph Hellwig CC: "iommu@lists.linux-foundation.org" , "robin.murphy@arm.com" , "m.szyprowski@samsung.com" , Linuxarm , "linux-kselftest@vger.kernel.org" , "xuwei (O)" , Joerg Roedel , Will Deacon , Shuah Khan Subject: RE: [PATCH v3 1/2] dma-mapping: add benchmark support for streaming DMA APIs Thread-Topic: [PATCH v3 1/2] dma-mapping: add benchmark support for streaming DMA APIs Thread-Index: AQHWuqaxiT3rvc8AvUKektYgWKvLn6nIS8nQ Date: Sun, 15 Nov 2020 00:11:15 +0000 Message-ID: <5c4488dd28fc4869b7e67dd842ffa208@hisilicon.com> References: <20201102080646.2180-1-song.bao.hua@hisilicon.com> <20201102080646.2180-2-song.bao.hua@hisilicon.com> <20201114165336.GA24844@lst.de> In-Reply-To: <20201114165336.GA24844@lst.de> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.126.202.148] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org > -----Original Message----- > From: Christoph Hellwig [mailto:hch@lst.de] > Sent: Sunday, November 15, 2020 5:54 AM > To: Song Bao Hua (Barry Song) > Cc: iommu@lists.linux-foundation.org; hch@lst.de; robin.murphy@arm.com; > m.szyprowski@samsung.com; Linuxarm ; > linux-kselftest@vger.kernel.org; xuwei (O) ; Joerg > Roedel ; Will Deacon ; Shuah Khan > > Subject: Re: [PATCH v3 1/2] dma-mapping: add benchmark support for > streaming DMA APIs > > Lots of > 80 char lines. Please fix up the style. Checkpatch has changed 80 to 100. That's probably why my local checkpatch didn't report any warning: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bdc48fa11e46f867ea4d I am happy to change them to be less than 80 if you like. > > I think this needs to set a dma mask as behavior for unlimited dma > mask vs the default 32-bit one can be very different. I actually prefer users bind real devices with real dma_mask to test rather than force to change the dma_mask in this benchmark. Some device might have 32bit dma_mask while some others might have unlimited. But both of them can bind to this driver or unbind from it after the test is done. So users just need to bind those different real devices with different real dma_mask to dma_benchmark. This can reflect the real performance of the real device better, I think. > I also think you need to be able to pass the direction or have different tests > for directions. bidirectional is not exactly heavily used and pays > more cache management penality. For this, I'd like to increase a direction option in the test app and pass the option to the benchmark driver. Thanks Barry