From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from esa2.hgst.iphmx.com (esa2.hgst.iphmx.com [68.232.143.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73787ECC for ; Mon, 18 Jul 2022 10:49:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1658141351; x=1689677351; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=7rBMGEx1YSGdVB6fbYn5Y5KkPOqfQscgrLN9anE2Owo=; b=aDbbYy/6SQcs0mhOKIZkXKDXWynhzGsUuU9Iwj8gxhQrg2FSi8ezqkU+ z0Dhrt5n/voM/6O+IbggO6CvBtwKo1sAqUg3Ov1Pwo1HP69251wt38ZVt BX0pM1sdbiqzPOeKtBbIm0R6Xz2kYpCpLxk7K4gapvXd1eMWqTYbbzvoI 51RqMn0JHVVjF0pvPDIhwkR8xVT3VpvwfeWkZhZqD3dADQNVFqk1PCt2n g1/9hr6XYQRV9JQeiorbbWRQlWqkvSuaV5Bxd+Aog0lK8COaS3hd2Ljgu kwxsjHmobvMIPaHwaac053gUIwHqVr62BgmMHkbk8bmFq5O17JxIG4gdM w==; X-IronPort-AV: E=Sophos;i="5.92,280,1650902400"; d="scan'208";a="310361195" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 18 Jul 2022 18:48:01 +0800 IronPort-SDR: EAkcZx1ZL46aKn0nWgdMXlzTFj7P007yyCWem9iutwQmQBtL+5ChQPjAFw4954gbFzBMKqJVrh cNfLE98CRZzItvb7MqMqhgAlg0eE/3qELAg2uA1ze8qtFoiCrmd/rKkaTI8kTfU4qcdjQS4xsS xY3LBtR+59jIAoqxwV/jnCUsTzMsLZDOTRAPbEn+lRS6Sl7vmixzswnM9enIYbHo5YGax5iUkU q7u7RpUAnxAV8UOhRP9RdYrXZnxXTwVeIK8CNifFJYkaKJI5NeYD0jIQW0J+sMTdnVpoX3sPbb JoAxDPa7QJpzFYjjiWGpLeB6 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 18 Jul 2022 03:09:27 -0700 IronPort-SDR: VI92L1u0z8oFCyCIdOP2kX/cwWR/LxrAYz/mgJ9NpCnVWqArrGTO+m2id9QNa+IWUeBtPNpfrU yBQagh2DFZQJuQTt6ajd1dkvyckRUnAGgmHPMX6taeE7bXusOujWahUgxw0Gu+Vjm9n83tE8Zy u4u2uN7W2Is0w4lDx9OSFBCyXCxLCcoBMc0oVNHS7FwfGdNumxlgl82yRht045MaJY1CM17Ht9 0h/wpCPNBUIyeHpcs+rFXow6uMKrKdlFNniRfhGSI6FebtF07xvLr8ucg1PGcoV8TUgcjX7HvP wG0= WDCIronportException: Internal Received: from usg-ed-osssrv.wdc.com ([10.3.10.180]) by uls-op-cesaip02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 18 Jul 2022 03:48:02 -0700 Received: from usg-ed-osssrv.wdc.com (usg-ed-osssrv.wdc.com [127.0.0.1]) by usg-ed-osssrv.wdc.com (Postfix) with ESMTP id 4LmdwK1Kq8z1Rw4L for ; Mon, 18 Jul 2022 03:48:01 -0700 (PDT) Authentication-Results: usg-ed-osssrv.wdc.com (amavisd-new); dkim=pass reason="pass (just generated, assumed good)" header.d=opensource.wdc.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d= opensource.wdc.com; h=content-transfer-encoding:content-type :in-reply-to:organization:from:references:to:content-language :subject:user-agent:mime-version:date:message-id; s=dkim; t= 1658141280; x=1660733281; bh=7rBMGEx1YSGdVB6fbYn5Y5KkPOqfQscgrLN 9anE2Owo=; b=bjN5B1j0Rkc2vSnTaBg0I6yZlDKb3jC/Ey1Ow71t0OK/WvsEBS6 zcLef5xxzvKAk6dN3xoqmSaUtbHCa7GpME+/Gyjh24WSx+3oRTp/RTNJw0MQirr9 /HS1V4UnLFvDu+T4pFMk4KY+3/YbTd/C+0K+2mxZS9H9jBJuF+QtICaIVfDFwcoq Xf2U2c1D81NnxfOvu3UB2HOllG4nhOn6akT3u2/VfBdiWtKfjfBzx9y4PQm2k+Ek 0JsdZ2kx7xVyP3FIIgro3g3SbxmL5fcX2NKc1Qc5XkWcUaSyDtLMWWgD9RAD5Dqz CmPSh/wyz5ZJehHEEZge/Uqk7PRq0biCTqg== X-Virus-Scanned: amavisd-new at usg-ed-osssrv.wdc.com Received: from usg-ed-osssrv.wdc.com ([127.0.0.1]) by usg-ed-osssrv.wdc.com (usg-ed-osssrv.wdc.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id CotKiXahLB0Q for ; Mon, 18 Jul 2022 03:48:00 -0700 (PDT) Received: from [10.225.163.120] (unknown [10.225.163.120]) by usg-ed-osssrv.wdc.com (Postfix) with ESMTPSA id 4LmdwG3P48z1RtVk; Mon, 18 Jul 2022 03:47:58 -0700 (PDT) Message-ID: Date: Mon, 18 Jul 2022 19:47:57 +0900 Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v6 5/6] scsi: scsi_transport_sas: Cap shost opt_sectors according to DMA optimal limit Content-Language: en-US To: John Garry , joro@8bytes.org, will@kernel.org, jejb@linux.ibm.com, martin.petersen@oracle.com, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, iommu@lists.linux.dev, linux-scsi@vger.kernel.org, linuxarm@huawei.com References: <1657797329-98541-1-git-send-email-john.garry@huawei.com> <1657797329-98541-6-git-send-email-john.garry@huawei.com> From: Damien Le Moal Organization: Western Digital Research In-Reply-To: <1657797329-98541-6-git-send-email-john.garry@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/14/22 20:15, John Garry wrote: > Streaming DMA mappings may be considerably slower when mappings go through > an IOMMU and the total mapping length is somewhat long. This is because the > IOMMU IOVA code allocates and free an IOVA for each mapping, which may > affect performance. > > For performance reasons set the request queue max_sectors from > dma_opt_mapping_size(), which knows this mapping limit. > > Signed-off-by: John Garry > --- > drivers/scsi/scsi_transport_sas.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c > index 12bff64dade6..2f88c61216ee 100644 > --- a/drivers/scsi/scsi_transport_sas.c > +++ b/drivers/scsi/scsi_transport_sas.c > @@ -225,6 +225,7 @@ static int sas_host_setup(struct transport_container *tc, struct device *dev, > { > struct Scsi_Host *shost = dev_to_shost(dev); > struct sas_host_attrs *sas_host = to_sas_host_attrs(shost); > + struct device *dma_dev = shost->dma_dev; > > INIT_LIST_HEAD(&sas_host->rphy_list); > mutex_init(&sas_host->lock); > @@ -236,6 +237,11 @@ static int sas_host_setup(struct transport_container *tc, struct device *dev, > dev_printk(KERN_ERR, dev, "fail to a bsg device %d\n", > shost->host_no); > > + if (dma_dev->dma_mask) { > + shost->opt_sectors = min_t(unsigned int, shost->max_sectors, > + dma_opt_mapping_size(dma_dev) >> SECTOR_SHIFT); > + } > + > return 0; > } > Reviewed-by: Damien Le Moal -- Damien Le Moal Western Digital Research