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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 47ABDC433EF for ; Thu, 28 Apr 2022 14:55:57 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id CF58E41B81; Thu, 28 Apr 2022 14:55:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id oRZXPuPSi_ri; Thu, 28 Apr 2022 14:55:55 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTPS id 4036041B7E; Thu, 28 Apr 2022 14:55:55 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 14A0CC0032; Thu, 28 Apr 2022 14:55:55 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 39176C0032 for ; Thu, 28 Apr 2022 14:55:53 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id C570860B69 for ; Thu, 28 Apr 2022 14:55:48 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp3.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=intel.com Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RYWBOjy76iWm for ; Thu, 28 Apr 2022 14:55:48 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by smtp3.osuosl.org (Postfix) with ESMTPS id BA8D960F96 for ; Thu, 28 Apr 2022 14:55:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651157747; x=1682693747; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=TymbHLQLOivBB5TuFgZIkk0oRKZgOsSXpf3tD9EpOrU=; b=IjBbgL6GAxmiLubWRHk2F8rwricNGp88WZpAvSyhtpANnykRjIVtWq5l yColHW9LG02A1oRL7Lv3XYm4NTJx8pm30LK7V6Tcwr6Woatu2lbzbDBy5 T4VUWUDIOONTpnKnZ5o+BXDAJP/B4agVX3dZVU/n6DsBc7fAtOB8k9Okc vqH6WNM3N32mA+N8bzwt00CnuEw6BMpJ0QuwmQIqRz2w2d81hfc15a9+F IugPdfySxkh4iArr5hdwsqmuJsBp/wJKL4mkJHKB58bSbRSCU0QyxzRG2 apSzSd8iHer4QebELHpuYl72NRp4Yw7axk9eJndkloylZm6Fq6pEGa9cB w==; X-IronPort-AV: E=McAfee;i="6400,9594,10330"; a="329257698" X-IronPort-AV: E=Sophos;i="5.91,295,1647327600"; d="scan'208";a="329257698" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2022 07:55:46 -0700 X-IronPort-AV: E=Sophos;i="5.91,295,1647327600"; d="scan'208";a="651252042" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.19.92]) ([10.209.19.92]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2022 07:55:44 -0700 Message-ID: <1517d2f0-08d6-a532-7810-2161b2dff421@linux.intel.com> Date: Thu, 28 Apr 2022 07:55:39 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [RFC PATCH 1/2] swiotlb: Split up single swiotlb lock Content-Language: en-US To: Christoph Hellwig , Robin Murphy References: <20220428141429.1637028-1-ltykernel@gmail.com> <20220428141429.1637028-2-ltykernel@gmail.com> From: Andi Kleen In-Reply-To: Cc: parri.andrea@gmail.com, thomas.lendacky@amd.com, wei.liu@kernel.org, Tianyu Lan , konrad.wilk@oracle.com, linux-hyperv@vger.kernel.org, Tianyu Lan , linux-kernel@vger.kernel.org, michael.h.kelley@microsoft.com, iommu@lists.linux-foundation.org, andi.kleen@intel.com, brijesh.singh@amd.com, vkuznets@redhat.com, kys@microsoft.com, kirill.shutemov@intel.com, hch@lst.de 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 4/28/2022 7:45 AM, Christoph Hellwig wrote: > On Thu, Apr 28, 2022 at 03:44:36PM +0100, Robin Murphy wrote: >> Rather than introduce this extra level of allocator complexity, how about >> just dividing up the initial SWIOTLB allocation into multiple io_tlb_mem >> instances? > Yeah. We're almost done removing all knowledge of swiotlb from drivers, > so the very last thing I want is an interface that allows a driver to > allocate a per-device buffer. At least for TDX need parallelism with a single device for performance. So if you split up the io tlb mems for a device then you would need a new mechanism to load balance the requests for single device over those. I doubt it would be any simpler. -Andi _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu