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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A8B2C433F5 for ; Thu, 28 Apr 2022 14:46:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348554AbiD1OtN (ORCPT ); Thu, 28 Apr 2022 10:49:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348468AbiD1OtM (ORCPT ); Thu, 28 Apr 2022 10:49:12 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D715A3EBB1; Thu, 28 Apr 2022 07:45:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Wn2CCgiEQBYeS5u0DrULazlSPjTmY85xMbHqQ/sfE9k=; b=SPFFyEzI2KXFZuWKlVBFsE45Rd tuKS6j1yQzuaKTnrAlz1qA+bdRp0MdXf0O9s3Ql9mZRr8J3YkTrFsILNWA7YNBS/Nv/t39FCxCROR tXXuwYUmj54la6tjSJJdhQkY2r7Gyb/KBAGV7ijwKv21aZIwO7PwdGKFY+wmCYNTYddTDO91VNnvu uyiL19/jkOa7B0xJIGnk+6PtoDefVlKJhqSsZLwAYcQC+ad/PJQx0tHgkuBlMOz0/Ii/yZ5wOpjSg 42DqbKhrYwHu7YObyKFJqvKBSjSziz8cT/nRHQwIv7ct+vBMSXzxTJxhloyCAAkkD3LpGxlxYBKK9 OUWI2eLg==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nk5Ou-007WzS-Oc; Thu, 28 Apr 2022 14:45:48 +0000 Date: Thu, 28 Apr 2022 07:45:48 -0700 From: Christoph Hellwig To: Robin Murphy Cc: Tianyu Lan , hch@infradead.org, m.szyprowski@samsung.com, michael.h.kelley@microsoft.com, kys@microsoft.com, parri.andrea@gmail.com, thomas.lendacky@amd.com, wei.liu@kernel.org, Andi Kleen , Tianyu Lan , linux-hyperv@vger.kernel.org, konrad.wilk@oracle.com, linux-kernel@vger.kernel.org, kirill.shutemov@intel.com, iommu@lists.linux-foundation.org, andi.kleen@intel.com, brijesh.singh@amd.com, vkuznets@redhat.com, hch@lst.de Subject: Re: [RFC PATCH 1/2] swiotlb: Split up single swiotlb lock Message-ID: References: <20220428141429.1637028-1-ltykernel@gmail.com> <20220428141429.1637028-2-ltykernel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.