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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 94259C3A5A4 for ; Fri, 30 Aug 2019 11:16:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71E7621897 for ; Fri, 30 Aug 2019 11:16:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727753AbfH3LQH (ORCPT ); Fri, 30 Aug 2019 07:16:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35064 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726969AbfH3LQG (ORCPT ); Fri, 30 Aug 2019 07:16:06 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5A3353CA0C; Fri, 30 Aug 2019 11:16:06 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-95.ams2.redhat.com [10.36.116.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id DA4755C207; Fri, 30 Aug 2019 11:16:05 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 1CE2217536; Fri, 30 Aug 2019 13:16:05 +0200 (CEST) Date: Fri, 30 Aug 2019 13:16:05 +0200 From: Gerd Hoffmann To: David Riley Cc: dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org, David Airlie , Daniel Vetter , Gurchetan Singh , =?utf-8?B?U3TDqXBoYW5l?= Marchesin , linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/virtio: Use vmalloc for command buffer allocations. Message-ID: <20190830111605.twzssycagmjhfa45@sirius.home.kraxel.org> References: <20190829212417.257397-1-davidriley@chromium.org> <20190830060857.tzrzgoi2hrmchdi5@sirius.home.kraxel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 30 Aug 2019 11:16:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, > > > - kfree(vbuf->data_buf); > > > + kvfree(vbuf->data_buf); > > > > if (is_vmalloc_addr(vbuf->data_buf)) ... > > > > needed here I gues? > > > > kvfree() handles vmalloc/kmalloc/kvmalloc internally by doing that check. Ok. > - videobuf_vmalloc_to_sg in drivers/media/v4l2-core/videobuf-dma-sg.c, > assumes contiguous array of scatterlist and that the buffer being converted > is page aligned Well, vmalloc memory _is_ page aligned. sg_alloc_table_from_pages() does alot of what you need, you just need a small loop around vmalloc_to_page() create a struct page array beforehand. Completely different approach: use get_user_pages() and don't copy the execbuffer at all. cheers, Gerd