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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 2DEC8C2D0E2 for ; Tue, 22 Sep 2020 08:24:25 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A7CA6239E5 for ; Tue, 22 Sep 2020 08:24:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7CA6239E5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BE9AC6E05F; Tue, 22 Sep 2020 08:24:23 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9378B6E072; Tue, 22 Sep 2020 08:24:08 +0000 (UTC) IronPort-SDR: Glbrks/XNEQSc8Xa+PyEAtJDg8/l1R4qZ32Wn25QHKnosXE8o4PzbDRqbEZNYjnEzosciu6ogX IMBnqWSkjGTA== X-IronPort-AV: E=McAfee;i="6000,8403,9751"; a="157936728" X-IronPort-AV: E=Sophos;i="5.77,290,1596524400"; d="scan'208";a="157936728" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2020 01:24:08 -0700 IronPort-SDR: hYPYeshgQ9gLbxA+nGdC2UUT7a+sUMfvmmOdnILx1oZilih/OM+HLuWniJZ+KnDxCiUxxvah+K LMJGx+/weQGQ== X-IronPort-AV: E=Sophos;i="5.77,290,1596524400"; d="scan'208";a="454404248" Received: from atroib-mobl2.ger.corp.intel.com (HELO [10.214.238.184]) ([10.214.238.184]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2020 01:24:02 -0700 To: Christoph Hellwig , Matthew Wilcox References: <20200918163724.2511-1-hch@lst.de> <20200918163724.2511-4-hch@lst.de> <20200921191157.GX32101@casper.infradead.org> <20200922062249.GA30831@lst.de> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <43d10588-2033-038b-14e4-9f41cd622d7b@linux.intel.com> Date: Tue, 22 Sep 2020 09:23:59 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200922062249.GA30831@lst.de> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH 3/6] drm/i915: use vmap in shmem_pin_map X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Stefano Stabellini , Minchan Kim , Peter Zijlstra , intel-gfx@lists.freedesktop.org, x86@kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Chris Wilson , linux-mm@kvack.org, Matthew Auld , xen-devel@lists.xenproject.org, Boris Ostrovsky , Andrew Morton , Nitin Gupta Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 22/09/2020 07:22, Christoph Hellwig wrote: > On Mon, Sep 21, 2020 at 08:11:57PM +0100, Matthew Wilcox wrote: >> This is awkward. I'd like it if we had a vfree() variant which called >> put_page() instead of __free_pages(). I'd like it even more if we >> used release_pages() instead of our own loop that called put_page(). > > Note that we don't need a new vfree variant, we can do this manually if > we want, take a look at kernel/dma/remap.c. But I thought this code > intentionally doesn't want to do that to avoid locking in the memory > for the pages array. Maybe the i915 maintainers can clarify. + Chris & Matt who were involved with this part of i915. If I understood this sub-thread correctly, iterating and freeing the pages via the vmapped ptes, so no need for a shmem_read_mapping_page_gfp loop in shmem_unpin_map looks plausible to me. I did not get the reference to kernel/dma/remap.c though, and also not sure how to do the error unwind path in shmem_pin_map at which point the allocated vm area hasn't been fully populated yet. Hand-roll the loop walking vm area struct in there? Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx