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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 621E7CD1280 for ; Tue, 26 Mar 2024 12:06:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8938E10E915; Tue, 26 Mar 2024 12:06:21 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="OEj5cTLQ"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7C03610E36E; Tue, 26 Mar 2024 12:06:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1711454779; x=1742990779; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=VMOQQWQ8zlA4KMRdap0GxAhv5vGKeo6xRzJmQ3DuzK4=; b=OEj5cTLQptpqtSoWiY+ht8s2R+4CdeLMBv7/7o+yxlsF35pR9IVDxg+Q AxOuiLjqXMqtgiWNVWXKTq67XPTFY/3JdMfcWL8WSlj6aV9ExvHEkI/ry s0QgYIJi/KYhui/6p+I/b2ujsPWg0GixDwbIQIZwLwC8Tevwdkcf+FD0e KwMnITD7ljBUlzkXXItvDmDa8BTLteopJzfrkh2EKmN3V54NnGer2h22d AZmAgch8y0CHyY2ptG9s97wYFYOrqCaj1zpT1U2L58lIG7QnVPD/kCNAQ QTQQfCy+eCHrodDArEqZtMoQs+MeLJOmDH6s9OOZGmIQKUwZ8gjmbxDkt g==; X-CSE-ConnectionGUID: qKm1MrcGRmukf9VrL1958w== X-CSE-MsgGUID: wNBV4AUTQNmDFedrOoC+nQ== X-IronPort-AV: E=McAfee;i="6600,9927,11024"; a="17229270" X-IronPort-AV: E=Sophos;i="6.07,156,1708416000"; d="scan'208";a="17229270" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Mar 2024 05:05:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,156,1708416000"; d="scan'208";a="15928553" Received: from nirmoyda-mobl.ger.corp.intel.com (HELO [10.246.52.33]) ([10.246.52.33]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Mar 2024 05:05:39 -0700 Message-ID: <49e4ab49-e928-475a-bbaf-19c9009fdd1f@linux.intel.com> Date: Tue, 26 Mar 2024 13:05:37 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/i915/gem: Calculate object page offset for partial memory mapping To: Andi Shyti Cc: intel-gfx , dri-devel , Andi Shyti , Chris Wilson , Lionel Landwerlin References: <20240325134033.287913-1-andi.shyti@linux.intel.com> Content-Language: en-US From: Nirmoy Das In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Hi Andi, On 3/26/2024 12:12 PM, Andi Shyti wrote: > Hi Nirmoy, > > ... > >>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c >>> index a2195e28b625..57a2dda2c3cc 100644 >>> --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c >>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c >>> @@ -276,7 +276,7 @@ static vm_fault_t vm_fault_cpu(struct vm_fault *vmf) >>> /* PTEs are revoked in obj->ops->put_pages() */ >>> err = remap_io_sg(area, >>> area->vm_start, area->vm_end - area->vm_start, >>> - obj->mm.pages->sgl, iomap); >>> + obj->mm.pages->sgl, 0, iomap); >> Why don't we need partial mmap for CPU but only for GTT ? > As far as I understood we don't. I have a version with the CPU > offset as well in trybot[*] > > But without support for segmented buffer objects, I don't know > how much this has any effect. You confused me more :) Why segmented buffer object is needed for partial CPU mmap but not for GTT  ? From high level,  GTT and CPU both should support partial mmap unless I missing something here. > >> Sounds like this also need to be cover by a IGT tests. > Yes, I it does need some igt work, working on it. > >> Don't we need "Fixes" tag for this? > Why should we? I'm not fixing anything here, If userspace  expects partial mmap to work then this is a bug/gap in i915 so we need to backport this as far as possible. Need some information about the requirement about  why we need this patch suddenly? Regards, Nirmoy > I'm just > recalculating the mapping not starting from the beginning of the > scatter page. > > Andi > > [*] https://patchwork.freedesktop.org/patch/584474/?series=131539&rev=2