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 59DBCC433F5 for ; Tue, 7 Dec 2021 10:06:43 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C105A73894; Tue, 7 Dec 2021 10:06:42 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id CE55973894; Tue, 7 Dec 2021 10:06:41 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10190"; a="261610367" X-IronPort-AV: E=Sophos;i="5.87,293,1631602800"; d="scan'208";a="261610367" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2021 02:06:41 -0800 X-IronPort-AV: E=Sophos;i="5.87,293,1631602800"; d="scan'208";a="515213213" Received: from rbogdano-mobl.ger.corp.intel.com (HELO [10.252.51.186]) ([10.252.51.186]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2021 02:06:39 -0800 Message-ID: Date: Tue, 7 Dec 2021 11:06:36 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.3.2 Content-Language: en-US To: Matthew Auld References: <20211129134735.628712-1-maarten.lankhorst@linux.intel.com> <20211129134735.628712-4-maarten.lankhorst@linux.intel.com> From: Maarten Lankhorst In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Intel-gfx] [PATCH v2 03/16] drm/i915: Remove pages_mutex and intel_gtt->vma_ops.set/clear_pages members, v2. 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: Intel Graphics Development , ML dri-devel Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 06-12-2021 18:10, Matthew Auld wrote: > On Mon, 29 Nov 2021 at 13:57, Maarten Lankhorst > wrote: >> Big delta, but boils down to moving set_pages to i915_vma.c, and removing >> the special handling, all callers use the defaults anyway. We only remap >> in ggtt, so default case will fall through. >> >> Because we still don't require locking in i915_vma_unpin(), handle this by >> using xchg in get_pages(), as it's locked with obj->mutex, and cmpxchg in >> unpin, which only fails if we race a against a new pin. >> >> Changes since v1: >> - aliasing gtt sets ZERO_SIZE_PTR, not -ENODEV, remove special case >> from __i915_vma_get_pages(). (Matt) >> >> Signed-off-by: Maarten Lankhorst > > >> +static int >> +__i915_vma_get_pages(struct i915_vma *vma) >> +{ >> + struct sg_table *pages; >> + int ret; >> + >> + /* >> + * The vma->pages are only valid within the lifespan of the borrowed >> + * obj->mm.pages. When the obj->mm.pages sg_table is regenerated, so >> + * must be the vma->pages. A simple rule is that vma->pages must only >> + * be accessed when the obj->mm.pages are pinned. >> + */ >> + GEM_BUG_ON(!i915_gem_object_has_pinned_pages(vma->obj)); >> + >> + switch (vma->ggtt_view.type) { >> + default: >> + GEM_BUG_ON(vma->ggtt_view.type); >> + fallthrough; >> + case I915_GGTT_VIEW_NORMAL: >> + pages = vma->obj->mm.pages; >> + break; >> + >> + case I915_GGTT_VIEW_ROTATED: >> + pages = >> + intel_rotate_pages(&vma->ggtt_view.rotated, vma->obj); >> + break; >> + >> + case I915_GGTT_VIEW_REMAPPED: >> + pages = >> + intel_remap_pages(&vma->ggtt_view.remapped, vma->obj); >> + break; >> + >> + case I915_GGTT_VIEW_PARTIAL: >> + pages = intel_partial_pages(&vma->ggtt_view, vma->obj); >> + break; >> + } >> + >> + ret = 0; >> + if (IS_ERR(pages)) { >> + ret = PTR_ERR(pages); >> + pages = NULL; >> + drm_err(&vma->vm->i915->drm, >> + "Failed to get pages for VMA view type %u (%d)!\n", >> + vma->ggtt_view.type, ret); >> + } >> + >> + pages = xchg(&vma->pages, pages); >> + >> + /* did we race against a put_pages? */ >> + if (pages && pages != vma->obj->mm.pages) { >> + sg_free_table(vma->pages); >> + kfree(vma->pages); > So should this one rather be: > > sg_free_table(pages); > kfree(pages); > > Or am I missing something? Correct! I missed it. Will fix it up when committing, or if a new version is needed.