From patchwork Mon Jan 4 10:11:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 7946521 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D6B18BEEE5 for ; Mon, 4 Jan 2016 10:11:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EA89F2037F for ; Mon, 4 Jan 2016 10:11:17 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id E26A220306 for ; Mon, 4 Jan 2016 10:11:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 55AEB6E099; Mon, 4 Jan 2016 02:11:16 -0800 (PST) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [87.106.93.118]) by gabe.freedesktop.org (Postfix) with ESMTP id 6C2086E094; Mon, 4 Jan 2016 02:11:14 -0800 (PST) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 50796526-1500048 for multiple; Mon, 04 Jan 2016 10:12:07 +0000 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Mon, 04 Jan 2016 10:11:08 +0000 From: Chris Wilson To: dri-devel@lists.freedesktop.org Date: Mon, 4 Jan 2016 10:11:00 +0000 Message-Id: <1451902261-25380-2-git-send-email-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1451902261-25380-1-git-send-email-chris@chris-wilson.co.uk> References: <1451902261-25380-1-git-send-email-chris@chris-wilson.co.uk> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Cc: intel-gfx@lists.freedesktop.org Subject: [Intel-gfx] [PATCH 2/3] drm: Only bump object-reference count when adding first handle X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We only need a single reference count for all handles (i.e. non-zero obj->handle_count) and so can trim a few atomic operations by only taking the reference on the first handle and dropping it after the last. Signed-off-by: Chris Wilson Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/drm_gem.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index a08176debc0e..ad955d7c99fd 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -220,6 +220,9 @@ static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) static void drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) { + struct drm_device *dev = obj->dev; + bool final = false; + if (WARN_ON(obj->handle_count == 0)) return; @@ -229,14 +232,16 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) * checked for a name */ - mutex_lock(&obj->dev->object_name_lock); + mutex_lock(&dev->object_name_lock); if (--obj->handle_count == 0) { drm_gem_object_handle_free(obj); drm_gem_object_exported_dma_buf_free(obj); + final = true; } - mutex_unlock(&obj->dev->object_name_lock); + mutex_unlock(&dev->object_name_lock); - drm_gem_object_unreference_unlocked(obj); + if (final) + drm_gem_object_unreference_unlocked(obj); } /** @@ -329,6 +334,8 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, int ret; WARN_ON(!mutex_is_locked(&dev->object_name_lock)); + if (obj->handle_count++ == 0) + drm_gem_object_reference(obj); /* * Get the user-visible handle using idr. Preload and perform @@ -338,10 +345,10 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, spin_lock(&file_priv->table_lock); ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); - drm_gem_object_reference(obj); - obj->handle_count++; + spin_unlock(&file_priv->table_lock); idr_preload_end(); + mutex_unlock(&dev->object_name_lock); if (ret < 0) goto err_unref;