From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752767AbbBQBxW (ORCPT ); Mon, 16 Feb 2015 20:53:22 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33667 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751587AbbBQBvL (ORCPT ); Mon, 16 Feb 2015 20:51:11 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jakob Bornecrantz" , "Thomas Hellstrom" , "Sinclair Yeh" Date: Tue, 17 Feb 2015 01:46:53 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 048/152] drm/vmwgfx: Don't use memory accounting for kernel-side fence objects In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.67-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Hellstrom commit 1f563a6a46544602183e7493b6ef69769d3d76d9 upstream. Kernel side fence objects are used when unbinding resources and may thus be created as part of a memory reclaim operation. This might trigger recursive memory reclaims and result in the kernel running out of stack space. So a simple way out is to avoid accounting of these fence objects. In principle this is OK since while user-space can trigger the creation of such objects, it can't really hold on to them. However, their lifetime is quite long, so some form of accounting should perhaps be implemented in the future. Fixes kernel crashes when running, for example viewperf11 ensight-04 test 3 with low system memory settings. Signed-off-by: Thomas Hellstrom Reviewed-by: Jakob Bornecrantz Reviewed-by: Sinclair Yeh [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c @@ -484,14 +484,7 @@ void vmw_fence_obj_flush(struct vmw_fenc static void vmw_fence_destroy(struct vmw_fence_obj *fence) { - struct vmw_fence_manager *fman = fence->fman; - kfree(fence); - /* - * Free kernel space accounting. - */ - ttm_mem_global_free(vmw_mem_glob(fman->dev_priv), - fman->fence_size); } int vmw_fence_create(struct vmw_fence_manager *fman, @@ -499,20 +492,12 @@ int vmw_fence_create(struct vmw_fence_ma uint32_t mask, struct vmw_fence_obj **p_fence) { - struct ttm_mem_global *mem_glob = vmw_mem_glob(fman->dev_priv); struct vmw_fence_obj *fence; int ret; - ret = ttm_mem_global_alloc(mem_glob, fman->fence_size, - false, false); - if (unlikely(ret != 0)) - return ret; - fence = kzalloc(sizeof(*fence), GFP_KERNEL); - if (unlikely(fence == NULL)) { - ret = -ENOMEM; - goto out_no_object; - } + if (unlikely(fence == NULL)) + return -ENOMEM; ret = vmw_fence_obj_init(fman, fence, seqno, mask, vmw_fence_destroy); @@ -524,8 +509,6 @@ int vmw_fence_create(struct vmw_fence_ma out_err_init: kfree(fence); -out_no_object: - ttm_mem_global_free(mem_glob, fman->fence_size); return ret; }