From patchwork Thu Jun 26 17:24:18 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Harrison X-Patchwork-Id: 4429141 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 [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3B128BEEAA for ; Thu, 26 Jun 2014 17:25:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6CF0020381 for ; Thu, 26 Jun 2014 17:25:53 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 658C820351 for ; Thu, 26 Jun 2014 17:25:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C3E4D6E27E; Thu, 26 Jun 2014 10:25:50 -0700 (PDT) X-Original-To: Intel-GFX@lists.freedesktop.org Delivered-To: Intel-GFX@lists.freedesktop.org Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id 6F1126E246 for ; Thu, 26 Jun 2014 10:25:42 -0700 (PDT) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 26 Jun 2014 10:25:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,554,1400050800"; d="scan'208";a="561434779" Received: from johnharr-linux.iwi.intel.com ([172.28.253.52]) by fmsmga002.fm.intel.com with ESMTP; 26 Jun 2014 10:25:27 -0700 From: John.C.Harrison@Intel.com To: Intel-GFX@lists.freedesktop.org Date: Thu, 26 Jun 2014 18:24:18 +0100 Message-Id: <1403803475-16337-28-git-send-email-John.C.Harrison@Intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1403803475-16337-1-git-send-email-John.C.Harrison@Intel.com> References: <1403803475-16337-1-git-send-email-John.C.Harrison@Intel.com> Organization: Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ Subject: [Intel-gfx] [RFC 27/44] drm/i915: Added scheduler support to page fault handler X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.15 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, T_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 From: John Harrison GPU page faults can now require scheduler operation in order to complete. For example, in order to free up sufficient memory to handle the fault the handler must wait for a batch buffer to complete that has not even been sent to the hardware yet. Thus EAGAIN no longer means a GPU hang, it can occur under normal operation. --- drivers/gpu/drm/i915/i915_gem.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 5ed5f66..aa1e0b2 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1622,10 +1622,16 @@ out: } case -EAGAIN: /* - * EAGAIN means the gpu is hung and we'll wait for the error - * handler to reset everything when re-faulting in + * EAGAIN can mean the gpu is hung and we'll have to wait for + * the error handler to reset everything when re-faulting in * i915_mutex_lock_interruptible. + * + * It can also indicate various other nonfatal errors for which + * the best response is to give other threads a chance to run, + * and then retry the failing operation in its entirety. */ + set_need_resched(); + /*FALLTHRU*/ case 0: case -ERESTARTSYS: case -EINTR: