From patchwork Fri May 25 09:31:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10426711 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D172D6032C for ; Fri, 25 May 2018 09:32:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BE0EB29615 for ; Fri, 25 May 2018 09:32:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B31EC29616; Fri, 25 May 2018 09:32:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AE7A52961A for ; Fri, 25 May 2018 09:32:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9334B6E8ED; Fri, 25 May 2018 09:32:20 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id B5A6A6E178 for ; Fri, 25 May 2018 09:32:19 +0000 (UTC) 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 11837979-1500050 for multiple; Fri, 25 May 2018 10:32:12 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Fri, 25 May 2018 10:32:11 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 25 May 2018 10:31:50 +0100 Message-Id: <20180525093206.1919-3-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180525093206.1919-1-chris@chris-wilson.co.uk> References: <20180525093206.1919-1-chris@chris-wilson.co.uk> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 02/18] drm/i915: Switch to kernel context before idling at runtime X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 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-Virus-Scanned: ClamAV using ClamSMTP We can reduce our exposure to random neutrinos by resting on the kernel context having flushed out the user contexts to system memory and beyond. The corollary is that we then we require two passes through the idle handler to go to sleep, which on a truly idle system involves an extra pass through the slow and irregular retire work handler. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_debugfs.c | 7 +++++-- drivers/gpu/drm/i915/i915_gem.c | 29 ++++++++++++++++++++++++----- 2 files changed, 29 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index a8e7761cdc7d..0fb86a8ef192 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4226,8 +4226,11 @@ i915_drop_caches_set(void *data, u64 val) i915_gem_shrink_all(dev_priv); fs_reclaim_release(GFP_KERNEL); - if (val & DROP_IDLE) - drain_delayed_work(&dev_priv->gt.idle_work); + if (val & DROP_IDLE) { + do { + drain_delayed_work(&dev_priv->gt.idle_work); + } while (READ_ONCE(dev_priv->gt.awake)); + } if (val & DROP_FREED) i915_gem_drain_freed_objects(dev_priv); diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 05f44ca35a06..c93f5dcb1d82 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -139,6 +139,8 @@ int i915_mutex_lock_interruptible(struct drm_device *dev) static u32 __i915_gem_park(struct drm_i915_private *i915) { + GEM_TRACE("\n"); + lockdep_assert_held(&i915->drm.struct_mutex); GEM_BUG_ON(i915->gt.active_requests); GEM_BUG_ON(!list_empty(&i915->gt.active_rings)); @@ -193,6 +195,8 @@ void i915_gem_park(struct drm_i915_private *i915) void i915_gem_unpark(struct drm_i915_private *i915) { + GEM_TRACE("\n"); + lockdep_assert_held(&i915->drm.struct_mutex); GEM_BUG_ON(!i915->gt.active_requests); @@ -3504,6 +3508,21 @@ i915_gem_idle_work_handler(struct work_struct *work) if (!READ_ONCE(dev_priv->gt.awake)) return; + /* + * Flush out the last user context, leaving only the pinned + * kernel context resident. When we are idling on the kernel_context, + * no more new requests (with a context switch) are emitted and we + * can finally rest. A consequence is that the idle work handler is + * always called at least twice before idling (and if the system is + * idle that implies a round trip through the retire worker). + */ + mutex_lock(&dev_priv->drm.struct_mutex); + i915_gem_switch_to_kernel_context(dev_priv); + mutex_unlock(&dev_priv->drm.struct_mutex); + + GEM_TRACE("active_requests=%d (after switch-to-kernel-context)\n", + READ_ONCE(dev_priv->gt.active_requests)); + /* * Wait for last execlists context complete, but bail out in case a * new request is submitted. As we don't trust the hardware, we @@ -4914,11 +4933,9 @@ static void assert_kernel_context_is_current(struct drm_i915_private *i915) void i915_gem_sanitize(struct drm_i915_private *i915) { - if (i915_terminally_wedged(&i915->gpu_error)) { - mutex_lock(&i915->drm.struct_mutex); + mutex_lock(&i915->drm.struct_mutex); + if (i915_terminally_wedged(&i915->gpu_error)) i915_gem_unset_wedged(i915); - mutex_unlock(&i915->drm.struct_mutex); - } /* * If we inherit context state from the BIOS or earlier occupants @@ -4930,6 +4947,9 @@ void i915_gem_sanitize(struct drm_i915_private *i915) */ if (INTEL_GEN(i915) >= 5 && intel_has_gpu_reset(i915)) WARN_ON(intel_gpu_reset(i915, ALL_ENGINES)); + + i915_gem_contexts_lost(i915); + mutex_unlock(&i915->drm.struct_mutex); } int i915_gem_suspend(struct drm_i915_private *dev_priv) @@ -4965,7 +4985,6 @@ int i915_gem_suspend(struct drm_i915_private *dev_priv) assert_kernel_context_is_current(dev_priv); } - i915_gem_contexts_lost(dev_priv); mutex_unlock(&dev->struct_mutex); intel_uc_suspend(dev_priv);