From patchwork Fri Aug 10 07:11:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10562295 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D24D515A6 for ; Fri, 10 Aug 2018 07:13:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BCD09286EB for ; Fri, 10 Aug 2018 07:13:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B06A72B771; Fri, 10 Aug 2018 07:13:41 +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 AD56D286EB for ; Fri, 10 Aug 2018 07:13:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EEDD46E8A4; Fri, 10 Aug 2018 07:13:38 +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 363BC6E898 for ; Fri, 10 Aug 2018 07:13:36 +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 12770305-1500050 for multiple; Fri, 10 Aug 2018 08:11:46 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 10 Aug 2018 08:11:32 +0100 Message-Id: <20180810071138.30138-2-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180810071138.30138-1-chris@chris-wilson.co.uk> References: <20180810071138.30138-1-chris@chris-wilson.co.uk> Subject: [Intel-gfx] [RFC 2/8] drm/i915: Track all held rpm wakerefs 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 Everytime we take a wakeref, record the stack trace of where it was taken; clearing the set if we ever drop back to no owners. For debugging a rpm leak, we can look at all the current wakerefs and check if they have a matching rpm_put. Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/Kconfig.debug | 13 ++ drivers/gpu/drm/i915/i915_drv.c | 8 +- drivers/gpu/drm/i915/i915_drv.h | 7 + drivers/gpu/drm/i915/intel_drv.h | 32 ++-- drivers/gpu/drm/i915/intel_runtime_pm.c | 217 +++++++++++++++++++++--- 5 files changed, 233 insertions(+), 44 deletions(-) diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug index 459f8f88a34c..ed572a454e01 100644 --- a/drivers/gpu/drm/i915/Kconfig.debug +++ b/drivers/gpu/drm/i915/Kconfig.debug @@ -39,6 +39,19 @@ config DRM_I915_DEBUG If in doubt, say "N". +config DRM_I915_DEBUG_RPM + bool "Insert extra checks into the runtime pm internals" + depends on DRM_I915 + default n + select STACKDEPOT + help + Enable extra sanity checks (including BUGs) along the runtime pm + paths that may slow the system down and if hit hang the machine. + + Recommended for driver developers only. + + If in doubt, say "N". + config DRM_I915_DEBUG_GEM bool "Insert extra checks into the GEM internals" default n diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 62ef105a241d..b6e83043ac9d 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -908,6 +908,7 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv, mutex_init(&dev_priv->pps_mutex); i915_memcpy_init_early(dev_priv); + intel_runtime_pm_init_early(dev_priv); ret = i915_workqueues_init(dev_priv); if (ret < 0) @@ -1329,6 +1330,8 @@ static void i915_welcome_messages(struct drm_i915_private *dev_priv) DRM_INFO("DRM_I915_DEBUG enabled\n"); if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) DRM_INFO("DRM_I915_DEBUG_GEM enabled\n"); + if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_RPM)) + DRM_INFO("DRM_I915_DEBUG_RPM enabled\n"); } /** @@ -1477,7 +1480,7 @@ void i915_driver_unload(struct drm_device *dev) intel_display_power_put(dev_priv, POWER_DOMAIN_INIT); - WARN_ON(atomic_read(&dev_priv->runtime_pm.wakeref_count)); + intel_runtime_pm_cleanup(dev_priv); } static void i915_driver_release(struct drm_device *dev) @@ -1685,6 +1688,7 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation) out: enable_rpm_wakeref_asserts(dev_priv); + intel_runtime_pm_cleanup(dev_priv); return ret; } @@ -2644,7 +2648,7 @@ static int intel_runtime_suspend(struct device *kdev) } enable_rpm_wakeref_asserts(dev_priv); - WARN_ON_ONCE(atomic_read(&dev_priv->runtime_pm.wakeref_count)); + intel_runtime_pm_cleanup(dev_priv); if (intel_uncore_arm_unclaimed_mmio_detection(dev_priv)) DRM_ERROR("Unclaimed access detected prior to suspending\n"); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 0b10a30b7d96..c8d5b896b155 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -45,6 +45,7 @@ #include #include #include +#include #include #include @@ -1278,6 +1279,12 @@ struct i915_runtime_pm { atomic_t wakeref_count; bool suspended; bool irqs_enabled; + +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RPM) + spinlock_t debug_lock; + depot_stack_handle_t *debug_owners; + unsigned long debug_count; +#endif }; enum intel_pipe_crc_source { diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index dc6c0cec9b36..823db4ed47c8 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1947,6 +1947,7 @@ void intel_psr_short_pulse(struct intel_dp *intel_dp); int intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state); /* intel_runtime_pm.c */ +void intel_runtime_pm_init_early(struct drm_i915_private *dev_priv); int intel_power_domains_init(struct drm_i915_private *); void intel_power_domains_cleanup(struct drm_i915_private *dev_priv); void intel_power_domains_init_hw(struct drm_i915_private *dev_priv, bool resume); @@ -1957,6 +1958,7 @@ void bxt_display_core_init(struct drm_i915_private *dev_priv, bool resume); void bxt_display_core_uninit(struct drm_i915_private *dev_priv); void intel_runtime_pm_enable(struct drm_i915_private *dev_priv); void intel_runtime_pm_disable(struct drm_i915_private *dev_priv); +void intel_runtime_pm_cleanup(struct drm_i915_private *dev_priv); const char * intel_display_power_domain_str(enum intel_display_power_domain domain); @@ -1974,23 +1976,23 @@ void icl_dbuf_slices_update(struct drm_i915_private *dev_priv, u8 req_slices); static inline void -assert_rpm_device_not_suspended(struct drm_i915_private *dev_priv) +assert_rpm_device_not_suspended(struct drm_i915_private *i915) { - WARN_ONCE(dev_priv->runtime_pm.suspended, + WARN_ONCE(i915->runtime_pm.suspended, "Device suspended during HW access\n"); } static inline void -assert_rpm_wakelock_held(struct drm_i915_private *dev_priv) +assert_rpm_wakelock_held(struct drm_i915_private *i915) { - assert_rpm_device_not_suspended(dev_priv); - WARN_ONCE(!atomic_read(&dev_priv->runtime_pm.wakeref_count), + assert_rpm_device_not_suspended(i915); + WARN_ONCE(!atomic_read(&i915->runtime_pm.wakeref_count), "RPM wakelock ref not held during HW access"); } /** * disable_rpm_wakeref_asserts - disable the RPM assert checks - * @dev_priv: i915 device instance + * @i915: i915 device instance * * This function disable asserts that check if we hold an RPM wakelock * reference, while keeping the device-not-suspended checks still enabled. @@ -2007,14 +2009,14 @@ assert_rpm_wakelock_held(struct drm_i915_private *dev_priv) * enable_rpm_wakeref_asserts(). */ static inline void -disable_rpm_wakeref_asserts(struct drm_i915_private *dev_priv) +disable_rpm_wakeref_asserts(struct drm_i915_private *i915) { - atomic_inc(&dev_priv->runtime_pm.wakeref_count); + atomic_inc(&i915->runtime_pm.wakeref_count); } /** * enable_rpm_wakeref_asserts - re-enable the RPM assert checks - * @dev_priv: i915 device instance + * @i915: i915 device instance * * This function re-enables the RPM assert checks after disabling them with * disable_rpm_wakeref_asserts. It's meant to be used only in special @@ -2024,15 +2026,15 @@ disable_rpm_wakeref_asserts(struct drm_i915_private *dev_priv) * disable_rpm_wakeref_asserts(). */ static inline void -enable_rpm_wakeref_asserts(struct drm_i915_private *dev_priv) +enable_rpm_wakeref_asserts(struct drm_i915_private *i915) { - atomic_dec(&dev_priv->runtime_pm.wakeref_count); + atomic_dec(&i915->runtime_pm.wakeref_count); } -void intel_runtime_pm_get(struct drm_i915_private *dev_priv); -bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *dev_priv); -void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv); -void intel_runtime_pm_put(struct drm_i915_private *dev_priv); +void intel_runtime_pm_get(struct drm_i915_private *i915); +bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *i915); +void intel_runtime_pm_get_noresume(struct drm_i915_private *i915); +void intel_runtime_pm_put(struct drm_i915_private *i915); void intel_display_set_init_power(struct drm_i915_private *dev, bool enable); diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index b78c3b48aa62..8cc57eab862a 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -49,6 +49,143 @@ * present for a given platform. */ +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RPM) + +#include + +#define STACKDEPTH 8 + +static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ + spin_lock_init(&i915->runtime_pm.debug_lock); +} + +static noinline void +track_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ + struct i915_runtime_pm *rpm = &i915->runtime_pm; + unsigned long entries[STACKDEPTH]; + struct stack_trace trace = { + .entries = entries, + .max_entries = ARRAY_SIZE(entries), + .skip = 1 + }; + unsigned long flags; + depot_stack_handle_t stack, *stacks; + + if (!HAS_RUNTIME_PM(i915)) + return; + + save_stack_trace(&trace); + if (trace.nr_entries && + trace.entries[trace.nr_entries - 1] == ULONG_MAX) + trace.nr_entries--; + + stack = depot_save_stack(&trace, GFP_NOWAIT | __GFP_NOWARN); + if (!stack) + return; + + spin_lock_irqsave(&rpm->debug_lock, flags); + stacks = krealloc(rpm->debug_owners, + (rpm->debug_count + 1) * sizeof(*stacks), + GFP_NOWAIT | __GFP_NOWARN); + if (stacks) { + stacks[rpm->debug_count++] = stack; + rpm->debug_owners = stacks; + } + spin_unlock_irqrestore(&rpm->debug_lock, flags); +} + +static void untrack_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ + struct i915_runtime_pm *rpm = &i915->runtime_pm; + depot_stack_handle_t *stacks; + unsigned long flags; + + spin_lock_irqsave(&rpm->debug_lock, flags); + stacks = fetch_and_zero(&rpm->debug_owners); + rpm->debug_count = 0; + spin_unlock_irqrestore(&rpm->debug_lock, flags); + + kfree(stacks); +} + +static int cmphandle(const void *_a, const void *_b) +{ + const depot_stack_handle_t * const a = _a, * const b = _b; + + if (*a < *b) + return -1; + else if (*a > *b) + return 1; + else + return 0; +} + +static void show_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ + struct i915_runtime_pm *rpm = &i915->runtime_pm; + unsigned long entries[STACKDEPTH]; + depot_stack_handle_t *stacks; + unsigned long flags, count, i; + char *buf; + + spin_lock_irqsave(&rpm->debug_lock, flags); + stacks = fetch_and_zero(&rpm->debug_owners); + count = fetch_and_zero(&rpm->debug_count); + spin_unlock_irqrestore(&rpm->debug_lock, flags); + if (!count) + return; + + DRM_DEBUG_DRIVER("leaked %lu wakerefs\n", count); + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + goto out_stacks; + + sort(stacks, count, sizeof(*stacks), cmphandle, NULL); + + for (i = 0; i < count; i++) { + struct stack_trace trace = { + .entries = entries, + .max_entries = ARRAY_SIZE(entries), + }; + depot_stack_handle_t stack = stacks[i]; + unsigned long rep; + + rep = 1; + while (i + 1 < count && stacks[i + 1] == stack) + rep++, i++; + depot_fetch_stack(stack, &trace); + snprint_stack_trace(buf, PAGE_SIZE, &trace, 0); + DRM_DEBUG_DRIVER("wakeref x%lu at\n%s", rep, buf); + } + + kfree(buf); +out_stacks: + kfree(stacks); +} + +#else + +static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ +} + +static void track_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ +} + +static void untrack_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ +} + +static void show_intel_runtime_pm_wakeref(struct drm_i915_private *i915) +{ +} + +#endif + bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv, enum i915_power_well_id power_well_id); @@ -3920,7 +4057,7 @@ void intel_power_domains_verify_state(struct drm_i915_private *dev_priv) /** * intel_runtime_pm_get - grab a runtime pm reference - * @dev_priv: i915 device instance + * @i915: i915 device instance * * This function grabs a device-level runtime pm reference (mostly used for GEM * code to ensure the GTT or GT is on) and ensures that it is powered up. @@ -3928,22 +4065,24 @@ void intel_power_domains_verify_state(struct drm_i915_private *dev_priv) * Any runtime pm reference obtained by this function must have a symmetric * call to intel_runtime_pm_put() to release the reference again. */ -void intel_runtime_pm_get(struct drm_i915_private *dev_priv) +void intel_runtime_pm_get(struct drm_i915_private *i915) { - struct pci_dev *pdev = dev_priv->drm.pdev; + struct pci_dev *pdev = i915->drm.pdev; struct device *kdev = &pdev->dev; int ret; ret = pm_runtime_get_sync(kdev); WARN_ONCE(ret < 0, "pm_runtime_get_sync() failed: %d\n", ret); - atomic_inc(&dev_priv->runtime_pm.wakeref_count); - assert_rpm_wakelock_held(dev_priv); + atomic_inc(&i915->runtime_pm.wakeref_count); + assert_rpm_wakelock_held(i915); + + track_intel_runtime_pm_wakeref(i915); } /** * intel_runtime_pm_get_if_in_use - grab a runtime pm reference if device in use - * @dev_priv: i915 device instance + * @i915: i915 device instance * * This function grabs a device-level runtime pm reference if the device is * already in use and ensures that it is powered up. It is illegal to try @@ -3954,10 +4093,10 @@ void intel_runtime_pm_get(struct drm_i915_private *dev_priv) * * Returns: True if the wakeref was acquired, or False otherwise. */ -bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *dev_priv) +bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *i915) { if (IS_ENABLED(CONFIG_PM)) { - struct pci_dev *pdev = dev_priv->drm.pdev; + struct pci_dev *pdev = i915->drm.pdev; struct device *kdev = &pdev->dev; /* @@ -3970,15 +4109,17 @@ bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *dev_priv) return false; } - atomic_inc(&dev_priv->runtime_pm.wakeref_count); - assert_rpm_wakelock_held(dev_priv); + atomic_inc(&i915->runtime_pm.wakeref_count); + assert_rpm_wakelock_held(i915); + + track_intel_runtime_pm_wakeref(i915); return true; } /** * intel_runtime_pm_get_noresume - grab a runtime pm reference - * @dev_priv: i915 device instance + * @i915: i915 device instance * * This function grabs a device-level runtime pm reference (mostly used for GEM * code to ensure the GTT or GT is on). @@ -3993,32 +4134,35 @@ bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *dev_priv) * Any runtime pm reference obtained by this function must have a symmetric * call to intel_runtime_pm_put() to release the reference again. */ -void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv) +void intel_runtime_pm_get_noresume(struct drm_i915_private *i915) { - struct pci_dev *pdev = dev_priv->drm.pdev; + struct pci_dev *pdev = i915->drm.pdev; struct device *kdev = &pdev->dev; - assert_rpm_wakelock_held(dev_priv); + assert_rpm_wakelock_held(i915); pm_runtime_get_noresume(kdev); - atomic_inc(&dev_priv->runtime_pm.wakeref_count); + atomic_inc(&i915->runtime_pm.wakeref_count); + + track_intel_runtime_pm_wakeref(i915); } /** * intel_runtime_pm_put - release a runtime pm reference - * @dev_priv: i915 device instance + * @i915: i915 device instance * * This function drops the device-level runtime pm reference obtained by * intel_runtime_pm_get() and might power down the corresponding * hardware block right away if this is the last reference. */ -void intel_runtime_pm_put(struct drm_i915_private *dev_priv) +void intel_runtime_pm_put(struct drm_i915_private *i915) { - struct pci_dev *pdev = dev_priv->drm.pdev; + struct pci_dev *pdev = i915->drm.pdev; struct device *kdev = &pdev->dev; - assert_rpm_wakelock_held(dev_priv); - atomic_dec(&dev_priv->runtime_pm.wakeref_count); + assert_rpm_wakelock_held(i915); + if (atomic_dec_and_test(&i915->runtime_pm.wakeref_count)) + untrack_intel_runtime_pm_wakeref(i915); pm_runtime_mark_last_busy(kdev); pm_runtime_put_autosuspend(kdev); @@ -4026,7 +4170,7 @@ void intel_runtime_pm_put(struct drm_i915_private *dev_priv) /** * intel_runtime_pm_enable - enable runtime pm - * @dev_priv: i915 device instance + * @i915: i915 device instance * * This function enables runtime pm at the end of the driver load sequence. * @@ -4034,9 +4178,9 @@ void intel_runtime_pm_put(struct drm_i915_private *dev_priv) * subordinate display power domains. That is only done on the first modeset * using intel_display_set_init_power(). */ -void intel_runtime_pm_enable(struct drm_i915_private *dev_priv) +void intel_runtime_pm_enable(struct drm_i915_private *i915) { - struct pci_dev *pdev = dev_priv->drm.pdev; + struct pci_dev *pdev = i915->drm.pdev; struct device *kdev = &pdev->dev; pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */ @@ -4048,7 +4192,7 @@ void intel_runtime_pm_enable(struct drm_i915_private *dev_priv) * so the driver's own RPM reference tracking asserts also work on * platforms without RPM support. */ - if (!HAS_RUNTIME_PM(dev_priv)) { + if (!HAS_RUNTIME_PM(i915)) { int ret; pm_runtime_dont_use_autosuspend(kdev); @@ -4066,9 +4210,9 @@ void intel_runtime_pm_enable(struct drm_i915_private *dev_priv) pm_runtime_put_autosuspend(kdev); } -void intel_runtime_pm_disable(struct drm_i915_private *dev_priv) +void intel_runtime_pm_disable(struct drm_i915_private *i915) { - struct pci_dev *pdev = dev_priv->drm.pdev; + struct pci_dev *pdev = i915->drm.pdev; struct device *kdev = &pdev->dev; pm_runtime_dont_use_autosuspend(kdev); @@ -4077,6 +4221,25 @@ void intel_runtime_pm_disable(struct drm_i915_private *dev_priv) * Remove the refcount we took in intel_runtime_pm_enable() in case * the platform doesn't support runtime PM. */ - if (!HAS_RUNTIME_PM(dev_priv)) + if (!HAS_RUNTIME_PM(i915)) pm_runtime_put(kdev); } + +void intel_runtime_pm_cleanup(struct drm_i915_private *i915) +{ + struct i915_runtime_pm *rpm = &i915->runtime_pm; + + if (WARN(atomic_read(&rpm->wakeref_count), + "i915->runtime_pm.wakeref_count=%d on cleanup\n", + atomic_read(&rpm->wakeref_count))) { + show_intel_runtime_pm_wakeref(i915); + atomic_set(&rpm->wakeref_count, 0); + } + + untrack_intel_runtime_pm_wakeref(i915); +} + +void intel_runtime_pm_init_early(struct drm_i915_private *i915) +{ + init_intel_runtime_pm_wakeref(i915); +}