From patchwork Mon Jul 2 11:44:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10501215 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 693E260362 for ; Mon, 2 Jul 2018 11:45:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 56FB3287F9 for ; Mon, 2 Jul 2018 11:45:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 492B828827; Mon, 2 Jul 2018 11:45:01 +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 8AAAE287F9 for ; Mon, 2 Jul 2018 11:45:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1C33B6E3F5; Mon, 2 Jul 2018 11:45:00 +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 3991E6E3F5 for ; Mon, 2 Jul 2018 11:44:59 +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 12224718-1500050 for multiple; Mon, 02 Jul 2018 12:44:52 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 2 Jul 2018 12:44:52 +0100 Message-Id: <20180702114452.21098-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.18.0 Subject: [Intel-gfx] [PATCH] drm/i915: Show who pinned the pages when a leak is hit 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 Currently, we emit a warning when freeing an object if we do so with the pages still pinned (presumably as they are still in use somewhere). This only tells us that there is a problem, but doesn't tell us anything about the object or who might be pinning them and so provides no clue as to track down the problem. Let's try tracking everyone who pins the pages to see if we strike it lucky and catch the culprit red handed. References: https://bugs.freedesktop.org/show_bug.cgi?id=105360 Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/Kconfig.debug | 1 + drivers/gpu/drm/i915/i915_gem.c | 5 +- drivers/gpu/drm/i915/i915_gem_object.c | 109 +++++++++++++++++++++++++ drivers/gpu/drm/i915/i915_gem_object.h | 34 ++++++++ 4 files changed, 148 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug index 9de8b1c51a5c..84052becb279 100644 --- a/drivers/gpu/drm/i915/Kconfig.debug +++ b/drivers/gpu/drm/i915/Kconfig.debug @@ -43,6 +43,7 @@ config DRM_I915_DEBUG_GEM bool "Insert extra checks into the GEM internals" default n depends on DRM_I915_WERROR + select STACKDEPOT help Enable extra sanity checks (including BUGs) along the GEM driver paths that may slow the system down and if hit hang the machine. diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 8954db6ab083..e56240dc93f3 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2459,6 +2459,7 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj, if (!IS_ERR(pages)) obj->ops->put_pages(obj, pages); + untrack_i915_gem_object_pin_pages(obj); unlock: mutex_unlock(&obj->mm.lock); } @@ -4870,8 +4871,10 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915, if (obj->ops->release) obj->ops->release(obj); - if (WARN_ON(i915_gem_object_has_pinned_pages(obj))) + if (WARN_ON(i915_gem_object_has_pinned_pages(obj))) { + show_i915_gem_object_pin_pages(obj); atomic_set(&obj->mm.pages_pin_count, 0); + } __i915_gem_object_put_pages(obj, I915_MM_NORMAL); GEM_BUG_ON(i915_gem_object_has_pages(obj)); diff --git a/drivers/gpu/drm/i915/i915_gem_object.c b/drivers/gpu/drm/i915/i915_gem_object.c index aab8cdd80e6d..e1f60e4e17ce 100644 --- a/drivers/gpu/drm/i915/i915_gem_object.c +++ b/drivers/gpu/drm/i915/i915_gem_object.c @@ -25,6 +25,115 @@ #include "i915_drv.h" #include "i915_gem_object.h" +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) + +#include + +#define STACKDEPTH 12 + +void track_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) +{ + 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; + + 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); + if (!stack) + return; + + spin_lock_irqsave(&obj->mm.debug_lock, flags); + stacks = krealloc(obj->mm.debug_owners, + (obj->mm.debug_count + 1) * sizeof(*stacks), + GFP_NOWAIT); + if (stacks) { + stacks[obj->mm.debug_count++] = stack; + obj->mm.debug_owners = stacks; + } + spin_unlock_irqrestore(&obj->mm.debug_lock, flags); +} + +void untrack_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) +{ + depot_stack_handle_t *stacks; + unsigned long flags; + + spin_lock_irqsave(&obj->mm.debug_lock, flags); + stacks = fetch_and_zero(&obj->mm.debug_owners); + obj->mm.debug_count = 0; + spin_unlock_irqrestore(&obj->mm.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; +} + +void show_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) +{ + unsigned long entries[STACKDEPTH]; + depot_stack_handle_t *stacks; + unsigned long flags, count, i; + char *buf; + + spin_lock_irqsave(&obj->mm.debug_lock, flags); + stacks = fetch_and_zero(&obj->mm.debug_owners); + count = fetch_and_zero(&obj->mm.debug_count); + spin_unlock_irqrestore(&obj->mm.debug_lock, flags); + if (!count) + return; + + DRM_DEBUG_DRIVER("obj %p leaked pages, pinned %lu\n", obj, 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("obj %p pages pinned x%lu at\n%s", + obj, rep, buf); + } + + kfree(buf); +out_stacks: + kfree(stacks); +} + +#endif + /** * Mark up the object's coherency levels for a given cache_level * @obj: #drm_i915_gem_object diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h index c3c6f2e588fb..ebc2ee17426f 100644 --- a/drivers/gpu/drm/i915/i915_gem_object.h +++ b/drivers/gpu/drm/i915/i915_gem_object.h @@ -26,6 +26,9 @@ #define __I915_GEM_OBJECT_H__ #include +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) +#include +#endif #include #include @@ -245,6 +248,12 @@ struct drm_i915_gem_object { * swizzling. */ bool quirked:1; + +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) + spinlock_t debug_lock; + unsigned long debug_count; + depot_stack_handle_t *debug_owners; +#endif } mm; /** Breadcrumb of last rendering to the buffer. @@ -451,6 +460,31 @@ i915_gem_object_get_tile_row_size(struct drm_i915_gem_object *obj) int i915_gem_object_set_tiling(struct drm_i915_gem_object *obj, unsigned int tiling, unsigned int stride); +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) + +void track_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj); +void untrack_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj); +void show_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj); + +#else + +static inline void +track_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) +{ +} + +static inline void +untrack_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) +{ +} + +static inline void +show_i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) +{ +} + +#endif + static inline struct intel_engine_cs * i915_gem_object_last_write_engine(struct drm_i915_gem_object *obj) {