From patchwork Fri Feb 24 16:25:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrzej Hajda X-Patchwork-Id: 61400 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:5915:0:0:0:0:0 with SMTP id v21csp1020423wrd; Fri, 24 Feb 2023 08:53:56 -0800 (PST) X-Google-Smtp-Source: AK7set/Ty9UyU8UF+ITiOrqbdXbcno+AFAHKRnRF2tAzD1e7XDctSTdMo4q4ozdsPXGh718yahub X-Received: by 2002:a50:ed89:0:b0:4ac:c81d:149e with SMTP id h9-20020a50ed89000000b004acc81d149emr15947251edr.40.1677257636583; Fri, 24 Feb 2023 08:53:56 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1677257636; cv=none; d=google.com; s=arc-20160816; b=zKjt/qaIWhvHTqNfwVtY3akYaqxJn8pmYLXy00Ars/Ovpea/Pzg3oiFsEQi52CiKWJ zaZlk4/KxdE2rvsFXH4/t37IrYZWqBc9VsCQmh/5TDNMKqziHkq6hUFd2H7n6w8dQ0gt 4JN0aHrK3S2LDc/SzfJuCvl7mO0tgPD0TIJTEkYkP6tmU3wW8L7E20AqvIg7WuHdJW1t hvsp/xnlzHEspeUFfa6ygeTWBKxmvFRD9bVsilwIhJBBKVt9rCi2kxGFo8q3fJUB2xDa UN1WuMfgPY+c96t0hwPfX4kRIinkB7XPB5JiE9RzhODbe/PNuayHwVM85ezF5W0V9tgf hIvQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:in-reply-to:references:message-id :content-transfer-encoding:mime-version:subject:date:from :dkim-signature; bh=oEmXejUxbnnqADE5HTtjeFB0kWe/DfHIs7Yx/dq9nh0=; b=Xuz5BxI22a/9O5BomHrOmFdy+O8iIsX5ToD1kjdMhMYxkG7f9tPas1F2z14xVt4w9a jGff9y7UvLjyGGFKP4ravSTAdvFgF2DTy9CPMxf1ReezPSgK3SkihdofqXZ8D6FSiZvx LvQdDFpjATcyKg39plKIPZgzzOhM/N0IZ4lKZ/PsU+ozlQt0J+suzpMFY5VCKGhv6Ops 4I4/9GWra09Y+y9lhdl1v2woCe8sBQuSrmHrBbK24HHI2OvbHmLiovRZFQUiCkE6RU3o 2vkMY5DrieLtXfs0rIEuo25MUYdcH+26kLOjVGRdfdzGVP+dVVU23+aib/IYIpAq43cC EIFA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=lVB2R7TC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id z10-20020aa7c64a000000b004ace5d2cec7si15462116edr.73.2023.02.24.08.53.31; Fri, 24 Feb 2023 08:53:56 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=lVB2R7TC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229641AbjBXQ0h (ORCPT + 99 others); Fri, 24 Feb 2023 11:26:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229605AbjBXQ0f (ORCPT ); Fri, 24 Feb 2023 11:26:35 -0500 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D72BA6A7A9 for ; Fri, 24 Feb 2023 08:26:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677255992; x=1708791992; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=FFUgPWNuEjail52Mg5EAExBxGFOAfX1/frDyd8NTZb0=; b=lVB2R7TCoHedRc4jal4NEZ24kTkXc7HLKq8n2BdhwHr50wOQeYiNvupR ixRBj9pphKhul8XjDMlt5XYzSGP9UfZO4ipVGsUMAdQfddurnBHx5bdEb AIrEEhlwQnjzeUIj6eRdTbfmxKPPeH95lXJR3EYMT/WP6m/LHM62F9Gn3 DsJBBz88xuu5HKGO3l2PxAwlmet2WY7BpRFCYv3n66iQG+3acBL26jvfN Oj+3qv5B2JTotKiLbCHIQSHqHQfZ8MfVe2n95eN071jOc98m6/OTp0lZP CEt6L5RlzjPe+7IbmEKzkC2i7AI/V46LKiyV1jm5i5ff71dgFG0Qz2rQo A==; X-IronPort-AV: E=McAfee;i="6500,9779,10631"; a="317273356" X-IronPort-AV: E=Sophos;i="5.97,325,1669104000"; d="scan'208";a="317273356" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2023 08:26:19 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10631"; a="705321773" X-IronPort-AV: E=Sophos;i="5.97,325,1669104000"; d="scan'208";a="705321773" Received: from lab-ah.igk.intel.com ([10.102.42.211]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2023 08:26:15 -0800 From: Andrzej Hajda Date: Fri, 24 Feb 2023 17:25:40 +0100 Subject: [PATCH 1/3] drm/i915: Separate wakeref tracking MIME-Version: 1.0 Message-Id: <20230224-track_gt-v1-1-0222096fcdc6@intel.com> References: <20230224-track_gt-v1-0-0222096fcdc6@intel.com> In-Reply-To: <20230224-track_gt-v1-0-0222096fcdc6@intel.com> To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Daniel Vetter Cc: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Chris Wilson , Andrzej Hajda , Chris Wilson X-Mailer: b4 0.11.1 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE, SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1758732103828711285?= X-GMAIL-MSGID: =?utf-8?q?1758732103828711285?= From: Chris Wilson Extract the callstack tracking of intel_runtime_pm.c into its own utility so that that we can reuse it for other online debugging of scoped wakerefs. Signed-off-by: Chris Wilson Signed-off-by: Andrzej Hajda --- drivers/gpu/drm/i915/Kconfig.debug | 9 + drivers/gpu/drm/i915/Makefile | 4 + drivers/gpu/drm/i915/intel_runtime_pm.c | 244 +++------------------------ drivers/gpu/drm/i915/intel_runtime_pm.h | 10 +- drivers/gpu/drm/i915/intel_wakeref.h | 6 +- drivers/gpu/drm/i915/intel_wakeref_tracker.c | 234 +++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_wakeref_tracker.h | 76 +++++++++ 7 files changed, 355 insertions(+), 228 deletions(-) diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug index 93dfb7ed970547..5fde52107e3b44 100644 --- a/drivers/gpu/drm/i915/Kconfig.debug +++ b/drivers/gpu/drm/i915/Kconfig.debug @@ -25,6 +25,7 @@ config DRM_I915_DEBUG select PREEMPT_COUNT select I2C_CHARDEV select STACKDEPOT + select STACKTRACE select DRM_DP_AUX_CHARDEV select X86_MSR # used by igt/pm_rpm select DRM_VGEM # used by igt/prime_vgem (dmabuf interop checks) @@ -37,6 +38,7 @@ config DRM_I915_DEBUG select DRM_I915_DEBUG_GEM select DRM_I915_DEBUG_GEM_ONCE select DRM_I915_DEBUG_MMIO + select DRM_I915_TRACK_WAKEREF select DRM_I915_DEBUG_RUNTIME_PM select DRM_I915_SW_FENCE_DEBUG_OBJECTS select DRM_I915_SELFTEST @@ -227,11 +229,18 @@ config DRM_I915_DEBUG_VBLANK_EVADE If in doubt, say "N". +config DRM_I915_TRACK_WAKEREF + depends on STACKDEPOT + depends on STACKTRACE + bool + config DRM_I915_DEBUG_RUNTIME_PM bool "Enable extra state checking for runtime PM" depends on DRM_I915 default n select STACKDEPOT + select STACKTRACE + select DRM_I915_TRACK_WAKEREF help Choose this option to turn on extra state checking for the runtime PM functionality. This may introduce overhead during diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index b2f91a1f826858..42daff6d575a82 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -81,6 +81,10 @@ i915-$(CONFIG_DEBUG_FS) += \ i915_debugfs_params.o \ display/intel_display_debugfs.o \ display/intel_pipe_crc.o + +i915-$(CONFIG_DRM_I915_TRACK_WAKEREF) += \ + intel_wakeref_tracker.o + i915-$(CONFIG_PERF_EVENTS) += i915_pmu.o # "Graphics Technology" (aka we talk to the gpu) diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index 129746713d072f..72887e2bb03c21 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -52,182 +52,37 @@ #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) -#include - -#define STACKDEPTH 8 - -static noinline depot_stack_handle_t __save_depot_stack(void) -{ - unsigned long entries[STACKDEPTH]; - unsigned int n; - - n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); - return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN); -} - static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm) { - spin_lock_init(&rpm->debug.lock); - stack_depot_init(); + intel_wakeref_tracker_init(&rpm->debug); } -static noinline depot_stack_handle_t +static intel_wakeref_t track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm) { - depot_stack_handle_t stack, *stacks; - unsigned long flags; - - if (rpm->no_wakeref_tracking) - return -1; - - stack = __save_depot_stack(); - if (!stack) + if (!rpm->available) return -1; - spin_lock_irqsave(&rpm->debug.lock, flags); - - if (!rpm->debug.count) - rpm->debug.last_acquire = stack; - - 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; - } else { - stack = -1; - } - - spin_unlock_irqrestore(&rpm->debug.lock, flags); - - return stack; + return intel_wakeref_tracker_add(&rpm->debug); } static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, - depot_stack_handle_t stack) + intel_wakeref_t wakeref) { - struct drm_i915_private *i915 = container_of(rpm, - struct drm_i915_private, - runtime_pm); - unsigned long flags, n; - bool found = false; - - if (unlikely(stack == -1)) - return; - - spin_lock_irqsave(&rpm->debug.lock, flags); - for (n = rpm->debug.count; n--; ) { - if (rpm->debug.owners[n] == stack) { - memmove(rpm->debug.owners + n, - rpm->debug.owners + n + 1, - (--rpm->debug.count - n) * sizeof(stack)); - found = true; - break; - } - } - spin_unlock_irqrestore(&rpm->debug.lock, flags); - - if (drm_WARN(&i915->drm, !found, - "Unmatched wakeref (tracking %lu), count %u\n", - rpm->debug.count, atomic_read(&rpm->wakeref_count))) { - char *buf; - - buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN); - if (!buf) - return; - - stack_depot_snprint(stack, buf, PAGE_SIZE, 2); - DRM_DEBUG_DRIVER("wakeref %x from\n%s", stack, buf); - - stack = READ_ONCE(rpm->debug.last_release); - if (stack) { - stack_depot_snprint(stack, buf, PAGE_SIZE, 2); - DRM_DEBUG_DRIVER("wakeref last released at\n%s", buf); - } - - kfree(buf); - } + intel_wakeref_tracker_remove(&rpm->debug, wakeref); } -static int cmphandle(const void *_a, const void *_b) +static void untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm) { - const depot_stack_handle_t * const a = _a, * const b = _b; + struct drm_printer p = drm_debug_printer("i915"); - if (*a < *b) - return -1; - else if (*a > *b) - return 1; - else - return 0; -} - -static void -__print_intel_runtime_pm_wakeref(struct drm_printer *p, - const struct intel_runtime_pm_debug *dbg) -{ - unsigned long i; - char *buf; - - buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN); - if (!buf) - return; - - if (dbg->last_acquire) { - stack_depot_snprint(dbg->last_acquire, buf, PAGE_SIZE, 2); - drm_printf(p, "Wakeref last acquired:\n%s", buf); - } - - if (dbg->last_release) { - stack_depot_snprint(dbg->last_release, buf, PAGE_SIZE, 2); - drm_printf(p, "Wakeref last released:\n%s", buf); - } - - drm_printf(p, "Wakeref count: %lu\n", dbg->count); - - sort(dbg->owners, dbg->count, sizeof(*dbg->owners), cmphandle, NULL); - - for (i = 0; i < dbg->count; i++) { - depot_stack_handle_t stack = dbg->owners[i]; - unsigned long rep; - - rep = 1; - while (i + 1 < dbg->count && dbg->owners[i + 1] == stack) - rep++, i++; - stack_depot_snprint(stack, buf, PAGE_SIZE, 2); - drm_printf(p, "Wakeref x%lu taken at:\n%s", rep, buf); - } - - kfree(buf); -} - -static noinline void -__untrack_all_wakerefs(struct intel_runtime_pm_debug *debug, - struct intel_runtime_pm_debug *saved) -{ - *saved = *debug; - - debug->owners = NULL; - debug->count = 0; - debug->last_release = __save_depot_stack(); -} - -static void -dump_and_free_wakeref_tracking(struct intel_runtime_pm_debug *debug) -{ - if (debug->count) { - struct drm_printer p = drm_debug_printer("i915"); - - __print_intel_runtime_pm_wakeref(&p, debug); - } - - kfree(debug->owners); + intel_wakeref_tracker_reset(&rpm->debug, &p); } static noinline void __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm) { - struct intel_runtime_pm_debug dbg = {}; + struct intel_wakeref_tracker saved; unsigned long flags; if (!atomic_dec_and_lock_irqsave(&rpm->wakeref_count, @@ -235,60 +90,21 @@ __intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm) flags)) return; - __untrack_all_wakerefs(&rpm->debug, &dbg); + saved = __intel_wakeref_tracker_reset(&rpm->debug); spin_unlock_irqrestore(&rpm->debug.lock, flags); - dump_and_free_wakeref_tracking(&dbg); -} - -static noinline void -untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm) -{ - struct intel_runtime_pm_debug dbg = {}; - unsigned long flags; - - spin_lock_irqsave(&rpm->debug.lock, flags); - __untrack_all_wakerefs(&rpm->debug, &dbg); - spin_unlock_irqrestore(&rpm->debug.lock, flags); + if (saved.count) { + struct drm_printer p = drm_debug_printer("i915"); - dump_and_free_wakeref_tracking(&dbg); + __intel_wakeref_tracker_show(&saved, &p); + intel_wakeref_tracker_fini(&saved); + } } void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, struct drm_printer *p) { - struct intel_runtime_pm_debug dbg = {}; - - do { - unsigned long alloc = dbg.count; - depot_stack_handle_t *s; - - spin_lock_irq(&rpm->debug.lock); - dbg.count = rpm->debug.count; - if (dbg.count <= alloc) { - memcpy(dbg.owners, - rpm->debug.owners, - dbg.count * sizeof(*s)); - } - dbg.last_acquire = rpm->debug.last_acquire; - dbg.last_release = rpm->debug.last_release; - spin_unlock_irq(&rpm->debug.lock); - if (dbg.count <= alloc) - break; - - s = krealloc(dbg.owners, - dbg.count * sizeof(*s), - GFP_NOWAIT | __GFP_NOWARN); - if (!s) - goto out; - - dbg.owners = s; - } while (1); - - __print_intel_runtime_pm_wakeref(p, &dbg); - -out: - kfree(dbg.owners); + intel_wakeref_tracker_show(&rpm->debug, p); } #else @@ -297,14 +113,14 @@ static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm) { } -static depot_stack_handle_t +static intel_wakeref_t track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm) { return -1; } static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm, - intel_wakeref_t wref) + intel_wakeref_t wakeref) { } @@ -349,9 +165,8 @@ intel_runtime_pm_release(struct intel_runtime_pm *rpm, int wakelock) static intel_wakeref_t __intel_runtime_pm_get(struct intel_runtime_pm *rpm, bool wakelock) { - struct drm_i915_private *i915 = container_of(rpm, - struct drm_i915_private, - runtime_pm); + struct drm_i915_private *i915 = + container_of(rpm, struct drm_i915_private, runtime_pm); int ret; ret = pm_runtime_get_sync(rpm->kdev); @@ -556,9 +371,8 @@ void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref) */ void intel_runtime_pm_enable(struct intel_runtime_pm *rpm) { - struct drm_i915_private *i915 = container_of(rpm, - struct drm_i915_private, - runtime_pm); + struct drm_i915_private *i915 = + container_of(rpm, struct drm_i915_private, runtime_pm); struct device *kdev = rpm->kdev; /* @@ -611,9 +425,8 @@ void intel_runtime_pm_enable(struct intel_runtime_pm *rpm) void intel_runtime_pm_disable(struct intel_runtime_pm *rpm) { - struct drm_i915_private *i915 = container_of(rpm, - struct drm_i915_private, - runtime_pm); + struct drm_i915_private *i915 = + container_of(rpm, struct drm_i915_private, runtime_pm); struct device *kdev = rpm->kdev; /* Transfer rpm ownership back to core */ @@ -628,9 +441,8 @@ void intel_runtime_pm_disable(struct intel_runtime_pm *rpm) void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm) { - struct drm_i915_private *i915 = container_of(rpm, - struct drm_i915_private, - runtime_pm); + struct drm_i915_private *i915 = + container_of(rpm, struct drm_i915_private, runtime_pm); int count = atomic_read(&rpm->wakeref_count); intel_wakeref_auto_fini(&rpm->userfault_wakeref); @@ -646,7 +458,7 @@ void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm) void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm) { struct drm_i915_private *i915 = - container_of(rpm, struct drm_i915_private, runtime_pm); + container_of(rpm, struct drm_i915_private, runtime_pm); struct pci_dev *pdev = to_pci_dev(i915->drm.dev); struct device *kdev = &pdev->dev; diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.h b/drivers/gpu/drm/i915/intel_runtime_pm.h index e592e8d6499a1f..a8dc2baf79844f 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.h +++ b/drivers/gpu/drm/i915/intel_runtime_pm.h @@ -83,15 +83,7 @@ struct intel_runtime_pm { * paired rpm_put) we can remove corresponding pairs of and keep * the array trimmed to active wakerefs. */ - struct intel_runtime_pm_debug { - spinlock_t lock; - - depot_stack_handle_t last_acquire; - depot_stack_handle_t last_release; - - depot_stack_handle_t *owners; - unsigned long count; - } debug; + struct intel_wakeref_tracker debug; #endif }; diff --git a/drivers/gpu/drm/i915/intel_wakeref.h b/drivers/gpu/drm/i915/intel_wakeref.h index 71b8a63f6f104d..20720fbcc28d46 100644 --- a/drivers/gpu/drm/i915/intel_wakeref.h +++ b/drivers/gpu/drm/i915/intel_wakeref.h @@ -17,7 +17,9 @@ #include #include -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG) +#include "intel_wakeref_tracker.h" + +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_WAKEREF) #define INTEL_WAKEREF_BUG_ON(expr) BUG_ON(expr) #else #define INTEL_WAKEREF_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr) @@ -26,8 +28,6 @@ struct intel_runtime_pm; struct intel_wakeref; -typedef depot_stack_handle_t intel_wakeref_t; - struct intel_wakeref_ops { int (*get)(struct intel_wakeref *wf); int (*put)(struct intel_wakeref *wf); diff --git a/drivers/gpu/drm/i915/intel_wakeref_tracker.c b/drivers/gpu/drm/i915/intel_wakeref_tracker.c new file mode 100644 index 00000000000000..a0bcef13a1085a --- /dev/null +++ b/drivers/gpu/drm/i915/intel_wakeref_tracker.c @@ -0,0 +1,234 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2021 Intel Corporation + */ + +#include +#include +#include +#include + +#include + +#include "intel_wakeref.h" + +#define STACKDEPTH 8 + +static noinline depot_stack_handle_t __save_depot_stack(void) +{ + unsigned long entries[STACKDEPTH]; + unsigned int n; + + n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); + return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN); +} + +static void __print_depot_stack(depot_stack_handle_t stack, + char *buf, int sz, int indent) +{ + unsigned long *entries; + unsigned int nr_entries; + + nr_entries = stack_depot_fetch(stack, &entries); + stack_trace_snprint(buf, sz, entries, nr_entries, indent); +} + +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 +__intel_wakeref_tracker_show(const struct intel_wakeref_tracker *w, + struct drm_printer *p) +{ + unsigned long i; + char *buf; + + buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN); + if (!buf) + return; + + if (w->last_acquire) { + __print_depot_stack(w->last_acquire, buf, PAGE_SIZE, 2); + drm_printf(p, "Wakeref last acquired:\n%s", buf); + } + + if (w->last_release) { + __print_depot_stack(w->last_release, buf, PAGE_SIZE, 2); + drm_printf(p, "Wakeref last released:\n%s", buf); + } + + drm_printf(p, "Wakeref count: %lu\n", w->count); + + sort(w->owners, w->count, sizeof(*w->owners), cmphandle, NULL); + + for (i = 0; i < w->count; i++) { + depot_stack_handle_t stack = w->owners[i]; + unsigned long rep; + + rep = 1; + while (i + 1 < w->count && w->owners[i + 1] == stack) + rep++, i++; + __print_depot_stack(stack, buf, PAGE_SIZE, 2); + drm_printf(p, "Wakeref x%lu taken at:\n%s", rep, buf); + } + + kfree(buf); +} + +void intel_wakeref_tracker_show(struct intel_wakeref_tracker *w, + struct drm_printer *p) +{ + struct intel_wakeref_tracker tmp = {}; + + do { + unsigned long alloc = tmp.count; + depot_stack_handle_t *s; + + spin_lock_irq(&w->lock); + tmp.count = w->count; + if (tmp.count <= alloc) + memcpy(tmp.owners, w->owners, tmp.count * sizeof(*s)); + tmp.last_acquire = w->last_acquire; + tmp.last_release = w->last_release; + spin_unlock_irq(&w->lock); + if (tmp.count <= alloc) + break; + + s = krealloc(tmp.owners, + tmp.count * sizeof(*s), + GFP_NOWAIT | __GFP_NOWARN); + if (!s) + goto out; + + tmp.owners = s; + } while (1); + + __intel_wakeref_tracker_show(&tmp, p); + +out: + intel_wakeref_tracker_fini(&tmp); +} + +intel_wakeref_t intel_wakeref_tracker_add(struct intel_wakeref_tracker *w) +{ + depot_stack_handle_t stack, *stacks; + unsigned long flags; + + stack = __save_depot_stack(); + if (!stack) + return -1; + + spin_lock_irqsave(&w->lock, flags); + + if (!w->count) + w->last_acquire = stack; + + stacks = krealloc(w->owners, + (w->count + 1) * sizeof(*stacks), + GFP_NOWAIT | __GFP_NOWARN); + if (stacks) { + stacks[w->count++] = stack; + w->owners = stacks; + } else { + stack = -1; + } + + spin_unlock_irqrestore(&w->lock, flags); + + return stack; +} + +void intel_wakeref_tracker_remove(struct intel_wakeref_tracker *w, + intel_wakeref_t stack) +{ + unsigned long flags, n; + bool found = false; + + if (unlikely(stack == -1)) + return; + + spin_lock_irqsave(&w->lock, flags); + for (n = w->count; n--; ) { + if (w->owners[n] == stack) { + memmove(w->owners + n, + w->owners + n + 1, + (--w->count - n) * sizeof(stack)); + found = true; + break; + } + } + spin_unlock_irqrestore(&w->lock, flags); + + if (WARN(!found, + "Unmatched wakeref %x, tracking %lu\n", + stack, w->count)) { + char *buf; + + buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN); + if (!buf) + return; + + __print_depot_stack(stack, buf, PAGE_SIZE, 2); + pr_err("wakeref %x from\n%s", stack, buf); + + stack = READ_ONCE(w->last_release); + if (stack && !w->count) { + __print_depot_stack(stack, buf, PAGE_SIZE, 2); + pr_err("wakeref last released at\n%s", buf); + } + + kfree(buf); + } +} + +struct intel_wakeref_tracker +__intel_wakeref_tracker_reset(struct intel_wakeref_tracker *w) +{ + struct intel_wakeref_tracker saved; + + lockdep_assert_held(&w->lock); + + saved = *w; + + w->owners = NULL; + w->count = 0; + w->last_release = __save_depot_stack(); + + return saved; +} + +void intel_wakeref_tracker_reset(struct intel_wakeref_tracker *w, + struct drm_printer *p) +{ + struct intel_wakeref_tracker tmp; + + spin_lock_irq(&w->lock); + tmp = __intel_wakeref_tracker_reset(w); + spin_unlock_irq(&w->lock); + + if (tmp.count) + __intel_wakeref_tracker_show(&tmp, p); + + intel_wakeref_tracker_fini(&tmp); +} + +void intel_wakeref_tracker_init(struct intel_wakeref_tracker *w) +{ + memset(w, 0, sizeof(*w)); + spin_lock_init(&w->lock); + stack_depot_init(); +} + +void intel_wakeref_tracker_fini(struct intel_wakeref_tracker *w) +{ + kfree(w->owners); +} diff --git a/drivers/gpu/drm/i915/intel_wakeref_tracker.h b/drivers/gpu/drm/i915/intel_wakeref_tracker.h new file mode 100644 index 00000000000000..61df68e28c0fbf --- /dev/null +++ b/drivers/gpu/drm/i915/intel_wakeref_tracker.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright © 2019 Intel Corporation + */ + +#ifndef INTEL_WAKEREF_TRACKER_H +#define INTEL_WAKEREF_TRACKER_H + +#include +#include +#include + +typedef depot_stack_handle_t intel_wakeref_t; + +struct drm_printer; + +struct intel_wakeref_tracker { + spinlock_t lock; + + depot_stack_handle_t last_acquire; + depot_stack_handle_t last_release; + + depot_stack_handle_t *owners; + unsigned long count; +}; + +#if IS_ENABLED(CONFIG_DRM_I915_TRACK_WAKEREF) + +void intel_wakeref_tracker_init(struct intel_wakeref_tracker *w); +void intel_wakeref_tracker_fini(struct intel_wakeref_tracker *w); + +intel_wakeref_t intel_wakeref_tracker_add(struct intel_wakeref_tracker *w); +void intel_wakeref_tracker_remove(struct intel_wakeref_tracker *w, + intel_wakeref_t handle); + +struct intel_wakeref_tracker +__intel_wakeref_tracker_reset(struct intel_wakeref_tracker *w); +void intel_wakeref_tracker_reset(struct intel_wakeref_tracker *w, + struct drm_printer *p); + +void __intel_wakeref_tracker_show(const struct intel_wakeref_tracker *w, + struct drm_printer *p); +void intel_wakeref_tracker_show(struct intel_wakeref_tracker *w, + struct drm_printer *p); + +#else + +static inline void intel_wakeref_tracker_init(struct intel_wakeref_tracker *w) {} +static inline void intel_wakeref_tracker_fini(struct intel_wakeref_tracker *w) {} + +static inline intel_wakeref_t +intel_wakeref_tracker_add(struct intel_wakeref_tracker *w) +{ + return -1; +} + +static inline void +intel_wakeref_untrack_remove(struct intel_wakeref_tracker *w, intel_wakeref_t handle) {} + +static inline struct intel_wakeref_tracker +__intel_wakeref_tracker_reset(struct intel_wakeref_tracker *w) +{ + return (struct intel_wakeref_tracker){}; +} + +static inline void intel_wakeref_tracker_reset(struct intel_wakeref_tracker *w, + struct drm_printer *p) +{ +} + +static inline void __intel_wakeref_tracker_show(const struct intel_wakeref_tracker *w, struct drm_printer *p) {} +static inline void intel_wakeref_tracker_show(struct intel_wakeref_tracker *w, struct drm_printer *p) {} + +#endif + +#endif /* INTEL_WAKEREF_TRACKER_H */