From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C674C352A4 for ; Mon, 10 Feb 2020 20:57:42 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 666B820715 for ; Mon, 10 Feb 2020 20:57:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 666B820715 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A0F586E9F2; Mon, 10 Feb 2020 20:57:39 +0000 (UTC) Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8437E6E9EE for ; Mon, 10 Feb 2020 20:57:38 +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 20180247-1500050 for multiple; Mon, 10 Feb 2020 20:57:23 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 10 Feb 2020 20:57:19 +0000 Message-Id: <20200210205722.794180-4-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210205722.794180-1-chris@chris-wilson.co.uk> References: <20200210205722.794180-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 4/7] drm/i915/gem: Don't leak non-persistent requests on changing engines X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" If we have a set of active engines marked as being non-persistent, we lose track of those if the user replaces those engines with I915_CONTEXT_PARAM_ENGINES. As part of our uABI contract is that non-persistent requests are terminated if they are no longer being tracked by the user's context (in order to prevent a lost request causing an untracked and so unstoppable GPU hang), we need to apply the same context cancellation upon changing engines. v2: Track stale engines[] so we only reap at context closure. Fixes: a0e047156cde ("drm/i915/gem: Make context persistence optional") Testcase: igt/gem_ctx_peristence/replace Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 118 ++++++++++++++++-- .../gpu/drm/i915/gem/i915_gem_context_types.h | 13 +- drivers/gpu/drm/i915/i915_sw_fence.c | 19 ++- drivers/gpu/drm/i915/i915_sw_fence.h | 2 +- 4 files changed, 139 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index cfaf5bbdbcab..ba29462bd501 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -270,7 +270,8 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx) if (!e) return ERR_PTR(-ENOMEM); - init_rcu_head(&e->rcu); + e->ctx = ctx; + for_each_engine(engine, gt, id) { struct intel_context *ce; @@ -450,7 +451,7 @@ static struct intel_engine_cs *active_engine(struct intel_context *ce) return engine; } -static void kill_context(struct i915_gem_context *ctx) +static void kill_engines(struct i915_gem_engines *engines) { struct i915_gem_engines_iter it; struct intel_context *ce; @@ -462,7 +463,7 @@ static void kill_context(struct i915_gem_context *ctx) * However, we only care about pending requests, so only include * engines on which there are incomplete requests. */ - for_each_gem_engine(ce, __context_engines_static(ctx), it) { + for_each_gem_engine(ce, engines, it) { struct intel_engine_cs *engine; if (intel_context_set_banned(ce)) @@ -484,10 +485,41 @@ static void kill_context(struct i915_gem_context *ctx) * the context from the GPU, we have to resort to a full * reset. We hope the collateral damage is worth it. */ - __reset_context(ctx, engine); + __reset_context(engines->ctx, engine); } } +static void kill_stale_engines(struct i915_gem_context *ctx) +{ + struct i915_gem_engines *pos, *next; + unsigned long flags; + + spin_lock_irqsave(&ctx->stale.lock, flags); + list_for_each_entry_safe(pos, next, &ctx->stale.engines, link) { + if (!i915_sw_fence_await(&pos->fence)) + continue; + + spin_unlock_irqrestore(&ctx->stale.lock, flags); + + kill_engines(pos); + + spin_lock_irqsave(&ctx->stale.lock, flags); + list_safe_reset_next(pos, next, link); + list_del_init(&pos->link); /* decouple from FENCE_COMPLETE */ + + i915_sw_fence_complete(&pos->fence); + } + spin_unlock_irqrestore(&ctx->stale.lock, flags); +} + +static void kill_context(struct i915_gem_context *ctx) +{ + if (!list_empty(&ctx->stale.engines)) + kill_stale_engines(ctx); + + kill_engines(__context_engines_static(ctx)); +} + static void set_closed_name(struct i915_gem_context *ctx) { char *s; @@ -602,6 +634,9 @@ __create_context(struct drm_i915_private *i915) ctx->sched.priority = I915_USER_PRIORITY(I915_PRIORITY_NORMAL); mutex_init(&ctx->mutex); + spin_lock_init(&ctx->stale.lock); + INIT_LIST_HEAD(&ctx->stale.engines); + mutex_init(&ctx->engines_mutex); e = default_engines(ctx); if (IS_ERR(e)) { @@ -1529,6 +1564,71 @@ static const i915_user_extension_fn set_engines__extensions[] = { [I915_CONTEXT_ENGINES_EXT_BOND] = set_engines__bond, }; +static int engines_notify(struct i915_sw_fence *fence, + enum i915_sw_fence_notify state) +{ + struct i915_gem_engines *engines = + container_of(fence, typeof(*engines), fence); + + switch (state) { + case FENCE_COMPLETE: + if (!list_empty(&engines->link)) { + struct i915_gem_context *ctx = engines->ctx; + unsigned long flags; + + spin_lock_irqsave(&ctx->stale.lock, flags); + list_del(&engines->link); + spin_unlock_irqrestore(&ctx->stale.lock, flags); + } + break; + + case FENCE_FREE: + init_rcu_head(&engines->rcu); + call_rcu(&engines->rcu, free_engines_rcu); + break; + } + + return NOTIFY_DONE; +} + +static void engines_idle_release(struct i915_gem_engines *engines) +{ + struct i915_gem_engines_iter it; + struct intel_context *ce; + unsigned long flags; + + GEM_BUG_ON(!engines); + i915_sw_fence_init(&engines->fence, engines_notify); + + spin_lock_irqsave(&engines->ctx->stale.lock, flags); + list_add(&engines->link, &engines->ctx->stale.engines); + spin_unlock_irqrestore(&engines->ctx->stale.lock, flags); + + for_each_gem_engine(ce, engines, it) { + struct dma_fence *fence; + int err; + + if (!ce->timeline) + continue; + + fence = i915_active_fence_get(&ce->timeline->last_request); + if (!fence) + continue; + + err = i915_sw_fence_await_dma_fence(&engines->fence, + fence, 0, + GFP_KERNEL); + + dma_fence_put(fence); + if (err < 0) { + kill_engines(engines); + break; + } + } + + i915_sw_fence_commit(&engines->fence); +} + static int set_engines(struct i915_gem_context *ctx, const struct drm_i915_gem_context_param *args) @@ -1571,7 +1671,8 @@ set_engines(struct i915_gem_context *ctx, if (!set.engines) return -ENOMEM; - init_rcu_head(&set.engines->rcu); + set.engines->ctx = ctx; + for (n = 0; n < num_engines; n++) { struct i915_engine_class_instance ci; struct intel_engine_cs *engine; @@ -1631,7 +1732,8 @@ set_engines(struct i915_gem_context *ctx, set.engines = rcu_replace_pointer(ctx->engines, set.engines, 1); mutex_unlock(&ctx->engines_mutex); - call_rcu(&set.engines->rcu, free_engines_rcu); + /* Keep track of old engine sets for kill_context() */ + engines_idle_release(set.engines); return 0; } @@ -1646,7 +1748,6 @@ __copy_engines(struct i915_gem_engines *e) if (!copy) return ERR_PTR(-ENOMEM); - init_rcu_head(©->rcu); for (n = 0; n < e->num_engines; n++) { if (e->engines[n]) copy->engines[n] = intel_context_get(e->engines[n]); @@ -1890,7 +1991,8 @@ static int clone_engines(struct i915_gem_context *dst, if (!clone) goto err_unlock; - init_rcu_head(&clone->rcu); + clone->ctx = dst; + for (n = 0; n < e->num_engines; n++) { struct intel_engine_cs *engine; diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h index 017ca803ab47..8d996dde8046 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h @@ -20,6 +20,7 @@ #include "gt/intel_context_types.h" #include "i915_scheduler.h" +#include "i915_sw_fence.h" struct pid; @@ -30,7 +31,12 @@ struct intel_timeline; struct intel_ring; struct i915_gem_engines { - struct rcu_head rcu; + union { + struct rcu_head rcu; + struct list_head link; + }; + struct i915_sw_fence fence; + struct i915_gem_context *ctx; unsigned int num_engines; struct intel_context *engines[]; }; @@ -173,6 +179,11 @@ struct i915_gem_context { * context in messages. */ char name[TASK_COMM_LEN + 8]; + + struct { + struct spinlock lock; + struct list_head engines; + } stale; }; #endif /* __I915_GEM_CONTEXT_TYPES_H__ */ diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c index 51ba97daf2a0..bc6d4f8b78f0 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence.c +++ b/drivers/gpu/drm/i915/i915_sw_fence.c @@ -211,10 +211,23 @@ void i915_sw_fence_complete(struct i915_sw_fence *fence) __i915_sw_fence_complete(fence, NULL); } -void i915_sw_fence_await(struct i915_sw_fence *fence) +bool i915_sw_fence_await(struct i915_sw_fence *fence) { - debug_fence_assert(fence); - WARN_ON(atomic_inc_return(&fence->pending) <= 1); + int old, new; + + /* + * It is only safe to add a new await to the fence while it has + * not yet been signaled. + */ + new = atomic_read(&fence->pending); + do { + if (new < 1) + return false; + + old = new++; + } while ((new = atomic_cmpxchg(&fence->pending, old, new)) != old); + + return true; } void __i915_sw_fence_init(struct i915_sw_fence *fence, diff --git a/drivers/gpu/drm/i915/i915_sw_fence.h b/drivers/gpu/drm/i915/i915_sw_fence.h index 19e806ce43bc..30a863353ee6 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence.h +++ b/drivers/gpu/drm/i915/i915_sw_fence.h @@ -91,7 +91,7 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence, unsigned long timeout, gfp_t gfp); -void i915_sw_fence_await(struct i915_sw_fence *fence); +bool i915_sw_fence_await(struct i915_sw_fence *fence); void i915_sw_fence_complete(struct i915_sw_fence *fence); static inline bool i915_sw_fence_signaled(const struct i915_sw_fence *fence) -- 2.25.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx