From patchwork Sat Aug 14 10:43:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 12436635 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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 D4C33C4338F for ; Sat, 14 Aug 2021 10:43:30 +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 D421160F36 for ; Sat, 14 Aug 2021 10:43:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D421160F36 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 20BA56E7F1; Sat, 14 Aug 2021 10:43:28 +0000 (UTC) Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by gabe.freedesktop.org (Postfix) with ESMTPS id 495AA6E822 for ; Sat, 14 Aug 2021 10:43:27 +0000 (UTC) Received: by mail-wm1-x330.google.com with SMTP id u1so8483467wmm.0 for ; Sat, 14 Aug 2021 03:43:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=CyDGn+m3A62QU/f5ahs1P8PN0sPNitsk0uBwhLraIGg=; b=hoz1sOfO1U7isCTJyaYB3tv91GogfJw9C+h8KcBCGPm1Pn2xVtB6MitpDsKLoyuyBR tUqn0kSdZYKKynL9CljP0jFMjA3WyKn2idRu3oixv+98446LpOLYT6bPm/k4lDjFl3PK O/hciPvMPM1jScpR1qprvZ2TfUpicD9d5DOSE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CyDGn+m3A62QU/f5ahs1P8PN0sPNitsk0uBwhLraIGg=; b=qzYX9IokyL9ZvpAcFkgFFEB3xWMPp7tLOWDTW3DxYKVDU32tSPkPt5OasfoM4/05GY QuWrvrEyQ8oucnDQsmtQMqZBw1Z1jeFlZtabbQ095jddQmFZIF9A5/xLjUUcBDuOs9pv dnxV60E2p1sHVtDuHM+wRYJmvsXNtC/YiRj91DYqIv+AcSwPH2y2ntjL4e4H5s0IhMW9 7ZumXpqB/If60O96172gx957cEWIahDP0emH59ixIvvodbSgtJxSQcvwvVN/Bv4qQ8OK L3/iYtzQ7Eav+/em341G5FY0dpfyFSE8FtKIcoNgijJLc8FOe4yeU+vjZcwJadUjetXo spDA== X-Gm-Message-State: AOAM532PhUk2eORyLlmgb5w5tW96CbEztcaioEdEnfa+lrXyvGyJk1wT cAbaxVd/IomKJfADXH+lm9m+b1IEaWkaSw== X-Google-Smtp-Source: ABdhPJxbmml8chvHH/JLOwxQOSBIIrJ5F8p83MufDVLxuwWlvWOdwfqO3g/rQY9w+Pzr6/kQNSAhrg== X-Received: by 2002:a7b:cde8:: with SMTP id p8mr6471984wmj.119.1628937805523; Sat, 14 Aug 2021 03:43:25 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id t8sm4995434wrx.27.2021.08.14.03.43.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Aug 2021 03:43:24 -0700 (PDT) From: Daniel Vetter To: Intel Graphics Development Cc: DRI Development , Daniel Vetter , Daniel Vetter , Jon Bloomfield , Chris Wilson , Maarten Lankhorst , Joonas Lahtinen , =?utf-8?q?Thomas_Hellstr?= =?utf-8?q?=C3=B6m?= , Matthew Auld , Lionel Landwerlin , Dave Airlie , Jason Ekstrand Date: Sat, 14 Aug 2021 12:43:19 +0200 Message-Id: <20210814104319.3226156-1-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210813203033.3179400-1-daniel.vetter@ffwll.ch> References: <20210813203033.3179400-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915: Release i915_gem_context from a worker 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" The only reason for this really is the i915_gem_engines->fence callback engines_notify(), which exists purely as a fairly funky reference counting scheme for that. Otherwise all other callers are from process context, and generally fairly benign locking context. Unfortunately untangling that requires some major surgery, and we have a few i915_gem_context reference counting bugs that need fixing, and they blow in the current hardirq calling context, so we need a stop-gap measure. Put a FIXME comment in when this should be removable again. v2: Fix mock_context(), noticed by intel-gfx-ci. Signed-off-by: Daniel Vetter Cc: Jon Bloomfield Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Joonas Lahtinen Cc: Daniel Vetter Cc: "Thomas Hellström" Cc: Matthew Auld Cc: Lionel Landwerlin Cc: Dave Airlie Cc: Jason Ekstrand --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 13 +++++++++++-- drivers/gpu/drm/i915/gem/i915_gem_context_types.h | 12 ++++++++++++ drivers/gpu/drm/i915/gem/selftests/mock_context.c | 1 + 3 files changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index fd169cf2f75a..051bc357ff65 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -986,9 +986,10 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx, return err; } -void i915_gem_context_release(struct kref *ref) +static void i915_gem_context_release_work(struct work_struct *work) { - struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref); + struct i915_gem_context *ctx = container_of(work, typeof(*ctx), + release_work); trace_i915_context_free(ctx); GEM_BUG_ON(!i915_gem_context_is_closed(ctx)); @@ -1002,6 +1003,13 @@ void i915_gem_context_release(struct kref *ref) kfree_rcu(ctx, rcu); } +void i915_gem_context_release(struct kref *ref) +{ + struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref); + + queue_work(ctx->i915->wq, &ctx->release_work); +} + static inline struct i915_gem_engines * __context_engines_static(const struct i915_gem_context *ctx) { @@ -1303,6 +1311,7 @@ i915_gem_create_context(struct drm_i915_private *i915, ctx->sched = pc->sched; mutex_init(&ctx->mutex); INIT_LIST_HEAD(&ctx->link); + INIT_WORK(&ctx->release_work, i915_gem_context_release_work); spin_lock_init(&ctx->stale.lock); INIT_LIST_HEAD(&ctx->stale.engines); 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 94c03a97cb77..0c38789bd4a8 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h @@ -288,6 +288,18 @@ struct i915_gem_context { */ struct kref ref; + /** + * @release_work: + * + * Work item for deferred cleanup, since i915_gem_context_put() tends to + * be called from hardirq context. + * + * FIXME: The only real reason for this is &i915_gem_engines.fence, all + * other callers are from process context and need at most some mild + * shuffling to pull the i915_gem_context_put() call out of a spinlock. + */ + struct work_struct release_work; + /** * @rcu: rcu_head for deferred freeing. */ diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_context.c b/drivers/gpu/drm/i915/gem/selftests/mock_context.c index fee070df1c97..067d68a6fe4c 100644 --- a/drivers/gpu/drm/i915/gem/selftests/mock_context.c +++ b/drivers/gpu/drm/i915/gem/selftests/mock_context.c @@ -23,6 +23,7 @@ mock_context(struct drm_i915_private *i915, kref_init(&ctx->ref); INIT_LIST_HEAD(&ctx->link); ctx->i915 = i915; + INIT_WORK(&ctx->release_work, i915_gem_context_release_work); mutex_init(&ctx->mutex);