From nobody Mon Sep 15 11:53:48 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 752A1C61DB3 for ; Thu, 12 Jan 2023 17:37:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229483AbjALRhG (ORCPT ); Thu, 12 Jan 2023 12:37:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54508 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232449AbjALRgN (ORCPT ); Thu, 12 Jan 2023 12:36:13 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30E8FCA268; Thu, 12 Jan 2023 08:57:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1673542675; x=1705078675; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=LFWfaBaBSYjaapQ05IsoDGjzc+hjHAEDqfXfuRz8U04=; b=koY1NszC6Xx0lSaW+SSnGuUt/W/IiW2A1SAcCFT4rwDUZoWUqYk0gEWB RfRL/M4S2S/PKXmjCxQO+ZQjb4P0nmLKl7vpHfmO//2TAVx358gCp4GID b64aVdOfj16vKssbNrinIjorKpfQyVwmsmHmIApnCHxmiWq2ETJRLI5+z sbQRcEG3boT5Ia5IFAlBLJmA5A+r5gsI5s9mDtmfji+RCOjdYHcUOK+0a DfdaksDjDp0qNbsKFncZtmP9adlP9PBQBSwJw8NDkNmiy1LoIRIfcyMGT /0co6a15XoX9mGmdNuyNbef2DyYyyyq/w6NzIH8AFA7a6Oju1D9L1jrfh A==; X-IronPort-AV: E=McAfee;i="6500,9779,10588"; a="325016400" X-IronPort-AV: E=Sophos;i="5.97,211,1669104000"; d="scan'208";a="325016400" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 08:56:42 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10588"; a="651232669" X-IronPort-AV: E=Sophos;i="5.97,211,1669104000"; d="scan'208";a="651232669" Received: from jacton-mobl.ger.corp.intel.com (HELO localhost.localdomain) ([10.213.195.171]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 08:56:38 -0800 From: Tvrtko Ursulin To: Intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Tejun Heo , Johannes Weiner , Zefan Li , Dave Airlie , Daniel Vetter , Rob Clark , =?UTF-8?q?St=C3=A9phane=20Marchesin?= , "T . J . Mercier" , Kenny.Ho@amd.com, =?UTF-8?q?Christian=20K=C3=B6nig?= , Brian Welty , Tvrtko Ursulin Subject: [RFC 04/12] drm/cgroup: Track clients per owning process Date: Thu, 12 Jan 2023 16:56:01 +0000 Message-Id: <20230112165609.1083270-5-tvrtko.ursulin@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230112165609.1083270-1-tvrtko.ursulin@linux.intel.com> References: <20230112165609.1083270-1-tvrtko.ursulin@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tvrtko Ursulin To enable propagation of settings from the cgroup drm controller to drm we need to start tracking which processes own which drm clients. Implement that by tracking the struct pid pointer of the owning process in a new XArray, pointing to a structure containing a list of associated struct drm_file pointers. Clients are added and removed under the filelist mutex and RCU list operations are used below it to allow for lockless lookup. Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_cgroup.c | 133 +++++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_file.c | 20 ++++-- include/drm/drm_clients.h | 44 ++++++++++++ include/drm/drm_file.h | 4 ++ 5 files changed, 198 insertions(+), 4 deletions(-) create mode 100644 drivers/gpu/drm/drm_cgroup.c create mode 100644 include/drm/drm_clients.h diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 496fa5a6147a..c036b1b379c4 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -59,6 +59,7 @@ drm-$(CONFIG_DRM_LEGACY) +=3D \ drm_scatter.o \ drm_vm.o drm-$(CONFIG_DRM_LIB_RANDOM) +=3D lib/drm_random.o +drm-$(CONFIG_CGROUP_DRM) +=3D drm_cgroup.o drm-$(CONFIG_COMPAT) +=3D drm_ioc32.o drm-$(CONFIG_DRM_PANEL) +=3D drm_panel.o drm-$(CONFIG_OF) +=3D drm_of.o diff --git a/drivers/gpu/drm/drm_cgroup.c b/drivers/gpu/drm/drm_cgroup.c new file mode 100644 index 000000000000..d91512a560ff --- /dev/null +++ b/drivers/gpu/drm/drm_cgroup.c @@ -0,0 +1,133 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright =C2=A9 2022 Intel Corporation + */ + +#include +#include +#include + +static DEFINE_XARRAY(drm_pid_clients); + +static void +__del_clients(struct drm_pid_clients *clients, + struct drm_file *file_priv, + unsigned long pid) +{ + list_del_rcu(&file_priv->clink); + if (atomic_dec_and_test(&clients->num)) { + xa_erase(&drm_pid_clients, pid); + kfree_rcu(clients, rcu); + } +} + +void drm_clients_close(struct drm_file *file_priv) +{ + struct drm_device *dev =3D file_priv->minor->dev; + struct drm_pid_clients *clients; + struct pid *pid; + + lockdep_assert_held(&dev->filelist_mutex); + + pid =3D rcu_access_pointer(file_priv->pid); + clients =3D xa_load(&drm_pid_clients, (unsigned long)pid); + if (drm_WARN_ON_ONCE(dev, !clients)) + return; + + __del_clients(clients, file_priv, (unsigned long)pid); +} + +static struct drm_pid_clients *__alloc_clients(void) +{ + struct drm_pid_clients *clients; + + clients =3D kmalloc(sizeof(*clients), GFP_KERNEL); + if (clients) { + atomic_set(&clients->num, 0); + INIT_LIST_HEAD(&clients->file_list); + init_rcu_head(&clients->rcu); + } + + return clients; +} + +int drm_clients_open(struct drm_file *file_priv) +{ + struct drm_device *dev =3D file_priv->minor->dev; + struct drm_pid_clients *clients; + bool new_client =3D false; + unsigned long pid; + + lockdep_assert_held(&dev->filelist_mutex); + + pid =3D (unsigned long)rcu_access_pointer(file_priv->pid); + clients =3D xa_load(&drm_pid_clients, pid); + if (!clients) { + clients =3D __alloc_clients(); + if (!clients) + return -ENOMEM; + new_client =3D true; + } + atomic_inc(&clients->num); + list_add_tail_rcu(&file_priv->clink, &clients->file_list); + if (new_client) { + void *xret; + + xret =3D xa_store(&drm_pid_clients, pid, clients, GFP_KERNEL); + if (xa_err(xret)) { + list_del_init(&file_priv->clink); + kfree(clients); + return PTR_ERR(clients); + } + } + + return 0; +} + +void +drm_clients_migrate(struct drm_file *file_priv, + struct pid *old, + struct pid *new) +{ + struct drm_device *dev =3D file_priv->minor->dev; + struct drm_pid_clients *existing_clients; + struct drm_pid_clients *clients; + + lockdep_assert_held(&dev->filelist_mutex); + + existing_clients =3D xa_load(&drm_pid_clients, (unsigned long)new); + clients =3D xa_load(&drm_pid_clients, (unsigned long)old); + + if (drm_WARN_ON_ONCE(dev, !clients)) + return; + else if (drm_WARN_ON_ONCE(dev, clients =3D=3D existing_clients)) + return; + + __del_clients(clients, file_priv, (unsigned long)old); + + if (!existing_clients) { + void *xret; + + clients =3D __alloc_clients(); + if (!clients) + goto err; + + xret =3D xa_store(&drm_pid_clients, (unsigned long)new, clients, + GFP_KERNEL); + if (xa_err(xret)) + goto err; + } else { + clients =3D existing_clients; + } + + atomic_inc(&clients->num); + list_add_tail_rcu(&file_priv->clink, &clients->file_list); + + return; + +err: + rcu_read_lock(); + drm_warn(dev, "Failed to migrate client from pid %u to %u!\n", + pid_nr(old), pid_nr(new)); + rcu_read_unlock(); +} diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index f2f8175ece15..5cf446f721f8 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -40,6 +40,7 @@ #include =20 #include +#include #include #include #include @@ -298,6 +299,7 @@ static void drm_close_helper(struct file *filp) =20 mutex_lock(&dev->filelist_mutex); list_del(&file_priv->lhead); + drm_clients_close(file_priv); mutex_unlock(&dev->filelist_mutex); =20 drm_file_free(file_priv); @@ -349,10 +351,8 @@ int drm_open_helper(struct file *filp, struct drm_mino= r *minor) =20 if (drm_is_primary_client(priv)) { ret =3D drm_master_open(priv); - if (ret) { - drm_file_free(priv); - return ret; - } + if (ret) + goto err_free; } =20 filp->private_data =3D priv; @@ -360,6 +360,9 @@ int drm_open_helper(struct file *filp, struct drm_minor= *minor) priv->filp =3D filp; =20 mutex_lock(&dev->filelist_mutex); + ret =3D drm_clients_open(priv); + if (ret) + goto err_unlock; list_add(&priv->lhead, &dev->filelist); mutex_unlock(&dev->filelist_mutex); =20 @@ -387,6 +390,13 @@ int drm_open_helper(struct file *filp, struct drm_mino= r *minor) #endif =20 return 0; + +err_unlock: + mutex_unlock(&dev->filelist_mutex); +err_free: + drm_file_free(priv); + + return ret; } =20 /** @@ -526,6 +536,8 @@ void drm_file_update_pid(struct drm_file *filp) dev =3D filp->minor->dev; mutex_lock(&dev->filelist_mutex); old =3D rcu_replace_pointer(filp->pid, pid, 1); + if (pid !=3D old) + drm_clients_migrate(filp, old, pid); mutex_unlock(&dev->filelist_mutex); =20 if (pid !=3D old) { diff --git a/include/drm/drm_clients.h b/include/drm/drm_clients.h new file mode 100644 index 000000000000..2732fffab3f0 --- /dev/null +++ b/include/drm/drm_clients.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright =C2=A9 2022 Intel Corporation + */ + +#ifndef _DRM_CLIENTS_H_ +#define _DRM_CLIENTS_H_ + +#include + +#include + +struct drm_pid_clients { + atomic_t num; + struct list_head file_list; + struct rcu_head rcu; +}; + +#if IS_ENABLED(CONFIG_CGROUP_DRM) +void drm_clients_close(struct drm_file *file_priv); +int drm_clients_open(struct drm_file *file_priv); + +void +drm_clients_migrate(struct drm_file *file_priv, + struct pid *old, struct pid *new); +#else +static inline void drm_clients_close(struct drm_file *file_priv) +{ +} + +static inline int drm_clients_open(struct drm_file *file_priv) +{ + return 0; +} + +static void +drm_clients_migrate(struct drm_file *file_priv, + struct pid *old, struct pid *new) +{ + +} +#endif + +#endif diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h index 27d545131d4a..644c5b17d6a7 100644 --- a/include/drm/drm_file.h +++ b/include/drm/drm_file.h @@ -279,6 +279,10 @@ struct drm_file { /** @minor: &struct drm_minor for this file. */ struct drm_minor *minor; =20 +#if IS_ENABLED(CONFIG_CGROUP_DRM) + struct list_head clink; +#endif + /** * @object_idr: * --=20 2.34.1