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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 6FF34C10F1A for ; Wed, 1 May 2024 16:31:01 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4C9EE1123AF; Wed, 1 May 2024 16:31:00 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; secure) header.d=ffwll.ch header.i=@ffwll.ch header.b="LZkRZY4P"; dkim-atps=neutral Received: from mail-lj1-f178.google.com (mail-lj1-f178.google.com [209.85.208.178]) by gabe.freedesktop.org (Postfix) with ESMTPS id A0706112305 for ; Wed, 1 May 2024 16:30:58 +0000 (UTC) Received: by mail-lj1-f178.google.com with SMTP id 38308e7fff4ca-2dcae31018aso1279791fa.0 for ; Wed, 01 May 2024 09:30:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; t=1714581057; x=1715185857; darn=lists.freedesktop.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:mail-followup-to:message-id:subject:cc:to :from:date:from:to:cc:subject:date:message-id:reply-to; bh=y752jhftptdt0C7UFaUbMxDQZl9ZN6d8fmcUcY8z3mk=; b=LZkRZY4Pi+yNyew+sJ8/5kLbd2iL3/M2huuMWWucIEIfU2sKYgDWvonREtZ3Gs+kdF ZiVwE8pRlqyhJpgl3sXTsTNzOBOQt1oWUnplUHeTyvfRzUXBD0cs+SFBNRu5tKjPBatl 6aa1H5UaZvMmNNlkv3lLlVuAiJNkdm7beZ8bo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714581057; x=1715185857; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:mail-followup-to:message-id:subject:cc:to :from:date:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=y752jhftptdt0C7UFaUbMxDQZl9ZN6d8fmcUcY8z3mk=; b=uqeA+DYmpZqwn+4HaaukeV/mUvASILSClUZTQWyiaL98W1mayHC+bwyRsr0osH3bco LYvNfrGU0Yh6YpRm5DlleUXLHizvZbPPbXuD/1NGrDrfGvfS6DFJQnm7OIEd6u+52Kj9 c8c0qdpFAVBoXEiPX2srSobE0d3uKYPukCrr4qmVLmuR8BKY2pCxfhKMshWnyc5i/cKV ++wEdRlx4sPpoBTKMRtcupJeZpyFEKP8sHd5Dq7yQmVVrFyNzlWB46PN2QsR0kGcUU4s hMxS33MamCi7RjOa88pkbV1uheLV19xWOFRHKx9Y/54IT1CAGmniFGseaK/EdCM7AYP8 9tIA== X-Forwarded-Encrypted: i=1; AJvYcCVCMW9fbi6Yqy7exhqohabNd6YWVAk5jjd5sLbLVOj4CGIC0k8RPh/xtL/HNhAosK8uc87wb7BJkzzZhx+IovQ3LBSdjgcgOUUQdZIq60F/ X-Gm-Message-State: AOJu0Yy23ivHBNn0HHQLYPs8jhC0Cnfco0m5RtpG+IH1ht2dUc1FSrTl mjx/J9iRGVA7c/ucbq+zzUByYCercCXMW6foN3PIKzFGbiyLumpRu5G7T3CoboE= X-Google-Smtp-Source: AGHT+IGOJ9H+Nbtt2+OO9+GYWkWMUBLFGQppNYe+EIrQMMqtvnGDY+i0r0rEj2BJ6xY09jE/PuJLbw== X-Received: by 2002:a2e:9e15:0:b0:2df:4a6a:a18d with SMTP id e21-20020a2e9e15000000b002df4a6aa18dmr1821945ljk.2.1714581056513; Wed, 01 May 2024 09:30:56 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id o27-20020a05600c511b00b00418a386c17bsm2665811wms.12.2024.05.01.09.30.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 May 2024 09:30:55 -0700 (PDT) Date: Wed, 1 May 2024 18:30:53 +0200 From: Daniel Vetter To: =?iso-8859-1?Q?Adri=E1n?= Larumbe Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Hans de Goede , kernel@collabora.com, Boris Brezillon , Tvrtko Ursulin , Christopher Healy , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/sysfs: Add drm class-wide attribute to get active device clients Message-ID: Mail-Followup-To: =?iso-8859-1?Q?Adri=E1n?= Larumbe , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Hans de Goede , kernel@collabora.com, Boris Brezillon , Tvrtko Ursulin , Christopher Healy , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20240403182951.724488-1-adrian.larumbe@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240403182951.724488-1-adrian.larumbe@collabora.com> X-Operating-System: Linux phenom 6.6.15-amd64 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Apr 03, 2024 at 07:29:39PM +0100, Adrián Larumbe wrote: > Up to this day, all fdinfo-based GPU profilers must traverse the entire > /proc directory structure to find open DRM clients with fdinfo file > descriptors. This is inefficient and time-consuming. > > This patch adds a new device class attribute that will install a sysfs file > per DRM device, which can be queried by profilers to get a list of PIDs for > their open clients. This file isn't human-readable, and it's meant to be > queried only by GPU profilers like gputop and nvtop. > > Cc: Boris Brezillon > Cc: Tvrtko Ursulin > Cc: Christopher Healy > Signed-off-by: Adrián Larumbe Tvrtko pointed me at this on irc and .. uh I think this definitely needs an ack from Greg KH before we can land it. It's quite far away from what sysfs uapi usually looks like and also semantically does ... -Sima > --- > drivers/gpu/drm/drm_internal.h | 2 +- > drivers/gpu/drm/drm_privacy_screen.c | 2 +- > drivers/gpu/drm/drm_sysfs.c | 89 ++++++++++++++++++++++------ > 3 files changed, 74 insertions(+), 19 deletions(-) > > diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h > index 2215baef9a3e..9a399b03d11c 100644 > --- a/drivers/gpu/drm/drm_internal.h > +++ b/drivers/gpu/drm/drm_internal.h > @@ -145,7 +145,7 @@ bool drm_master_internal_acquire(struct drm_device *dev); > void drm_master_internal_release(struct drm_device *dev); > > /* drm_sysfs.c */ > -extern struct class *drm_class; > +extern struct class drm_class; > > int drm_sysfs_init(void); > void drm_sysfs_destroy(void); > diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c > index 6cc39e30781f..2fbd24ba5818 100644 > --- a/drivers/gpu/drm/drm_privacy_screen.c > +++ b/drivers/gpu/drm/drm_privacy_screen.c > @@ -401,7 +401,7 @@ struct drm_privacy_screen *drm_privacy_screen_register( > mutex_init(&priv->lock); > BLOCKING_INIT_NOTIFIER_HEAD(&priv->notifier_head); > > - priv->dev.class = drm_class; > + priv->dev.class = &drm_class; > priv->dev.type = &drm_privacy_screen_type; > priv->dev.parent = parent; > priv->dev.release = drm_privacy_screen_device_release; > diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c > index a953f69a34b6..56ca9e22c720 100644 > --- a/drivers/gpu/drm/drm_sysfs.c > +++ b/drivers/gpu/drm/drm_sysfs.c > @@ -58,8 +58,6 @@ static struct device_type drm_sysfs_device_connector = { > .name = "drm_connector", > }; > > -struct class *drm_class; > - > #ifdef CONFIG_ACPI > static bool drm_connector_acpi_bus_match(struct device *dev) > { > @@ -128,6 +126,62 @@ static const struct component_ops typec_connector_ops = { > > static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810"); > > +static ssize_t clients_show(struct device *cd, struct device_attribute *attr, char *buf) > +{ > + struct drm_minor *minor = cd->driver_data; > + struct drm_device *ddev = minor->dev; > + struct drm_file *priv; > + ssize_t offset = 0; > + void *pid_buf; > + > + if (minor->type != DRM_MINOR_RENDER) > + return 0; > + > + pid_buf = kvmalloc(PAGE_SIZE, GFP_KERNEL); > + if (!pid_buf) > + return 0; > + > + mutex_lock(&ddev->filelist_mutex); > + list_for_each_entry_reverse(priv, &ddev->filelist, lhead) { > + struct pid *pid; > + > + if (drm_WARN_ON(ddev, (PAGE_SIZE - offset) < sizeof(pid_t))) > + break; > + > + rcu_read_lock(); > + pid = rcu_dereference(priv->pid); > + (*(pid_t *)(pid_buf + offset)) = pid_vnr(pid); > + rcu_read_unlock(); > + > + offset += sizeof(pid_t); > + } > + mutex_unlock(&ddev->filelist_mutex); > + > + if (offset < PAGE_SIZE) > + (*(pid_t *)(pid_buf + offset)) = 0; > + > + memcpy(buf, pid_buf, offset); > + > + kvfree(pid_buf); > + > + return offset; > + > +} > +static DEVICE_ATTR_RO(clients); > + > +static struct attribute *drm_device_attrs[] = { > + &dev_attr_clients.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(drm_device); > + > +struct class drm_class = { > + .name = "drm", > + .dev_groups = drm_device_groups, > +}; > + > +static bool drm_class_initialised; > + > /** > * drm_sysfs_init - initialize sysfs helpers > * > @@ -142,18 +196,19 @@ int drm_sysfs_init(void) > { > int err; > > - drm_class = class_create("drm"); > - if (IS_ERR(drm_class)) > - return PTR_ERR(drm_class); > + err = class_register(&drm_class); > + if (err) > + return err; > > - err = class_create_file(drm_class, &class_attr_version.attr); > + err = class_create_file(&drm_class, &class_attr_version.attr); > if (err) { > - class_destroy(drm_class); > - drm_class = NULL; > + class_destroy(&drm_class); > return err; > } > > - drm_class->devnode = drm_devnode; > + drm_class.devnode = drm_devnode; > + > + drm_class_initialised = true; > > drm_sysfs_acpi_register(); > return 0; > @@ -166,12 +221,12 @@ int drm_sysfs_init(void) > */ > void drm_sysfs_destroy(void) > { > - if (IS_ERR_OR_NULL(drm_class)) > + if (!drm_class_initialised) > return; > drm_sysfs_acpi_unregister(); > - class_remove_file(drm_class, &class_attr_version.attr); > - class_destroy(drm_class); > - drm_class = NULL; > + class_remove_file(&drm_class, &class_attr_version.attr); > + class_destroy(&drm_class); > + drm_class_initialised = false; > } > > static void drm_sysfs_release(struct device *dev) > @@ -372,7 +427,7 @@ int drm_sysfs_connector_add(struct drm_connector *connector) > return -ENOMEM; > > device_initialize(kdev); > - kdev->class = drm_class; > + kdev->class = &drm_class; > kdev->type = &drm_sysfs_device_connector; > kdev->parent = dev->primary->kdev; > kdev->groups = connector_dev_groups; > @@ -550,7 +605,7 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor) > minor_str = "card%d"; > > kdev->devt = MKDEV(DRM_MAJOR, minor->index); > - kdev->class = drm_class; > + kdev->class = &drm_class; > kdev->type = &drm_sysfs_device_minor; > } > > @@ -579,10 +634,10 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor) > */ > int drm_class_device_register(struct device *dev) > { > - if (!drm_class || IS_ERR(drm_class)) > + if (!drm_class_initialised) > return -ENOENT; > > - dev->class = drm_class; > + dev->class = &drm_class; > return device_register(dev); > } > EXPORT_SYMBOL_GPL(drm_class_device_register); > > base-commit: 45c734fdd43db14444025910b4c59dd2b8be714a > -- > 2.44.0 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch