From patchwork Fri Apr 24 16:26:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kenny Levinsen X-Patchwork-Id: 11509029 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B49C792A for ; Fri, 24 Apr 2020 20:08:02 +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 939AB20857 for ; Fri, 24 Apr 2020 20:08:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kl.wtf header.i=@kl.wtf header.b="EM1KJp2T" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 939AB20857 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kl.wtf Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 091186EB13; Fri, 24 Apr 2020 20:08:00 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org X-Greylist: delayed 5684 seconds by postgrey-1.36 at gabe; Fri, 24 Apr 2020 16:26:27 UTC Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by gabe.freedesktop.org (Postfix) with ESMTPS id 85E6389F41; Fri, 24 Apr 2020 16:26:27 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kl.wtf; s=default; t=1587745584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=8mdi2DQZnKTxhiyh5ltJlv4SJnThbSF3Vb3HnH3+DYU=; b=EM1KJp2Tn3uJ4k4JmB8agIjC8AO5zxy2CWr3tlHRh/VeOutwbf6EbybYXiabug4NXaOv77 BmPHjcchgF4NBvEy2nDq6iOpOQA/vS1egSLhZXHyZZ2Uy+ybaxnW5ShJJuD9anR0B///Dv 21x+3Ntcfp+3U0c6XL8z8yAnOuuNeJ0= From: Kenny Levinsen To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH v2] drm: make drm_file use keyed wakeups Date: Fri, 24 Apr 2020 18:26:15 +0200 Message-Id: <20200424162615.10461-1-kl@kl.wtf> MIME-Version: 1.0 X-Spam-Score: 4.90 X-Mailman-Approved-At: Fri, 24 Apr 2020 20:07:59 +0000 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: , Cc: airlied@linux.ie, linux-kernel@vger.kernel.org, Kenny Levinsen , tzimmermann@suse.de Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Some processes, such as systemd, are only polling for EPOLLERR|EPOLLHUP. As drm_file uses unkeyed wakeups, such a poll can receive many spurious wakeups from uninteresting events if, for example, the file description is subscribed to vblank events. This is the case with systemd, as it polls a file description from logind that is shared with the users' compositor. Use keyed wakeups to allow the wakeup target to more efficiently discard these uninteresting events. Signed-off-by: Kenny Levinsen --- drivers/gpu/drm/drm_file.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index c4c704e01961..ec25b3d979d9 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -608,7 +608,8 @@ ssize_t drm_read(struct file *filp, char __user *buffer, file_priv->event_space -= length; list_add(&e->link, &file_priv->event_list); spin_unlock_irq(&dev->event_lock); - wake_up_interruptible(&file_priv->event_wait); + wake_up_interruptible_poll(&file_priv->event_wait, + EPOLLIN | EPOLLRDNORM); break; } @@ -804,7 +805,8 @@ void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e) list_del(&e->pending_link); list_add_tail(&e->link, &e->file_priv->event_list); - wake_up_interruptible(&e->file_priv->event_wait); + wake_up_interruptible_poll(&e->file_priv->event_wait, + EPOLLIN | EPOLLRDNORM); } EXPORT_SYMBOL(drm_send_event_locked);