From patchwork Thu Aug 4 19:52:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 9264229 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C7F7060839 for ; Thu, 4 Aug 2016 19:53:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BA2FE2841C for ; Thu, 4 Aug 2016 19:53:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AEC9728425; Thu, 4 Aug 2016 19:53:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F02E2841C for ; Thu, 4 Aug 2016 19:53:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C5DD56EA4C; Thu, 4 Aug 2016 19:53:18 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-wm0-x242.google.com (mail-wm0-x242.google.com [IPv6:2a00:1450:400c:c09::242]) by gabe.freedesktop.org (Postfix) with ESMTPS id A1A866EA45 for ; Thu, 4 Aug 2016 19:52:59 +0000 (UTC) Received: by mail-wm0-x242.google.com with SMTP id o80so708432wme.0 for ; Thu, 04 Aug 2016 12:52:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=5aD5hcApPnJX2KGaj3Wa5O7+lTc3nvEbdy4zjwjp3EA=; b=t4BFayYwfaXPEyxKVCjF5UsfT4DlLq9N5X/ZnPVDyAN+DYVW1/JexgM6dHKb6KJQOL +6KKgd8K9/QLapC2SVeHkiwLd34PJTP36WV5qaeU1hYZnAyyRrKRqK1GE5sxlOwmTp98 jyw9gHLEeE8e+2BCPDswGXOcP6itdAEb9BZ+ZicqonMaVmctkmM9LHgjdLBfTp87p++o R2PG91vASaXfHaLpbnWXEE9kQmSEjJwMReCWoJUpXQHE36PmSw31UloMo6D09Ux4C0KT L2RiDyCUjI6hzwlWGkaoXQIZRAXX+zn5yHhNpdbifWDHeeua2w3YizQsvFDVrpSS/hDk pkmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=5aD5hcApPnJX2KGaj3Wa5O7+lTc3nvEbdy4zjwjp3EA=; b=DKZUxeIZUqzVafnMrZl2Ns8oOb6PEyu48IZQVfo+qGBgdOCi9gFv1AvVJVp9aCtp5g MaPWFsjidoaBNyWYhq5YWEFXA9klY4dZ6dda7dn5qaZguBzsT/JzI2vimLwmeIy6CFxr sybFoierVxa2AKTV+vIWlpe8A8ygZRAQnMFpzqvdYBmlkMN41WwNiNqObzaR75Oq83I8 RunItIF1K88t259VD6gWtpOupAF7lf76sm01U4O53pc0FEuXebUDhm7iC5WeiTt1OWv8 Ewwsbbuq18aHqvxI7hqDoILwUPsyOlYhqzdy+HrfjULx23UtoiYl/PFIyYo4jNIyljaa X8Tg== X-Gm-Message-State: AEkoouu0LNI51Bu3CS6WzQFTFsg23qiSbcMvmtz+2TCO8qmzoicdFu30PDNnAwWzNWEXKQ== X-Received: by 10.28.225.4 with SMTP id y4mr74976381wmg.98.1470340376271; Thu, 04 Aug 2016 12:52:56 -0700 (PDT) Received: from haswell.alporthouse.com ([78.156.65.138]) by smtp.gmail.com with ESMTPSA id i3sm14301931wjd.31.2016.08.04.12.52.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Aug 2016 12:52:55 -0700 (PDT) From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Thu, 4 Aug 2016 20:52:27 +0100 Message-Id: <1470340352-16118-15-git-send-email-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1470340352-16118-1-git-send-email-chris@chris-wilson.co.uk> References: <1470340352-16118-1-git-send-email-chris@chris-wilson.co.uk> Cc: Daniel Vetter Subject: [Intel-gfx] [PATCH 14/19] drm/i915: Reduce locking inside swfinish ioctl X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP We only need to take the struct_mutex if the object is pinned to the display engine and so requires checking for clflush. (The race with userspace pinning the object to a framebuffer is irrelevant.) v2: Use access once for compiler hints (or not as it is a bitfield) v3: READ_ONCE, obj->pin_display is not a bitfield anymore v4: Don't be creative with goto. Signed-off-by: Chris Wilson Cc: Daniel Vetter Reviewed-by: Joonas Lahtinen --- drivers/gpu/drm/i915/i915_gem.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 5ec3ebf33bc8..e18e30dfac4d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1516,26 +1516,23 @@ i915_gem_sw_finish_ioctl(struct drm_device *dev, void *data, { struct drm_i915_gem_sw_finish *args = data; struct drm_i915_gem_object *obj; - int ret = 0; - - ret = i915_mutex_lock_interruptible(dev); - if (ret) - return ret; + int err = 0; obj = i915_gem_object_lookup(file, args->handle); - if (!obj) { - ret = -ENOENT; - goto unlock; - } + if (!obj) + return -ENOENT; /* Pinned buffers may be scanout, so flush the cache */ - if (obj->pin_display) - i915_gem_object_flush_cpu_write_domain(obj); + if (READ_ONCE(obj->pin_display)) { + err = i915_mutex_lock_interruptible(dev); + if (!err) { + i915_gem_object_flush_cpu_write_domain(obj); + mutex_unlock(&dev->struct_mutex); + } + } - i915_gem_object_put(obj); -unlock: - mutex_unlock(&dev->struct_mutex); - return ret; + i915_gem_object_put_unlocked(obj); + return err; } /**