From patchwork Tue Oct 26 11:40:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 12584691 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACDFCC433EF for ; Tue, 26 Oct 2021 11:41:41 +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 830ED60C4B for ; Tue, 26 Oct 2021 11:41:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 830ED60C4B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de 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 B85036E833; Tue, 26 Oct 2021 11:41:13 +0000 (UTC) Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id 05B936E5A4; Tue, 26 Oct 2021 11:41:08 +0000 (UTC) From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1635248467; 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: in-reply-to:in-reply-to:references:references; bh=16LhI+4TK6S3ciJa1zXFgSSoRr47T7KSWkrj5hZ8Xv4=; b=xY0vT4oX9+I02HcPeO3vpxNvalYG+rYh+7HUF+p7c424m+6mPLSXvQs16qhFLMZ80HSGaq fC1mBrBjsQ9JnYTN71Utspu0JIw2KJ32Doz8dLOdFKSrIDrQAgEgeXq0tGm+2d/Q0p4i7u YbHuBf1tqd/fYGWYyyCyAxYFCe3yLyFEQ/vO6E/NpowiTAj9yloIeZPNCYehI1xpSNDCWj n7S7J+zojzU0jcqRbL1g1ar1h8A1X74OzvXW73nBv9uqEyEHsUZsoD8bvS8/Dwpo0aQXnF B1ex/g8D/bpeJvDbbPhjbyq3swfELvuusu6n/K0enUMMC0FOtvvLZW0l6zopEg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1635248467; 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: in-reply-to:in-reply-to:references:references; bh=16LhI+4TK6S3ciJa1zXFgSSoRr47T7KSWkrj5hZ8Xv4=; b=R6RBOHFHD5OMxLBU4KxK9ocjzGzGYr+85zREXZtFcV3i9ulBOCss/7KG33eq8+/9wf30PY 27xYGVRz0cVTnCDg== To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , Thomas Gleixner , Peter Zijlstra , Sebastian Andrzej Siewior Subject: [PATCH 7/9] drm/i915: Don't check for atomic context on PREEMPT_RT Date: Tue, 26 Oct 2021 13:40:58 +0200 Message-Id: <20211026114100.2593433-8-bigeasy@linutronix.de> In-Reply-To: <20211026114100.2593433-1-bigeasy@linutronix.de> References: <20211026114100.2593433-1-bigeasy@linutronix.de> MIME-Version: 1.0 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" The !in_atomic() check in _wait_for_atomic() triggers on PREEMPT_RT because the uncore::lock is a spinlock_t and does not disable preemption or interrupts. Changing the uncore:lock to a raw_spinlock_t doubles the worst case latency on an otherwise idle testbox during testing. Therefore I'm currently unsure about changing this. Link: https://lore.kernel.org/all/20211006164628.s2mtsdd2jdbfyf7g@linutronix.de/ Signed-off-by: Sebastian Andrzej Siewior --- drivers/gpu/drm/i915/i915_utils.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index 7a5925072466a..b7b56fb1e2fc7 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -344,7 +344,7 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms) #define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000) /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */ -#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT) +#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT) && !defined(CONFIG_PREEMPT_RT) # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic()) #else # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)