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 EC3E4CD98E0 for ; Mon, 15 Jun 2026 20:39:38 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 56C0F10E708; Mon, 15 Jun 2026 20:39:38 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="ZVjB7Q7S"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4A44510E708 for ; Mon, 15 Jun 2026 20:39:37 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 3385C44486; Mon, 15 Jun 2026 20:39:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6E231F000E9; Mon, 15 Jun 2026 20:39:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781555977; bh=98bAbI4gaGex3JmSfN5+zCVhCyTvdoXAT92LvlqfEOk=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=ZVjB7Q7SgqZPhQlIkzt3kj0EvDWvw8+kHCrYnkgldyOK/phmSC1jnZXbSH/5Vzqdb ncjuXSRqeprJQzQHAYhBlNiv2QJiRVclKRVErSj6MAU6nXASJBBq3ccwvkCXbROdgt bYylMCQg/OjpRgV0vH6pRXkaLjxof3BtMxJ8zhsMwdr64TvHOD1h7DvlTaOYMC17Qr XK28rwQMJaSY9xXQXMPJguNPZqR5j35VswUoCOolJ+IdSOdM3NVbPHqrwWRZ0daBAZ i+M9dHurjhy+1t1kTKy7fWGY2Ferb0S21Vo/fDuir14RvU0C+12pueKKZXrooRoKLR mcDuGqL/gik6Q== From: sashiko-bot@kernel.org Subject: Re: [PATCH v8 23/27] PREEMPT_RT injection To: "Maarten Lankhorst" Cc: dri-devel@lists.freedesktop.org In-Reply-To: <20260615201846.307297-24-dev@lankhorst.se> References: <20260615201846.307297-24-dev@lankhorst.se> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 15 Jun 2026 20:39:36 +0000 Message-Id: <20260615203936.E6E231F000E9@smtp.kernel.org> 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: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 2 potential issue(= s) to consider: - [High] PREEMPT_RT is unconditionally enabled for all supported architectu= res, removing the user prompt. - [High] DRM_I915_DEBUG_VBLANK_EVADE is moved to the DRM_XE Kconfig and for= cefully enabled, breaking i915-only builds. -- commit 64632b1f6e588fa66b14871b397cbf599d637abc Author: Maarten Lankhorst PREEMPT_RT injection This commit forces PREEMPT_RT to be unconditionally enabled for supported architectures. It also moves DRM_I915_DEBUG_VBLANK_EVADE from the i915 Kconfig to the xe Kconfig, enabling it by default. > diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kc= onfig.debug > index 52a3a59b4ba2c..5977d0b262b85 100644 > --- a/drivers/gpu/drm/i915/Kconfig.debug > +++ b/drivers/gpu/drm/i915/Kconfig.debug [ ... ] > -config DRM_I915_DEBUG_VBLANK_EVADE > - bool "Enable extra debug warnings for vblank evasion" > - depends on DRM_I915 > - default n > - help > - Choose this option to turn on extra debug warnings for the > - vblank evade mechanism. This gives a warning every time the > - the deadline allotted for the vblank evade critical section > - is exceeded, even if there isn't an actual risk of missing > - the vblank. > - > - Recommended for driver developers only. > - > - If in doubt, say "N". > - > config DRM_I915_DEBUG_RUNTIME_PM > diff --git a/drivers/gpu/drm/xe/Kconfig.debug b/drivers/gpu/drm/xe/Kconfi= g.debug > index 01227c77f6d70..1d5f11c6e88f3 100644 > --- a/drivers/gpu/drm/xe/Kconfig.debug > +++ b/drivers/gpu/drm/xe/Kconfig.debug [ ... ] > @@ -30,6 +30,11 @@ config DRM_XE_DEBUG > =20 > If in doubt, say "N". > =20 > +config DRM_I915_DEBUG_VBLANK_EVADE > + def_bool y > + depends on DRM_XE > + [Severity: High] Does this code break the vblank evasion debug logic for i915-only builds? By moving DRM_I915_DEBUG_VBLANK_EVADE out of i915 and defining it as def_bool y with a dependency on DRM_XE, developers building only i915 can no longer enable this feature.=20 Additionally, does this unconditionally force the extra debug warnings and overhead on all xe driver users without providing a way to opt out? > + > config DRM_XE_DEBUG_VM > diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt > index 88c594c6d7fcd..11bec9be95405 100644 > --- a/kernel/Kconfig.preempt > +++ b/kernel/Kconfig.preempt [ ... ] > @@ -90,9 +90,9 @@ config PREEMPT_LAZY > endchoice > =20 > config PREEMPT_RT > - bool "Fully Preemptible Kernel (Real-Time)" > - depends on EXPERT && ARCH_SUPPORTS_RT && !COMPILE_TEST > + def_bool y > select PREEMPTION > + depends on ARCH_SUPPORTS_RT [Severity: High] Does this change unintentionally force a Real-Time kernel build on any architecture where ARCH_SUPPORTS_RT is true? By changing PREEMPT_RT to def_bool y and removing the prompt, it appears users are completely prevented from selecting standard preemption models like PREEMPT_NONE or PREEMPT_VOLUNTARY.=20 This universally alters locking semantics across the entire kernel (for example, converting spinlocks to rt_mutexes) regardless of whether drivers = or systems are prepared for RT. > help > This option turns the kernel into a real-time kernel by replacing > various locking primitives (spinlocks, rwlocks, etc.) with --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260615201846.3072= 97-1-dev@lankhorst.se?part=3D23