From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 46E0A1E0B74 for ; Mon, 21 Oct 2024 20:56:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729544183; cv=none; b=rdeFFaOb9xDo2RriVBw5T6V8aEPze6bveQqiFiTqB435iKjXAxFxwKJfp4JCjotvMQ98KBjtQDUV0BwsLGvPJcAFBwFAJ4ioUv30M/mMTFBM0e1N/8GJVYyeItcssr+34WduggNcAgACyF3/8uRezUbqlyZJdbRJ2lnQKp772SE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729544183; c=relaxed/simple; bh=5Efa6JPsgPAmLs9phPgQUzu9dFdIh0K8xBxCAjbxBY0=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=YuYQyGtUrR2VIqXSq9TdALSNzDedjPLD26nx3oahshTVg5rRNfHJNB9+gvWXHnCUP5m7DATFzcqISlyApDya7fJt978aayGuC4tvuZLxDRGtzhSYgknJPWAJ/V3SSQhwY9v3D3tcc5aLvhT11UVZwQG9ZdXrmIH94lh9KFE5S6Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=JxFjpNmf; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=0jWekIhK; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="JxFjpNmf"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="0jWekIhK" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1729544179; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FYVhaPxM510U0zYvoJtG3TSO0Ajm2Y0B1WvIHsfGUVE=; b=JxFjpNmfZnzqPud2EEdGxssdSQieebV0vZ5Z46K9aoxvTEUHsNVl1xN5yUKuRire/ClnRa MM/XHyGs166YmYfsuoYJ7SqHueqNUBfVGM09UxJK4ZJD2uwJglFDr9b6RaW0XUGWHrzd8m aVIIs41z0mM4Tg1pgFbfkRgVxCS3gdM7eY8Sd26ioaT1gr/UXmvpmP2qXND1dmlSv5WB4p QILUzfkGzbmXkZ37MwfWWBzUYEwQWQEmg2ZoOu50UHOwOjDx6YDlJTwsHZ6HSDJVw6UwXQ 3I982UlvUVv51lc9B7Ozup1miQ8knHehN8OkzKL4uSuKQHDI3Deb8xHFBwaA+g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1729544179; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FYVhaPxM510U0zYvoJtG3TSO0Ajm2Y0B1WvIHsfGUVE=; b=0jWekIhKMbb5HF6exMOtepXI0UE1+bnVgTXKa3YOPdKyYQOMZtKIKeAGhpohvl2BZpecUk dC5yRWosWwLwSQDw== To: debarbos@redhat.com, williams@redhat.com Cc: linux-rt-users@vger.kernel.org Subject: Re: [PATCH] v6.6-rt-stable: printk/nbcon: Fix Illegal RCU Usage In-Reply-To: References: Date: Mon, 21 Oct 2024 23:02:18 +0206 Message-ID: <84msix5g5p.fsf@jogness.linutronix.de> Precedence: bulk X-Mailing-List: linux-rt-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On 2024-10-21, Derek Barbosa wrote: > From 1188b21c357dcb750a6851d7e5fd2d1f70ca9690 Mon Sep 17 00:00:00 2001 > From: Derek Barbosa > Date: Mon, 21 Oct 2024 11:30:30 -0400 > Subject: [PATCH 1/1] [PATCH] printk: nbcon: Fix illegal RCU usage on thread > wakeup > > In debug kernels, printk'ing during the SMP startup of a secondary CPU > results in a splat [0] on boot that details illegal RCU usage from > offline CPUs. > > This patch aligns rcuwait_has_sleeper() with what currently exists in > Torvalds' tree, at commit 76f258bf3f2aa, and will avoid the > aforementioned splat. > > Furthermore, this patch makes it so that we avoid the use of hacky > rcu_derefrencing through the waiter's task struct,and instead leverages > the correct RCU API with the rcuwait_active() function. > > [0] https://lore.kernel.org/linux-rt-users/5x4nejpojrtny37k7l6loewqwuaituq77zc3tkkojvawcuvmml@thwg65fdb3vn/ > > Signed-off-by: Derek Barbosa Thanks! Reviewed-by: John Ogness