From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 96F2721D596; Mon, 31 Mar 2025 14:34:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743431680; cv=none; b=n+gAB90fPpzhxuKWfBrLh0HP0Xm1v3PeazeQXokc4d9mEgNPAKZPaHkj2YHTYysEeYLmanyqyyd+C0S3cwT4buu9C9I2pz5RoONMhqeb3RUtjEH0QIHD9dxCXcn/UL8IGlSooizc8zLXggNDj95AYPJcOgaildswi5RZkqTwmCo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743431680; c=relaxed/simple; bh=WGh2VH/p78vjglhZ0w1dJgel8kTb2gHFjJxvKjKveHE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=UgsmhcKUJWMJG27Y0+Kxx2O+gs1UnOrqnL5KOKSbY11Magach5UK7EG7Um887uy7iqiIE3FFX6+wumP3rBSo9EM/1hluTF6sySKawgQWUp7NqFH+a17BoQUbWKgjYM1bUhB4e2joMFe2sfYZG+XYtvdSyq8GPjpe+ikOInYwB8Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hOeinx5j; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hOeinx5j" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A821C4CEE9; Mon, 31 Mar 2025 14:34:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743431680; bh=WGh2VH/p78vjglhZ0w1dJgel8kTb2gHFjJxvKjKveHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hOeinx5ja3k+70BcmIjI9fftl2hKSFpoI+E+bBw7TmbwP31+o5C7Di3SPBY6LyUn6 l7tCAQVR1B1fJmCB5mR8HxpPJfT0OlxjKwvvoxS77/IP/K7qytUC6HDd/9ja8XB6tV ve2+A+YpOYICJErnuMZvIeYgRqepdk8wikHrWEAyfipNuKrUQBvhP6mCpfYN42U9rW yJbEvKQLFwGT0YjhPhYIkBm4Qs8e5wCtUCiS2Iiqn3tEDoVkx8Y4THOor2RTL9sCz0 mTUMuVaNLN+1c548fKpXf14n+qoTO35ASwvM4epKF2LAEEzQQdPhtZCFZGm1w4N7s8 PHtO/Ic9jsuKQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Paul E. McKenney" , John Ogness , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Boqun Feng , Sasha Levin , bigeasy@linutronix.de, clrkwllms@kernel.org, joel.granados@kernel.org, akpm@linux-foundation.org, jani.nikula@intel.com, ashutosh.dixit@intel.com, linux@weissschuh.net, zhangguopeng@kylinos.cn, linux-rt-devel@lists.linux.dev Subject: [PATCH AUTOSEL 6.14 12/18] Flush console log from kernel_power_off() Date: Mon, 31 Mar 2025 10:34:02 -0400 Message-Id: <20250331143409.1682789-12-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250331143409.1682789-1-sashal@kernel.org> References: <20250331143409.1682789-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.14 Content-Transfer-Encoding: 8bit From: "Paul E. McKenney" [ Upstream commit 6ea9a1781c70a8be1fcdc49134fc1bf4baba8bca ] Kernels built with CONFIG_PREEMPT_RT=y can lose significant console output and shutdown time, which hides shutdown-time RCU issues from rcutorture. Therefore, make pr_flush() public and invoke it after then last print in kernel_power_off(). [ paulmck: Apply John Ogness feedback. ] [ paulmck: Appy Sebastian Andrzej Siewior feedback. ] [ paulmck: Apply kernel test robot feedback. ] Signed-off-by: Paul E. McKenney Reviewed-by: John Ogness Reviewed-by: Petr Mladek Cc: Steven Rostedt Cc: Sergey Senozhatsky Link: https://lore.kernel.org/r/5f743488-dc2a-4f19-bdda-cf50b9314832@paulmck-laptop Signed-off-by: Boqun Feng Signed-off-by: Sasha Levin --- include/linux/printk.h | 6 ++++++ kernel/printk/printk.c | 4 +--- kernel/reboot.c | 1 + 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/include/linux/printk.h b/include/linux/printk.h index 4217a9f412b26..5b462029d03c1 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -207,6 +207,7 @@ void printk_legacy_allow_panic_sync(void); extern bool nbcon_device_try_acquire(struct console *con); extern void nbcon_device_release(struct console *con); void nbcon_atomic_flush_unsafe(void); +bool pr_flush(int timeout_ms, bool reset_on_progress); #else static inline __printf(1, 0) int vprintk(const char *s, va_list args) @@ -315,6 +316,11 @@ static inline void nbcon_atomic_flush_unsafe(void) { } +static inline bool pr_flush(int timeout_ms, bool reset_on_progress) +{ + return true; +} + #endif bool this_cpu_in_panic(void); diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 07668433644b8..057db78876cd9 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2461,7 +2461,6 @@ asmlinkage __visible int _printk(const char *fmt, ...) } EXPORT_SYMBOL(_printk); -static bool pr_flush(int timeout_ms, bool reset_on_progress); static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress); #else /* CONFIG_PRINTK */ @@ -2474,7 +2473,6 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre static u64 syslog_seq; -static bool pr_flush(int timeout_ms, bool reset_on_progress) { return true; } static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress) { return true; } #endif /* CONFIG_PRINTK */ @@ -4466,7 +4464,7 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre * Context: Process context. May sleep while acquiring console lock. * Return: true if all usable printers are caught up. */ -static bool pr_flush(int timeout_ms, bool reset_on_progress) +bool pr_flush(int timeout_ms, bool reset_on_progress) { return __pr_flush(NULL, timeout_ms, reset_on_progress); } diff --git a/kernel/reboot.c b/kernel/reboot.c index b5a8569e5d81f..41ab9e1ba3575 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -704,6 +704,7 @@ void kernel_power_off(void) migrate_to_reboot_cpu(); syscore_shutdown(); pr_emerg("Power down\n"); + pr_flush(1000, true); kmsg_dump(KMSG_DUMP_SHUTDOWN); machine_power_off(); } -- 2.39.5