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 575EF214A92; Mon, 31 Mar 2025 14:35:51 +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=1743431752; cv=none; b=KZHy4oPXg6unH14hymedI1l0bTaKjzOAHL+2yYeMJQspECNBC0+9IjntYFtRlk+IjO87NRjW3H4HZKVOFrvFS0WxKKB77kcPTszt4nItydSRFyxhuqS3wIEONcpOpMokVJnAYDsXCmumn6MM4QgFJcLV3P+IOor+2Fo2zlwFYi0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743431752; c=relaxed/simple; bh=ph6kfzHAh0EM3oPxVjEcnTH6scR9G5BgbmruTaFYM0k=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=P+jU2vF5/XN9dyUtAAkZxwqTMnZ2tdo2RoAylROwfdlm27Myq4YQBtQCEjlo9zzPXX++zxzK7sRpuiXmXIkS6kZ+1vsSePRJM9f1OVw/z/xhw//flFmhZSoTaxYqJXvPYiAY1m0ws1upFYyC8Ep2wJNoPLu3BmpJbvfqQvaTdrw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YwJYPg3b; 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="YwJYPg3b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 156F7C4CEE4; Mon, 31 Mar 2025 14:35:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743431751; bh=ph6kfzHAh0EM3oPxVjEcnTH6scR9G5BgbmruTaFYM0k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YwJYPg3bBzwSCHHTvLDZ6d3WMnU/516dmADQ213qGvSrVjS4vXUbvFp/APk774GtP ZNapE+X0XQIQ5OKFUlEogem/6FX/GyPMa/812sg5XOxFtRt5LnHCfXBwjDJ/igknIQ OUOhVEwzdTVl634qlNFU2HnJa9lZufHSzZMRhvIXksM6dr+KEQeCal4Au4t81mdbW8 idrUUKLJDRM0eO5WaLjVWQaR7i4qNJP2YvTQE20cJWqIIzpofZQW6IcVScqrl1/yXU euxoGutpgM0Bmj7mGazpB+ehZSVvYMjqGn18qCKKA36nB15KcFxWdAbsEdunoJmrPW fA60SS6fJvh9g== 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, wei.liu@kernel.org, linux@weissschuh.net, zhangguopeng@kylinos.cn, linux-rt-devel@lists.linux.dev Subject: [PATCH AUTOSEL 6.12 09/13] Flush console log from kernel_power_off() Date: Mon, 31 Mar 2025 10:35:23 -0400 Message-Id: <20250331143528.1685794-9-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250331143528.1685794-1-sashal@kernel.org> References: <20250331143528.1685794-1-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 6.12.21 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 eca9bb2ee637b..0cb647ecd77f5 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -204,6 +204,7 @@ 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) @@ -304,6 +305,11 @@ 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 3b75f6e8410b9..881a26e18c658 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2436,7 +2436,6 @@ 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 */ @@ -2449,7 +2448,6 @@ 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 */ @@ -4436,7 +4434,7 @@ 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 f05dbde2c93fe..d6ee090eda943 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -697,6 +697,7 @@ 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