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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EBAEC433EF for ; Thu, 21 Apr 2022 21:23:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442080AbiDUV0n (ORCPT ); Thu, 21 Apr 2022 17:26:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1442012AbiDUVZu (ORCPT ); Thu, 21 Apr 2022 17:25:50 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EA664D26A for ; Thu, 21 Apr 2022 14:23:00 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1650576178; 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=FJyzVroUiPfgU7SztA4gPo8aLMt6OzmOVTIELeRi4zk=; b=aWgkbWnlc7+Vjj5eLKBPrEi2Ayy5DpTlhdvwljtRNKsh/0op00hq4DaM2V5ANZ64A9u2RU lImTyH9sOqySvfAcidThdZ1RXxj0k8+1Js7tcxNFjto0ajfQaMtfy/u7trRLLENcZXCQx8 9CHJMLKQzFthP1HMZpRq3rQH4Yb0KmtKqhLJdY8iMItGaQctXhCpAQui9mIFxGTwBcmArM M4U/ZsDvVJYMerYhR/wLlYH7JqCRA7W4wykGDZMwn4L/CHhymtZ9kvp+mMwoNqkkTIaXsE /zGf7QQ4JL8qPqlbw3KHz/mCTQnBVBgWQJeROVGzCZSwTaFPpEpLT9tUOKHHzA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1650576178; 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=FJyzVroUiPfgU7SztA4gPo8aLMt6OzmOVTIELeRi4zk=; b=9nlPxVXdMN1qoHwqUPQ1I54gic5dBlNPJiYlt8kL5UJg9zWgOZnzFI/knO+CRST/C8H49l 2tdzS+pcjR2NbGDA== To: Petr Mladek Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: [PATCH printk v4 15/15] printk: remove @console_locked Date: Thu, 21 Apr 2022 23:28:50 +0206 Message-Id: <20220421212250.565456-16-john.ogness@linutronix.de> In-Reply-To: <20220421212250.565456-1-john.ogness@linutronix.de> References: <20220421212250.565456-1-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The static global variable @console_locked is used to help debug VT code to make sure that certain code paths are running with the console_lock held. However, this information is also available with the static global variable @console_kthreads_blocked (for locking via console_lock()), and the static global variable @console_kthreads_active (for locking via console_trylock()). Remove @console_locked and update is_console_locked() to use the alternative variables. Signed-off-by: John Ogness Reviewed-by: Petr Mladek --- kernel/printk/printk.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 7243a85564ef..f4a939304a12 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -340,15 +340,7 @@ static void console_kthreads_unblock(void) console_kthreads_blocked = false; } -/* - * This is used for debugging the mess that is the VT code by - * keeping track if we have the console semaphore held. It's - * definitely not the perfect debug tool (we don't know if _WE_ - * hold it and are racing, but it helps tracking those weird code - * paths in the console code where we end up in places I want - * locked without the console semaphore held). - */ -static int console_locked, console_suspended; +static int console_suspended; /* * Array of consoles built from command line options (console=) @@ -2719,7 +2711,6 @@ void console_lock(void) if (console_suspended) return; console_kthreads_block(); - console_locked = 1; console_may_schedule = 1; } EXPORT_SYMBOL(console_lock); @@ -2744,15 +2735,26 @@ int console_trylock(void) up_console_sem(); return 0; } - console_locked = 1; console_may_schedule = 0; return 1; } EXPORT_SYMBOL(console_trylock); +/* + * This is used to help to make sure that certain paths within the VT code are + * running with the console lock held. It is definitely not the perfect debug + * tool (it is not known if the VT code is the task holding the console lock), + * but it helps tracking those weird code paths in the console code such as + * when the console is suspended: where the console is not locked but no + * console printing may occur. + * + * Note: This returns true when the console is suspended but is not locked. + * This is intentional because the VT code must consider that situation + * the same as if the console was locked. + */ int is_console_locked(void) { - return (console_locked || atomic_read(&console_kthreads_active)); + return (console_kthreads_blocked || atomic_read(&console_kthreads_active)); } EXPORT_SYMBOL(is_console_locked); @@ -2808,8 +2810,6 @@ static inline bool console_is_usable(struct console *con) static void __console_unlock(void) { - console_locked = 0; - /* * Depending on whether console_lock() or console_trylock() was used, * appropriately allow the kthread printers to continue. @@ -3127,7 +3127,6 @@ void console_unblank(void) } else console_lock(); - console_locked = 1; console_may_schedule = 0; for_each_console(c) if ((c->flags & CON_ENABLED) && c->unblank) -- 2.30.2