From patchwork Fri Aug 30 15:28:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Ogness X-Patchwork-Id: 824337 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 95EA71B2EC2; Fri, 30 Aug 2024 15:29:24 +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=1725031766; cv=none; b=abCDhbGHEQJkYEfELBmSE/DSaxLhCWtc3yy2Jd52U0V4GcJqW/jKUhPGXZEHjJ8hWIYcNLoE6XwH7tR2+th4XsBxhG9UhXqv+ObN3OG9TxMtCXgnzuJcGRGjk8tI+nS5tJ4SuntyIy+mvmOYRK+wdgiRbmlGqexiQy0tbug3POw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725031766; c=relaxed/simple; bh=L65dIVCQsA3YEQ+epYP0GMz7az8+WBN2eBvhQlPRoEc=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=J5685xWVoHowa51dUQ3MKkiSWZG32wtF6e16xc7+lRQy72APk7rcPObxgy77MwZ5UEvj6bzJU6wEf59N013N9CW2ONPNPXvXERDmNDGT9wpvXqEIStF9/10HRFTUhLjDEw0ueVQXK0hE24heiXZ0wzLJteSOVVBH8wZ2aQ/Zllc= 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=OZ5J/hWe; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=GDjSQVuM; 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="OZ5J/hWe"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="GDjSQVuM" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1725031756; 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; bh=vR1IcGcO4X3GJ9y3yerSnFs54fwhhftvCVldJT0Dsjg=; b=OZ5J/hWeqzI9/J/suXmCtftj2bkJmgZkjDA3MqC//S8rWbw04Gx2hlCGlnowxuAZJKBKDo bRfO76Lv/tMjhSmh1Q/UdLTs2lW4DaU2xB0DTpL0bB/FZJoDL/rrrl5xSFiO34cE2xoI4w GN/ie92RNdNL/F71FtZjFCaKeU/oTIbSaS/nLqESqFFPX/aj2Bzwspdh+LN77qLrdHD9Zy a0HTgs6WAbvvLbvfaPGv6n76Tmu6NHdNLOUx76I9gVozn7tIqVG6yA9hTc92IQJQoqBUm0 sEoY05zvnfHTJrzwDHuTskm5bInID+bCSmAqxlclwU1PHgV1rhsBtPB8yFPKvQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1725031756; 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; bh=vR1IcGcO4X3GJ9y3yerSnFs54fwhhftvCVldJT0Dsjg=; b=GDjSQVuMlXT6r0Miwt04f1N7brPYutKIY9enj6pwc1BrXCPA8i+Wlqi7PAAw5mPpdF/nAM KdT7U7BmDx/mhvCw== To: Petr Mladek Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , linux-fsdevel@vger.kernel.org, Jiri Slaby , linux-serial@vger.kernel.org Subject: [PATCH printk v5 00/17] add threaded printing + the rest Date: Fri, 30 Aug 2024 17:34:59 +0206 Message-Id: <20240830152916.10136-1-john.ogness@linutronix.de> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Hi, This is v5 of a series to implement threaded console printing as well as some other minor pieces (such as proc and sysfs recognition of nbcon consoles). v4 is here [0]. For information about the motivation of the nbcon consoles, please read the cover letter of the original v1 [1]. This series provides the remaining pieces of the printk rework. All other components are either already mainline or are currently in linux-next. In particular this series does: - Implement dedicated printing threads per nbcon console. - Implement forced threading of legacy consoles for PREEMPT_RT. - Implement nbcon support for proc and sysfs console-related files. - Provide a new helper function nbcon_reacquire_nobuf() to allow nbcon console drivers to reacquire ownership. Note that this series does *not* provide an nbcon console driver. That will come in a follow-up series. Here are the changes since v4: - For nbcon_kthread_create(), add more explanations about the context and rules to the kerneldoc. - In nbcon_alloc(), clear con->pbufs on failure. - Remove legacy_kthread_wake() and add its functionality to wake_up_klogd_work_func() since it was the only call site. - In console_start(), allow triggering the legacy loop if it is an nbcon. There might be a registered boot console. - In __pr_flush(), add atomic flushing before wait loop. - In console_try_replay_all(), add atomic flushing. John Ogness [0] https://lore.kernel.org/lkml/20240827044333.88596-1-john.ogness@linutronix.de [1] https://lore.kernel.org/lkml/20230302195618.156940-1-john.ogness@linutronix.de John Ogness (16): printk: nbcon: Add function for printers to reacquire ownership printk: Fail pr_flush() if before SYSTEM_SCHEDULING printk: Flush console on unregister_console() printk: nbcon: Add context to usable() and emit() printk: nbcon: Init @nbcon_seq to highest possible printk: nbcon: Relocate nbcon_atomic_emit_one() printk: nbcon: Use thread callback if in task context for legacy printk: nbcon: Rely on kthreads for normal operation printk: Provide helper for message prepending printk: nbcon: Show replay message on takeover proc: consoles: Add notation to c_start/c_stop proc: Add nbcon support for /proc/consoles tty: sysfs: Add nbcon support for 'active' printk: Implement legacy printer kthread for PREEMPT_RT printk: nbcon: Assign nice -20 for printing threads printk: Avoid false positive lockdep report for legacy printing Thomas Gleixner (1): printk: nbcon: Introduce printer kthreads drivers/tty/tty_io.c | 2 +- fs/proc/consoles.c | 7 +- include/linux/console.h | 48 +++ kernel/printk/internal.h | 82 ++++- kernel/printk/nbcon.c | 504 +++++++++++++++++++++++++----- kernel/printk/printk.c | 465 ++++++++++++++++++++++++--- kernel/printk/printk_ringbuffer.h | 2 + kernel/printk/printk_safe.c | 4 +- 8 files changed, 981 insertions(+), 133 deletions(-) base-commit: 59cd94ef80094857f0d0085daa2e32badc4cddf4