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 586474438B for ; Mon, 19 Aug 2024 19:23:17 +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=1724095399; cv=none; b=mqyqEX1YHUJ06xNM/+Yey/GdOK8KYhvQu/rHYtbbgNNR54dzO/q70+Qq6uJ/m7WhyY/Aq3JmscZAjcXcz4VTZd+5P1a259hnr7DFL7VVV7aPpHa/I7rXhrUZQkyAky4A2NuN+th7XsGBOIC9hpp/hlQ0DwEsAbE38EGLD4QCHUc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724095399; c=relaxed/simple; bh=W6WoE9R/tdk2wsQggdsp1NX6C01qnbzE7y5N3Z5FJIU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ZTj4/yZwzVBV47cY2C8sVWHln+wu4g1aQqvposfWkD7C8HEcd36TIot/JjzGwUNfxjRItjdWxuMPtyeL/wHijwqONAROaVYfCh3eqSkBgclW1A9UMslqlrz0GauSXAr8a7Q/nex3xmlIJotK9Kk73pi/K9wYfOfaQdUnOhrVNpc= 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=tHd049/5; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ByLpgSbW; 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="tHd049/5"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ByLpgSbW" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1724095395; 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=dQ7Awp8jlfo+IRT/QjM/los97UHko8NLNXkxPXn2rYY=; b=tHd049/5cf8ggWsgnTWl9mNyLJc79tEfcmFjlNg8hjzHU1zMb85ZK1nAOyF0JktzUHz2IU dRO4zUnvpwPFQK6jNSv4/K+Qo6ixQ8zgGN2hVkBML4UOW54aQujnsxLkbfCDHXL3lfR8oT tANlPolwYwr3lEdauRQyo3iNkVRVH2L85oX5+yH9iu6XR1slO92Uzk3LqpvQ4Ve47T0klC xT8tTl6SnxPc1mFkclpHnCKeKR95UVkJL59bKvNWTRcl1zCGocuh07vXEgAJmlVmeXLyQp rDyZJda2QmhVUGUAMXyenYoBAXmstg99L3L9OhYxKfvSJ74rsAnLQ2/XlhSi7Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1724095395; 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=dQ7Awp8jlfo+IRT/QjM/los97UHko8NLNXkxPXn2rYY=; b=ByLpgSbWqK9kFdsbcWR3GIS9N8k1XBpf0L0RQatoPi1tDe4DHo8UpgL+GvfdEU5Ck99z/a 3nuAAmMgzVy5XbAQ== To: Petr Mladek , takakura@valinux.co.jp Cc: rostedt@goodmis.org, senozhatsky@chromium.org, akpm@linux-foundation.org, bhe@redhat.com, lukas@wunner.de, wangkefeng.wang@huawei.com, ubizjak@gmail.com, feng.tang@intel.com, j.granados@samsung.com, stephen.s.brennan@oracle.com, linux-kernel@vger.kernel.org, nishimura@valinux.co.jp, taka@valinux.co.jp Subject: Re: [PATCH v3 2/2] Handle flushing of CPU backtraces during panic In-Reply-To: References: <20240812072137.339644-1-takakura@valinux.co.jp> <20240812072931.339735-1-takakura@valinux.co.jp> Date: Mon, 19 Aug 2024 21:29:14 +0206 Message-ID: <87y14sjp0d.fsf@jogness.linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On 2024-08-13, Petr Mladek wrote: > I would do something like: > > /** > * console_try_or_trigger_flush - try to flush consoles directly when > * safe or the trigger deferred flush. > * > * Context: Any > */ > void console_try_or_trigger_flush(void) > { > if (!is_printk_legacy_deferred() && console_trylock()) > console_unlock(); > else > defer_console_output(); > } > > and use it instead of printk_trigger_flush() in > nmi_trigger_cpumask_backtrace(). Just to be clear, you are talking about removing printk_trigger_flush() entirely and instead provide the new console_try_or_trigger_flush()? Which then also involves updating the call sites: lib/nmi_backtrace.c:nmi_trigger_cpumask_backtrace() arch/powerpc/kernel/watchdog.c:watchdog_timer_interrupt() > Well, I would postpone this patch after we finalize the patchset > adding con->write_atomic() callback. This patch depends on it anyway > via is_printk_legacy_deferred(). The patchset might also add > other wrappers for flushing consoles and we have to choose some > reasonable names. I agree. Let's finish up the atomic series and then we can worry about this. John