From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) by kanga.kvack.org (Postfix) with ESMTP id 09D1D6B06F9 for ; Fri, 9 Nov 2018 09:08:36 -0500 (EST) Received: by mail-lf1-f69.google.com with SMTP id j131so195066lfg.14 for ; Fri, 09 Nov 2018 06:08:35 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id j3-v6sor4967763ljc.22.2018.11.09.06.08.33 for (Google Transport Security); Fri, 09 Nov 2018 06:08:33 -0800 (PST) Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com. [209.85.167.44]) by smtp.gmail.com with ESMTPSA id q30sm1450612lfi.94.2018.11.09.06.08.30 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Nov 2018 06:08:31 -0800 (PST) Received: by mail-lf1-f44.google.com with SMTP id q6-v6so1404106lfh.9 for ; Fri, 09 Nov 2018 06:08:30 -0800 (PST) MIME-Version: 1.0 References: <1541165517-3557-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <1541165517-3557-3-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20181107151900.gxmdvx42qeanpoah@pathway.suse.cz> <20181108044510.GC2343@jagdpanzerIV> <9648a384-853c-942e-6a8d-80432d943aae@i-love.sakura.ne.jp> <20181109061204.GC599@jagdpanzerIV> In-Reply-To: <20181109061204.GC599@jagdpanzerIV> From: Linus Torvalds Date: Fri, 9 Nov 2018 08:08:13 -0600 Message-ID: Subject: Re: [PATCH 3/3] lockdep: Use line-buffered printk() for lockdep messages. Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: sergey.senozhatsky.work@gmail.com Cc: penguin-kernel@i-love.sakura.ne.jp, Petr Mladek , Sergey Senozhatsky , dvyukov@google.com, Steven Rostedt , glider@google.com, fengguang.wu@intel.com, jpoimboe@redhat.com, Linux List Kernel Mailing , Andrew Morton , linux-mm@kvack.org, Ingo Molnar , Peter Zijlstra , Will Deacon On Fri, Nov 9, 2018 at 12:12 AM Sergey Senozhatsky wrote: > > Dunno. I guess we still haven't heard from Linus because he did quite a good > job setting up his 'email filters' ;) Not filters, just long threads that I lurk on. I don't actually care too much about this - the part I care about is that when panics etc happen, things go out with a true best effort. And "best effort" actually means "reality", not "theory". I don't care one whit for some broken odd serial console that has a lock and deadlocks if you get a panic just in the right place. I care about the main printk/tty code doing the right thing, and avoiding the locks with the scheduler and timers etc. So the timestamping and wakeup code needing locks - or thinking you can delay things and print them out later (when no later happens because you're panicing in an NMI) - *that* is what I care deeply about. Something like having a line buffering interface for random debugging messages etc, I just don't get excited about. It just needs to be simple enough and robust enough. You guys seem to be talking it out ok. Linus