From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751267AbcDXEFe (ORCPT ); Sun, 24 Apr 2016 00:05:34 -0400 Received: from mail-pf0-f170.google.com ([209.85.192.170]:34068 "EHLO mail-pf0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750711AbcDXEFd (ORCPT ); Sun, 24 Apr 2016 00:05:33 -0400 Date: Sun, 24 Apr 2016 14:03:11 +0900 From: Sergey Senozhatsky To: Pavel Machek Cc: Sergey Senozhatsky , Andrew Morton , Jan Kara , Petr Mladek , Tejun Heo , Tetsuo Handa , linux-kernel@vger.kernel.org, Byungchul Park , Sergey Senozhatsky Subject: Re: [RFC][PATCH v4 0/2] printk: Make printk() completely async Message-ID: <20160424050311.GA587@swordfish> References: <1457964820-4642-1-git-send-email-sergey.senozhatsky@gmail.com> <20160423193608.GA15755@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160423193608.GA15755@amd> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On (04/23/16 21:36), Pavel Machek wrote: > > The patch set is based on slightly updated Jan Kara's patches. > > > > This patch set makes printk() completely asynchronous: new messages > > are getting upended to the kernel printk buffer, but instead of 'direct' > > printing the actual print job is performed by a dedicated kthread. > > This has the advantage that printing always happens from a schedulable > > context and thus we don't lockup any particular CPU or even > > interrupts. > > And that means that printk() will become mostly useless for debugging, > right? what do you mean? printk by default operates in 'old' sync mode and can be switched to async for those who experience problems with the sync one (whilst actually debugging). I'm not sure I got your point. -ss