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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26912C43331 for ; Fri, 6 Sep 2019 19:54:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDEA120842 for ; Fri, 6 Sep 2019 19:54:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="D1gmX8qh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394010AbfIFTyD (ORCPT ); Fri, 6 Sep 2019 15:54:03 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:41726 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727004AbfIFTyC (ORCPT ); Fri, 6 Sep 2019 15:54:02 -0400 Received: by mail-pg1-f195.google.com with SMTP id x15so4079235pgg.8 for ; Fri, 06 Sep 2019 12:54:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=VpEKZIToJcJNtnrt6GtVJ64TAfq7GPSof5ZG1aF07lE=; b=D1gmX8qhzlfB/Pv7zyAZj4Fdbl/Ww/xUcMUcOizFDGiz+svCTiSk/J5vhlLzfJy0Fj mQU4m/XKA8lbeph7b0Djr18inpjH01goTUNDbFmzlzPlravDK0d/QCxXlfRpROLz4n2p XbwNqzzZwfNRQoe/5bo+dJVhCjyvS6YqH5L98KFp2qbCc0jMtRsbPozPmb+0/hnwJCRh UhE4Igys1vXpOkk/JgAyeR/7M86hqQLiZiZgIF97NUxxeNzaZ36E4dT1dhOGVEVDj0tI Q0YIRbW9gQOeHMgI1w3SJvA0vU5qJ54bzYnlkawU+fP6Ikbey+r7jjvVuDyoNkWQKDgo oGOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=VpEKZIToJcJNtnrt6GtVJ64TAfq7GPSof5ZG1aF07lE=; b=JJxrMOQ3Br3XZq5QPJcC82Dc51bvQou20cQ2zKdEif9UhZdTSPNslkm0Q8TieDUcKF grOHGHh00WjmmsMAo5yzHOA/6phWwRJ9FmhE5H3QmmbnRQ5xmFp+8KSu1+WHxVkRB6YY ONZHByEIADFYubNRc36H5t11vmF/n1b9sB2yawmQPQtyasv4BJ1gSXE/ZAkD4uoVOy83 YQ9F27dpx0jxv2wD/USIAkxngmLfGb+aihKTchs16e0eXmwzLs1MyBlbPCQQNqZcMBag g1WXpclEC1hJQKLODWQ8iwt7+3+Ok8eHChJtyt2WrnshmyI8d1z97CZnYoSqY1ceo2IN c+5A== X-Gm-Message-State: APjAAAWxZWLYfQULsSZX+3UzrzoVw/hudvWBEVA3dkguJzakL1RtLYeT XcUz0N1ObGBEroIqthHTFBo= X-Google-Smtp-Source: APXvYqxNtcNcExy7Z7dsvZlivPZODRshEiZdXLLiHzW3C0Sb63CyGltsOeH3x/I+o5Cj4kpWO2opUg== X-Received: by 2002:a17:90a:8a02:: with SMTP id w2mr10511834pjn.131.1567799642060; Fri, 06 Sep 2019 12:54:02 -0700 (PDT) Received: from localhost ([121.137.63.184]) by smtp.gmail.com with ESMTPSA id g2sm7614527pfm.32.2019.09.06.12.54.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Sep 2019 12:54:01 -0700 (PDT) From: Sergey Senozhatsky X-Google-Original-From: Sergey Senozhatsky Date: Sat, 7 Sep 2019 04:53:59 +0900 To: Peter Zijlstra Cc: Petr Mladek , Andrea Parri , Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , Brendan Higgins , John Ogness , Thomas Gleixner , Linus Torvalds , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v4 0/9] printk: new ringbuffer implementation Message-ID: <20190906195359.GB69785@tigerII.localdomain> References: <20190807222634.1723-1-john.ogness@linutronix.de> <20190904123531.GA2369@hirez.programming.kicks-ass.net> <20190905130513.4fru6yvjx73pjx7p@pathway.suse.cz> <20190905143118.GP2349@hirez.programming.kicks-ass.net> <20190906090627.GX2386@hirez.programming.kicks-ass.net> <20190906124211.2dionk2kzcslaotz@pathway.suse.cz> <20190906140126.GY2349@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190906140126.GY2349@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (09/06/19 16:01), Peter Zijlstra wrote: > > 2. The simple approach works only with lockless consoles. We need > > something else for the rest at least for NMI. Simle offloading > > to a kthread has been blocked for years. People wanted the > > trylock-and-flush-immediately approach. > > Have an irq_work to wake up a kthread that will print to shit consoles. Do we need sched dependency? We can print a batch of pending logbuf messages and queue another irw_work if there are more pending messages, right? -ss