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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 3F4A9C4360F for ; Thu, 7 Mar 2019 21:23:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 12A5220675 for ; Thu, 7 Mar 2019 21:23:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726367AbfCGVX2 convert rfc822-to-8bit (ORCPT ); Thu, 7 Mar 2019 16:23:28 -0500 Received: from linux-libre.fsfla.org ([209.51.188.54]:38636 "EHLO linux-libre.fsfla.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726186AbfCGVX2 (ORCPT ); Thu, 7 Mar 2019 16:23:28 -0500 Received: from free.home (home.lxoliva.fsfla.org [172.31.160.164]) by linux-libre.fsfla.org (8.15.2/8.15.2/Debian-3) with ESMTP id x27LMrbu028749; Thu, 7 Mar 2019 21:22:56 GMT Received: from livre (livre.home [172.31.160.2]) by free.home (8.15.2/8.15.2) with ESMTP id x27LME4J377376; Thu, 7 Mar 2019 18:22:14 -0300 From: Alexandre Oliva To: Aaro Koskinen Cc: "Maciej W. Rozycki" , Tom Li , James Hogan , Jiaxun Yang , Huacai Chen , Ralf Baechle , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] On the Current Troubles of Mainlining Loongson Platform Drivers Organization: Free thinker, not speaking for FSF Latin America References: <20190208083038.GA1433@localhost.localdomain> <20190211125506.GA21280@localhost.localdomain> <20190211230614.GB22242@darkstar.musicnaut.iki.fi> <20190217235951.GA20700@darkstar.musicnaut.iki.fi> <20190307202156.GB30189@darkstar.musicnaut.iki.fi> Date: Thu, 07 Mar 2019 18:22:14 -0300 In-Reply-To: <20190307202156.GB30189@darkstar.musicnaut.iki.fi> (Aaro Koskinen's message of "Thu, 7 Mar 2019 22:21:56 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Scanned-By: MIMEDefang 2.84 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mar 7, 2019, Aaro Koskinen wrote: > Hi, > On Thu, Mar 07, 2019 at 03:41:01AM -0300, Alexandre Oliva wrote: >> On Feb 17, 2019, "Maciej W. Rozycki" wrote: >> >> > Is there an MMIO completion barrier missing there somewhere by any chance >> > causing an IRQ that has been handled already to be redelivered because an >> > MMIO write meant to clear the IRQ at its origin at handler's completion >> > has not reached its destination before interrupts have been reenabled in >> > the issuing CPU? Just a thought. >> >> I've finally got a chance to bisect the IRQ14 (nobody cared) regression >> on my yeeloong. It took me to MIPS: Enforce strong ordering for MMIO >> accessors (commit 3d474dacae72ac0f28228b328cfa953b05484b7f). > This is interesting, thanks for the research, but I'm afraid it doesn't seem > to be the root cause. Oh, I didn't mean to offer anything definitive, just to report the findings of my investigation so far, since I had no clue when I'd find another significant time slot to get back onto it. > Could you check your /proc/interrupts counters after the boot with > your change? 16k to 18k interrupts after booting up into multi-user mode, including some idle time (and possibly anacron jobs) in the case that got more interrupts. That's not unlike what I get with 4.19.26-gnu. -- Alexandre Oliva, freedom fighter https://FSFLA.org/blogs/lxo Be the change, be Free! FSF Latin America board member GNU Toolchain Engineer Free Software Evangelist Hay que enGNUrecerse, pero sin perder la terGNUra jamás-GNUChe