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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A15D5C4CEC9 for ; Tue, 17 Sep 2019 11:20:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7829F214AF for ; Tue, 17 Sep 2019 11:20:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726781AbfIQLUm (ORCPT ); Tue, 17 Sep 2019 07:20:42 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41369 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726773AbfIQLUm (ORCPT ); Tue, 17 Sep 2019 07:20:42 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1iABXE-0002xr-6c; Tue, 17 Sep 2019 13:20:40 +0200 Date: Tue, 17 Sep 2019 13:20:40 +0200 From: Sebastian Andrzej Siewior To: Martin.Wirth@dlr.de Cc: linux-rt-users@vger.kernel.org Subject: Re: Long latencies during disk-io Message-ID: <20190917112039.nwzg3qfxrdwsa6t7@linutronix.de> References: <20190905154115.mnid6rue65x6vvt6@linutronix.de> <1A2AF5F768264E479963C4D8C015EB696C51159F@DLDEFFMIMP02EXC.intra.dlr.de> <1A2AF5F768264E479963C4D8C015EB696C515541@DLDEFFMIMP02EXC.intra.dlr.de> <20190913133655.2pbhnxm5ndcje3bk@linutronix.de> <1A2AF5F768264E479963C4D8C015EB696C51C1F1@DLDEFFMIMP02EXC.intra.dlr.de> <20190913150645.nqt4ekv466yby2a4@linutronix.de> <1A2AF5F768264E479963C4D8C015EB696C520504@DLDEFFMIMP02EXC.intra.dlr.de> <20190917105236.yf5btniiq4bjhimo@linutronix.de> <1A2AF5F768264E479963C4D8C015EB696C521875@DLDEFFMIMP02EXC.intra.dlr.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1A2AF5F768264E479963C4D8C015EB696C521875@DLDEFFMIMP02EXC.intra.dlr.de> User-Agent: NeoMutt/20180716 Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On 2019-09-17 11:09:31 [+0000], Martin.Wirth@dlr.de wrote: > Hi Sebastian, Hi Martin, > Maybe not. But this means that a lot of drivers which have no requirement > to be protected against softirq will have to be converted to make them fit for RT. > But maybe I'm wrong and most RT applications are triggered by the timer > and not by some io-card... Your argument is valid. If we don't disable softirqs while force-threading then we need duct-tape in other places. So it is not ideal. Now we know that this seems to be problem. > Thanks again for all the work! > > Martin Sebastian