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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 C46B0C48BE5 for ; Sat, 19 Jun 2021 07:56:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE1CD610EA for ; Sat, 19 Jun 2021 07:56:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233963AbhFSH61 (ORCPT ); Sat, 19 Jun 2021 03:58:27 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:33152 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229466AbhFSH60 (ORCPT ); Sat, 19 Jun 2021 03:58:26 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1624089375; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cNstW53zAdTSKjnd/uFTh8EXy2E4aia9C+TcSMNuBas=; b=Y4Zza9RNF6VigLci/ADSaUf4+ygwxRn/7bMN/rCSZje+ZyBSxgRscBgwo+cRPkEhgihh3c A5i9MWuuFoP+1KtABklDV2YsLnart5f45j8QCw4QIy8xeM6bgFQzP7tEf3F1UQMAjjiAlK MHlZjZwaH6hPK1yyEvCN24tkeXlbrNth/bMC4A+4beG2UTwSpCh8mCUZMoCvmjILbh+wiK 7OnM/VN2PWIhMUOWU6o2xT0hClIcYxZ1o9rdw5dJ3JefCrft/n9t2OnOrW7D3cOapKsW1N 641PxYyino6lUNjKLh0Eb37rwpyt8X2mtmFLw6JpVOIViQWeV1cbnkC/pmT0ig== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1624089375; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cNstW53zAdTSKjnd/uFTh8EXy2E4aia9C+TcSMNuBas=; b=bwBA7DmZJN1MBR4lu/rAt+eSH3j5NMDsmCO1p5SPtn9xYETMQSUEHzURcxDfOLhxZSy2hW ugsocUyTTTEFcXCg== To: Juri Lelli , bigeasy@linutronix.de Cc: linux-rt-users@vger.kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org, bristot@redhat.com, Juri Lelli , Anna-Maria Behnsen Subject: Re: [RFC PATCH RT v2 1/2] time/hrtimer: Add PINNED_HARD mode for realtime hrtimers In-Reply-To: <87k0mqeofg.ffs@nanos.tec.linutronix.de> References: <20210616071705.166658-1-juri.lelli@redhat.com> <20210616071705.166658-2-juri.lelli@redhat.com> <87k0mqeofg.ffs@nanos.tec.linutronix.de> Date: Sat, 19 Jun 2021 09:56:14 +0200 Message-ID: <87bl82e19d.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 19 2021 at 01:35, Thomas Gleixner wrote: > The wild west of anything which scratches 'my itch' based on 'my use > case numbers' in Linux ended many years ago and while RT was always a > valuable playground for unthinkable ideas we definitely tried hard not > to accept use case specific hacks wihtout a proper justification that it > makes sense in general. > > So why are you even trying to sell this to me? I wouldn't have been that grumpy if you'd at least checked whether the task is pinned. Still I would have told you that you "fix" it at the wrong place. Why on earth is that nohz heuristic trainwreck not even checking that? It's not a RT problem and it's not a problem restricted to RT tasks either. If a task is pinned then arming the timer on a random other CPU is blatant nonsense independent of the scheduling class. Thanks, tglx