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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB984CA0EC3 for ; Tue, 12 Sep 2023 12:25:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235142AbjILMZr (ORCPT ); Tue, 12 Sep 2023 08:25:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235153AbjILMZe (ORCPT ); Tue, 12 Sep 2023 08:25:34 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 972AC10D5 for ; Tue, 12 Sep 2023 05:24:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694521484; 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=wpmb0UDWOEHxEWVSzY4F9Zon4yh+xezV1w7VKzgYnYQ=; b=W5Vrz0psA41wVYKcqlBfGyL1PSLQE9O8N1HJtG/eGcvl3AJkLCy0Ka2O5PbTkqHqQ35zFd pFr5ip3f0bVkcxbNr5J8HPymQoMzuXoCeljSD9Aq9a09bzo+Ny9JuiHwG7sN+5WQ3gF6ux JHiafmGWvVhNfGx95JihR8KTf34BRUE= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-170-tisFaeRwOLyLW1avEpqfOA-1; Tue, 12 Sep 2023 08:24:41 -0400 X-MC-Unique: tisFaeRwOLyLW1avEpqfOA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2EDF71C06E0A; Tue, 12 Sep 2023 12:24:40 +0000 (UTC) Received: from lorien.usersys.redhat.com (unknown [10.22.17.68]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CBB282026D4B; Tue, 12 Sep 2023 12:24:38 +0000 (UTC) Date: Tue, 12 Sep 2023 08:24:37 -0400 From: Phil Auld To: Peter Zijlstra Cc: Ankur Arora , Linus Torvalds , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, rostedt@goodmis.org, tglx@linutronix.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com Subject: Re: [PATCH v2 7/9] sched: define TIF_ALLOW_RESCHED Message-ID: <20230912122437.GA51582@lorien.usersys.redhat.com> References: <20230908070258.GA19320@noisy.programming.kicks-ass.net> <87zg1v3xxh.fsf@oracle.com> <87edj64rj1.fsf@oracle.com> <87zg1u1h5t.fsf@oracle.com> <20230911150410.GC9098@noisy.programming.kicks-ass.net> <87h6o01w1a.fsf@oracle.com> <20230912082606.GB35261@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230912082606.GB35261@noisy.programming.kicks-ass.net> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 12, 2023 at 10:26:06AM +0200 Peter Zijlstra wrote: > On Mon, Sep 11, 2023 at 10:04:17AM -0700, Ankur Arora wrote: > > > > How expensive would be always having PREEMPT_COUNT=y? > > Effectively I think that is true today. At the very least Debian and > SuSE (I can't find a RHEL .config in a hurry but I would think they too) > ship with PREEMPT_DYNAMIC=y. > Yes, RHEL too. Cheers, Phil --