From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 777D418BBB0 for ; Thu, 10 Oct 2024 06:52:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728543159; cv=none; b=F6jClHedm7au4KHB2dgdXgRmi/coa1CUwn4x6rfiXyjg4KDrKoKdv12Kra60P/r5bjNQBbxGbBxKg0RHaYvc9qy09WGLXfwMlDakBTIsW8fDl19gbdeIjXmodT+IiEw9TlnDFOvAE8tbARCAL3/s/c8P147eFof8r3l/ppDWulY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728543159; c=relaxed/simple; bh=/dfysMZNk7ihsP9KTPayANCP3wUJm/wYwVq7TUqQARc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rj5wkmIjVb5o7jjiCjKY7qkLUx6ZW8nuqmftNIc8EqEE464D1oYpS1SJuykAJV0AlaY5dg5o6DJa7kaYhTWtRiK071cAwUyZ8Ei85656BbSxcbjAS7D6FXmTn101qEAULWNZhb8XriOQpjSD89SJzINPVGJzTouhCcZB1iCl9GI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=adiiPF0h; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="adiiPF0h" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=shNRtsMJTnOWIwlG2F9sLUFbdWZ3drtRFcNVsDgF8h0=; b=adiiPF0hQmdpmzaq2Lp/orjK8G 6B0Yi7dhMbPzO9j4C/1OQaRkbEtwYjU7gTrltTS95k5IqmwTq2qimH3GvV7CRXA1FqPQRm56Ma2nk LFSiHQnJzNE1wu0c1gq37S/B+Ao0dspSEX5hVX+alJLO8Cnm0PyTAPrtu8Dc8J4zzeQFp0KvZ9umu ZVZHLezhzfRRHFQhqCjtHSeJLe280fznBlvDJEmsxbGELQIc1REqFTCtkni3cNz8keFdiRK1dNkAL 30JcSS7SL18bfof1Eqw+uyB7JL386kGz0eTTMKptrL3M/JW3uSVxpwJj2dCpmxiK/f3fbEQd5Nt+7 0/2kElZA==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1syn2K-0000000Bk0o-1cgu; Thu, 10 Oct 2024 06:52:36 +0000 Date: Wed, 9 Oct 2024 23:52:36 -0700 From: Christoph Hellwig To: Peter Zijlstra Cc: bigeasy@linutronix.de, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, ankur.a.arora@oracle.com, efault@gmx.de Subject: Re: [PATCH 3/5] sched: Enable PREEMPT_DYNAMIC for PREEMPT_RT Message-ID: References: <20241007074609.447006177@infradead.org> <20241007075055.441622332@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241007075055.441622332@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Oct 07, 2024 at 09:46:12AM +0200, Peter Zijlstra wrote: > In order to enable PREEMPT_DYNAMIC for PREEMPT_RT, remove PREEMPT_RT > from the 'Preemption Model' choice. Strictly speaking PREEMPT_RT is > not a change in how preemption works, but rather it makes a ton more > code preemptible. > > Notably, take away NONE and VOLATILE options for PREEMPT_RT, they make > no sense (but are techincally possible). Should we take away NONE entirely because it is kinda silly? Just a bystander here, but the explosion of different preemption models is a bit silly and not really helpful to users.