From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 79F0E350A16 for ; Thu, 22 Jan 2026 11:41:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769082074; cv=none; b=jzwUzxDGLT5sp9V3oWM76oh8KUJTbL/2ZWEi1reeFsZ9fHMpV/GQrRnAzynSxyIiXazxssmoh5V3X8A0wJG9euYpO/JY4TlNDFCT4DTUajyMeG3V/1vPah0WwGUqXux2N7FRHCBU9EnI2T0KCugShZhtZvoJOpkkdViKwAPMG2c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769082074; c=relaxed/simple; bh=ht3FAfJxZNL2RczoWtH6cpuTppMFoWPw2TFQbgjPB04=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZrS7I47NyJ9m4tloKpDPcPFRe8MKCDnOceIK9j63lKV6baO6ZkK7YxU/ijNZjlnSGZ1KKJvVz78YEqKOThgFgylED2JcDa/S4TkdxvbRSWw+i5fl2GNHrMb6898lcxgSH62Z0NnKtyI2r7oLsu+GGW5+WYBiUUdJP9btp1cCwJ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=NdqKZc38; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NdqKZc38" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=m0nHDUpy0p+643K/Ig6yIzHwopKfEJURkuDO9DyhjK8=; b=NdqKZc38tPBRoGZkLRAx3J8odz 8ps3Yj4CEdt+j+HzZbiAON+/ONY4sw5auC12LD5vI6UziKSXCjEu6LxVslOljIwUZgKsDYd0HB3Rf uDorc9ldIjj35Zpw+XCjmw/VAnoX/NkYOutNfHJbSpJmnKYcYZ72yamGZ2CeRI8kmjeHd1CgMcH2F WZHF/aLuRQU4od/yc8zMkbleOxbRqqvvkj7c1AtD3VmQFfh+Gy3bwSBvKz4+wxxF1GfXdZzDEuI2t 4qOVdWRVouYJub3cT1QFdILtgWzWO1pAN9P6Suc+OfFrue7YwGHld8tZjCudX7psmOQbXO/9fKXCI 2haLiByg==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vit3Y-00000000GIW-1Sog; Thu, 22 Jan 2026 11:40:57 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 182473007E1; Thu, 22 Jan 2026 12:40:55 +0100 (CET) Date: Thu, 22 Jan 2026 12:40:54 +0100 From: Peter Zijlstra To: Phil Auld Cc: tglx@linutronix.de, arnd@arndb.de, anna-maria@linutronix.de, frederic@kernel.org, luto@kernel.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, oliver.sang@intel.com Subject: Re: [PATCH v2 6/6] sched: Default enable HRTICK Message-ID: <20260122114054.GA3372621@noisy.programming.kicks-ass.net> References: <20260121162010.647043073@infradead.org> <20260121162508.119040984@infradead.org> <20260121222444.GA1370038@pauld.westford.csb> 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: <20260121222444.GA1370038@pauld.westford.csb> On Wed, Jan 21, 2026 at 05:24:44PM -0500, Phil Auld wrote: > Hi Peter, > > On Wed, Jan 21, 2026 at 05:20:16PM +0100 Peter Zijlstra wrote: > > ... for generic entry architectures. This decouples preemption from > > CONFIG_HZ, leaving only the periodic load-balancer and various > > accounting things relying on the tick. > > > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > kernel/sched/features.h | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > --- a/kernel/sched/features.h > > +++ b/kernel/sched/features.h > > @@ -63,8 +63,13 @@ SCHED_FEAT(DELAY_ZERO, true) > > */ > > SCHED_FEAT(WAKEUP_PREEMPTION, true) > > > > +#ifdef TIF_HRTIMER_REARM Arguably this should be CONFIG_GENERIC_ENTRY I suppose > > +SCHED_FEAT(HRTICK, true) > > +SCHED_FEAT(HRTICK_DL, true) > > +#else > > SCHED_FEAT(HRTICK, false) > > SCHED_FEAT(HRTICK_DL, false) > > +#endif > > I maybe be missing something. But the title of this patch > and the above code do not seem to match. You mean it only default enables it for a subset of architectures?