From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 C752A26F2A8 for ; Thu, 22 Jan 2026 12:31:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769085094; cv=none; b=mAf29DA0kexMV2uCxY76+Xto3cb4gSeekjv84WMv4dOJZIfR1mIc8Q9OsO52tEXhW26R6fqrfpxolX1FVzGej+nj4NbOxWG4SqdR7kgLTKjuDZtv4rRmZh6cSbbkS2CxTXd6kblcknUKuU4gkl/rE5FNZy1q4uGjh6DxLUU4HBo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769085094; c=relaxed/simple; bh=LXC6IKPKLplR9JmCODhf3y06Rn1muTHIbsZLG2qdj3E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hBS5TRcvoeXkSnePhzukW2hnDlIFX4DAcJf0FSj6IhUQchJnra7hEQ7HTQcjRuQkoF6YD0l8B1VWujnnffaejc+L2bbrn/VqJIy258ucYx31VlZ+VTBVWuYN5l+IWpr4/jc29OXx8/ptZeJLrhQlEbmYIKEmyCC617wyycZ24Xc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=KU7Nacbv; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KU7Nacbv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1769085090; 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=4PP7PMzQjJRqmjIRzeKE4WtUaVus50D3BqqAfMozWCk=; b=KU7NacbvrjOdwjTAw7ka1zfapjLav125f1/MpwkrMlSxvBztQRsqkyNVEKNMhUVxRkK5YM 264Z8kS6WVL5RrGzb3sb/gQze+G1n3N9TYRgmd5xHTX/fKaSgDgKrhDP5A6EtV+FseZYIU L0uOdmqfHaKIM2HmHbna+w78GEgEAHc= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-676-Fu7WBsPYPT6xyAVS2EBJGg-1; Thu, 22 Jan 2026 07:31:26 -0500 X-MC-Unique: Fu7WBsPYPT6xyAVS2EBJGg-1 X-Mimecast-MFC-AGG-ID: Fu7WBsPYPT6xyAVS2EBJGg_1769085084 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 145F918003FD; Thu, 22 Jan 2026 12:31:24 +0000 (UTC) Received: from pauld.westford.csb (unknown [10.22.80.156]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 77CC91800993; Thu, 22 Jan 2026 12:31:19 +0000 (UTC) Date: Thu, 22 Jan 2026 07:31:17 -0500 From: Phil Auld To: Peter Zijlstra 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: <20260122123117.GA1389473@pauld.westford.csb> References: <20260121162010.647043073@infradead.org> <20260121162508.119040984@infradead.org> <20260121222444.GA1370038@pauld.westford.csb> <20260122114054.GA3372621@noisy.programming.kicks-ass.net> 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: <20260122114054.GA3372621@noisy.programming.kicks-ass.net> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On Thu, Jan 22, 2026 at 12:40:54PM +0100 Peter Zijlstra wrote: > 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? > Nope, I mean I can't read... nevermind. Cheers, Phil --