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 8546C1D1F6D for ; Fri, 6 Sep 2024 16:31:39 +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=1725640301; cv=none; b=S0Hdf/UezV+sxt4HoHsiZXJdhFht39yGY1fnDMP8s/4oZ2rPCN2Fa6I0NP9DAs1H+5T11GqmShWUm+KBnyoeYUbz6rqWeCC9mMcgUd1Lmsyxt3kFb41FVQhBJGxjbQOPV+zGf4sDvjxGL398FsFUm9fVYNRMBP+jD0N6DqIeOVU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725640301; c=relaxed/simple; bh=KZ79ji41UrPP4ECVC48yOmyNPfE5rwmoulUj0pcs0LA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Y3klxp+rbGjlzPF55VhQqtrvacRRGPVQxULbKw1o2Xdjd7KNej7+taXtE2RHJuqZJkmF2TYA8GiuMBtad/MlTFMxUaI6WglOoRznRZlv31Z3LVU0ypYF1d+4gLDeMleWDlitpMaNNeiFl6Vsnz1L+Ww5NB02V1QJjBqwCUq5/eM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=iCUw0ocA; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="iCUw0ocA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1725640298; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=G522UJp7KiCHGPaSCy1MevxPOkpCIpCMoVNa9BO+Pjw=; b=iCUw0ocALQaPOVt7fMZr5ZaUHZwp6vo+nvtB44/OYpkyO1Yej7B2h9upEvigCaV1HL9jsE lNl1i0CR2LuvHDPwAwGyIkQgXQLMzPYRWw1ZadrwlBkRCjRclWjyhhGJBju4rgkbitA35e 8dxpksu2kG7pYfNlppBCXH19DIy0b+k= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-390-ZbzpyhzwPGGW4gInO9rZeQ-1; Fri, 06 Sep 2024 12:31:33 -0400 X-MC-Unique: ZbzpyhzwPGGW4gInO9rZeQ-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 924DF193F078; Fri, 6 Sep 2024 16:31:31 +0000 (UTC) Received: from [10.2.16.252] (unknown [10.2.16.252]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8A5D53000238; Fri, 6 Sep 2024 16:31:28 +0000 (UTC) Message-ID: Date: Fri, 6 Sep 2024 12:31:27 -0400 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] sched/fair: Use HK_TYPE_SCHED housekeeping CPUs To: Frederic Weisbecker Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org References: <20240818234520.90186-1-longman@redhat.com> <20240818234520.90186-3-longman@redhat.com> <70e5a6f3-1cff-46c9-af34-75664961eae2@redhat.com> Content-Language: en-US From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On 9/6/24 08:53, Frederic Weisbecker wrote: > Le Wed, Sep 04, 2024 at 10:54:15AM -0400, Waiman Long a écrit : >> On 9/3/24 09:53, Waiman Long wrote: >>> On 9/3/24 09:12, Frederic Weisbecker wrote: >>>> Le Sun, Aug 18, 2024 at 07:45:19PM -0400, Waiman Long a écrit : >>>>> As the previous commit has enabled the setting of HK_TYPE_SCHED >>>>> housekeeping CPUs in nohz_full setup, we can now use the more aptly >>>>> named HK_TYPE_SCHED housekeeping CPUs instead of HK_TYPE_MISC. >>>>> >>>>> Signed-off-by: Waiman Long >>>> Can we instead merge HK_FLAG_TICK, HK_FLAG_WQ, HK_FLAG_TIMER, >>>> HK_FLAG_RCU, >>>> HK_FLAG_MISC and HK_FLAG_KTHREAD into a single >>>> HK_FLAG_KERNEL_NOISE / HK_TYPE_KERNEL_NOISE ? >>> Sure. I am open to new name as I am not good on that. >>> HK_FLAG_KERNEL_NOISE does make sense. >> I can't merge HK_FLAG_TICK just yet as it can be independently set by using >> isolcpus which can set just HK_TYPE_TICK, HK_TYPE_DOMAIN or >> HK_TYPE_MANAGED_IRQ. That is the reason why they are still separate. > Ah I think we really need to unify behaviours of isolcpus=nohz and nohz_full= > > diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c > index 5891e715f00d..9bc8fbf326cc 100644 > --- a/kernel/sched/isolation.c > +++ b/kernel/sched/isolation.c > @@ -212,7 +212,8 @@ static int __init housekeeping_isolcpus_setup(char *str) > while (isalpha(*str)) { > if (!strncmp(str, "nohz,", 5)) { > str += 5; > - flags |= HK_FLAG_TICK; > + flags |= HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | > + HK_FLAG_MISC | HK_FLAG_KTHREAD; > continue; > } I am not against it, but it is a change in userspace behavior. How about we introduce "isolcpus=nohz_full" option that essentially combines isolcpus and nohz_full in one option? That can be a separate patch. Cheers, Longman