From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 784111A316B for ; Wed, 5 Mar 2025 17:15:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741194903; cv=none; b=Arq2pVzATbRh++CV8k85/zFIPz4d/NDWkCAaEcbtbk/qkkoaK98wxikyMjs4DFFaOS5O31E1qr04IIKHVYKjdniZJxgqCHkrKV+VEjFeKrlo7X++Rw9BE1mCEV8wHH9B36UTJJ5B5MtEUZ8I0QWduN9FBW6rU0KReLfjZJeR/FA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741194903; c=relaxed/simple; bh=NRyIecO563t4ImdsW1jXI5+TuemGsKbjSkF61FbeBh0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QVhCgjlj1lyX1uRKs36sTMlV0r13GBP93/2JkNsd0emPtVA4bR9iYsqAcsBbTi8l5qeR2AsCPf033GNsw+u54kdvwzKZ3Fzod7UHYf88jKiOszbdXV7ILxP/4UQobff4lD9sxDDSFWo/lsY3Hoi5vwxqDCSLYUhKKE9kzzUtbs8= 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=D6buxw3T; arc=none smtp.client-ip=170.10.129.124 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="D6buxw3T" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741194900; 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=Fq/qFJHlaiGnCpFW2MwqaXdlBcGCWunAFoUN3TsxIqk=; b=D6buxw3Tl15ICdcGCCP8iNH13QLv1EFC2n0qIiIvlYy3BnTZ7MXJEB7SmGgwFfGmCaL819 iSZuFUnXCaN/pUibvqlO8SSzLkQPnzK55SxGuPu1uEfsCKobDxaG4tm1URuBdH2nKJXTQU yAvLiZH0G++GDZsuIZhJG+GHhK7Sz7E= Received: from mx-prod-mc-08.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-641-RCaTDZ4vN1KprYPjCjOS4A-1; Wed, 05 Mar 2025 12:14:47 -0500 X-MC-Unique: RCaTDZ4vN1KprYPjCjOS4A-1 X-Mimecast-MFC-AGG-ID: RCaTDZ4vN1KprYPjCjOS4A_1741194886 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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A45EE180AF4E; Wed, 5 Mar 2025 17:14:45 +0000 (UTC) Received: from pauld.westford.csb (unknown [10.22.65.55]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B6EE3300019E; Wed, 5 Mar 2025 17:14:43 +0000 (UTC) Date: Wed, 5 Mar 2025 12:14:41 -0500 From: Phil Auld To: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Juri Lelli , Waiman Long , Vishal Chourasia , Vineeth Reddy Subject: Re: [PATCH v2] sched/isolation: Make use of more than one housekeeping cpu Message-ID: <20250305171441.GC51446@pauld.westford.csb> References: <20250218184618.1331715-1-pauld@redhat.com> 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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On Tue, Mar 04, 2025 at 02:24:19PM +0100 Frederic Weisbecker wrote: > Le Tue, Feb 18, 2025 at 06:46:18PM +0000, Phil Auld a écrit : > > The exising code uses housekeeping_any_cpu() to select a cpu for > > a given housekeeping task. However, this often ends up calling > > cpumask_any_and() which is defined as cpumask_first_and() which has > > the effect of alyways using the first cpu among those available. > > > > The same applies when multiple NUMA nodes are involved. In that > > case the first cpu in the local node is chosen which does provide > > a bit of spreading but with multiple HK cpus per node the same > > issues arise. > > > > We have numerous cases where a single HK cpu just cannot keep up > > and the remote_tick warning fires. It also can lead to the other > > things (orchastration sw, HA keepalives etc) on the HK cpus getting > > starved which leads to other issues. In these cases we recommend > > increasing the number of HK cpus. But... that only helps the > > userspace tasks somewhat. It does not help the actual housekeeping > > part. > > > > Spread the HK work out by having housekeeping_any_cpu() and > > sched_numa_find_closest() use cpumask_any_and_distribute() > > instead of cpumask_any_and(). > > > > Signed-off-by: Phil Auld > > Reviewed-by: Waiman Long > > Cc: Peter Zijlstra > > Cc: Juri Lelli > > Cc: Frederic Weisbecker > > Cc: Waiman Long > > Cc: linux-kernel@vger.kernel.org > > Link: https://lore.kernel.org/lkml/20250211141437.GA349314@pauld.westford.csb/ > > Acked-by: Frederic Weisbecker > Thanks Frederic! Anyone with commit powers willing to pick this up? Thanks, Phil --