From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 AB85A1AE876 for ; Wed, 26 Mar 2025 10:46:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742986008; cv=none; b=h0I5EeOpxfES4DfTeT4tqZkmMaDYt/2dZ/nZcIYzdN227JcKt4tdYpA+rYZ/GHJQago6RXR2zrKLTRAIF/UnRfdOE3n1ohbwzl7Jj0jg+KE6Hgnxin0RHRWLTLG419bqVLsa1+sp6Zm+iftRSMVM1NtpmS2U8Ke/FywdHIZKYvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742986008; c=relaxed/simple; bh=WX4cqTlZEbs9Hwg4nddBqQtyhY2nnkhpxJz/QIbatfY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NP1mX+ZVm1aZrpG+cyPA4e8/hNcQ2ArHmjJ7I844+opHywT4QZRdsnUVeVht3tZp6HqQHzfzy6hSk5ak7RxLWzev4v0FCzqqa1AzzykGayza0SCRKxjmJ+jWLGQhe4iTWTlLgj3kV1YLXRoUfdoPhfHF8RPJKYGrglcBzMtWPJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=IuLIAG44; arc=none smtp.client-ip=90.155.50.34 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=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="IuLIAG44" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=64NlIFTX6igdIKyqbO9/7Y2I1xjU9JuHdqRdG30MxD0=; b=IuLIAG44znVPcN+VS/AZf2GTqR kBcUc8USFFgteOfJCzQCRuZTgjFhq2INL0pr5K3ccjqtQqp4KdagsH8ZfZWgyUMn3vCMWxZ7ROU2U HBylHiq0+86vWymdu3Lm37RpNyRLroS0GAFjYrDUBkCAh4e0w99IhHUTOyVplp4z59H0KZLPV/h+q 5MeqAnYg9VE9cZmWfBoysoLoYw3ztDxikzlrEQLVtPXiIIuphWlb/54s2pJhtoqFBgExMbS0ytuo6 L4tnrq8DvPk0ZUU9KCi0zl7esiS5d1//FxpGMH8QtSOR/gyfqYddDHzYnI6/Rnml0c+TyaYE/mZRV 5f80Lcpg==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.1 #2 (Red Hat Linux)) id 1txOHD-0000000HPVh-45ZY; Wed, 26 Mar 2025 10:46:28 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 4247F3003C4; Wed, 26 Mar 2025 11:46:27 +0100 (CET) Date: Wed, 26 Mar 2025 11:46:27 +0100 From: Peter Zijlstra To: "Chen, Yu C" Cc: 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, tim.c.chen@linux.intel.com, tglx@linutronix.de, len.brown@intel.com, gautham.shenoy@amd.com, mingo@kernel.org, kprateek.nayak@amd.com, yu.chen.surf@foxmail.com Subject: Re: [RFC][PATCH] sched: Cache aware load-balancing Message-ID: <20250326104627.GC12071@noisy.programming.kicks-ass.net> References: <20250325120952.GJ36322@noisy.programming.kicks-ass.net> <4cd8ba54-8b9e-4563-8fbc-1d6cd6699e81@intel.com> <20250326093841.GC25239@noisy.programming.kicks-ass.net> <20250326102553.GA12071@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: <20250326102553.GA12071@noisy.programming.kicks-ass.net> On Wed, Mar 26, 2025 at 11:25:53AM +0100, Peter Zijlstra wrote: > On Wed, Mar 26, 2025 at 10:38:41AM +0100, Peter Zijlstra wrote: > > > Nah, the saner thing to do is to preserve the topology averages and look > > at those instead of the per-cpu values. > > > > Eg. have task_cache_work() compute and store averages in the > > sched_domain structure and then use those. > > A little something like so perhaps ? Oh urgh, ignore all that, I'm an idiot. The numbers are per process, can't stick them in global structures. I remember going through all this before :-/ Its just so very tempting since its the right structure and everything, but we need it per process :-(