From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8959EB64D9 for ; Wed, 12 Jul 2023 12:23:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232644AbjGLMXa (ORCPT ); Wed, 12 Jul 2023 08:23:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231127AbjGLMX2 (ORCPT ); Wed, 12 Jul 2023 08:23:28 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56B03B0 for ; Wed, 12 Jul 2023 05:23:26 -0700 (PDT) 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=Fb9uUBAWeKUKSGvwrV56h7znLSTMuzoCO7lSOEllzLs=; b=oxiU/FySZXg225dH8rympKBP3a qFHVptr3oS/U3eHP2p9D12Jp1oCfqaTWjNjuFU5XkZqNJphGVKGTIS/DuIpkZQ7XCGNtYvKGNRs2L rqPmhi9GinyVQzH7G/IF7qt3UWRSsaIkp5lGv7ymIlK2sAjibauBFff4F2k3t5t3CuzVH61+Zgrca 5kNV3n5avriGTz9BPO1MWUeVojSFsA3Es83gSjSuynhipn1WveH3UY+XEZUa4bQKLCnFk82hoh96E gCu7yBXp4q2u32Wm710wmXzfObQuP+fiEf5hycEMA9zeomF1swJyIYm2Jw1UFQIEMK3SusCfpOOd8 lEl7puYQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qJYru-00Gfpp-GQ; Wed, 12 Jul 2023 12:22:54 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 7E46730056F; Wed, 12 Jul 2023 14:22:52 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 5EC6C2CA56983; Wed, 12 Jul 2023 14:22:52 +0200 (CEST) Date: Wed, 12 Jul 2023 14:22:52 +0200 From: Peter Zijlstra To: "Gautham R. Shenoy" Cc: David Vernet , linux-kernel@vger.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, bristot@redhat.com, vschneid@redhat.com, kprateek.nayak@amd.com, aaron.lu@intel.com, clm@meta.com, tj@kernel.org, roman.gushchin@linux.dev, kernel-team@meta.com Subject: Re: [PATCH v2 6/7] sched: Shard per-LLC shared runqueues Message-ID: <20230712122252.GG3100107@hirez.programming.kicks-ass.net> References: <20230710200342.358255-1-void@manifault.com> <20230710200342.358255-7-void@manifault.com> <20230711104958.GG3062772@hirez.programming.kicks-ass.net> <20230711195757.GD389526@maniforge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 12, 2023 at 03:36:27PM +0530, Gautham R. Shenoy wrote: > On some Intel servers, it is possible that the CPU numbers are > interleaved across the two sockets. On my 2 socket, 32Cores per socket > Ice Lake Server, all the even numbered CPUs are in one socket and all > the odd numbered CPUs in the other socket. > > The SMT siblings are {0,64}, {2, 66}, .... on one socket and {1, 65}, > {3, 67}, .. on the other. Yeah, Intel SMT enumeration is a mess. There's a random mix of {n,n+1} and {0..n-1} {n..2n-1}. And then there's the fun hybrid stuff. Those appear to do {n,n+1} for the big cores and then continue with the small cores in a dense set. My 8+8 ADL, has: {0,1} {2,3} {4,5} {6,7} {8,9} {10,11} {12,13} {14,15} {16} {17} {18} {19} {20} {21} {22} {23} I suspect it might be easier to re-number the whole show at boot to fit a sane pattern rather than trying to match the various random garbage gifted to us by the BIOS. I wouldn't worry about it too much at this point.