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 2480FC001B0 for ; Tue, 8 Aug 2023 16:57:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232745AbjHHQ5U (ORCPT ); Tue, 8 Aug 2023 12:57:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233245AbjHHQ4n (ORCPT ); Tue, 8 Aug 2023 12:56:43 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15D2BA286 for ; Tue, 8 Aug 2023 08:59:55 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 837582031A; Tue, 8 Aug 2023 09:59:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1691488750; h=from:from:reply-to: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=tv+ZghxAfCxLOqZPv3CyvrkPVy+sfVKBpO+7ooghzNk=; b=zmsfjY6MRT3flhWagijVnhr8jPGbN3zAgkpJOfcsB4bcaAR7mhSQRwNNq6n+ky5zdSzqQ+ yumoGduk17gLNstsul9Ieau2UP+QMgym7MBEws4DCxT2VNx4275QZxd97z80ftLG+SsHTr GBn20N5Wlc8XSE3UfXVhtUHkLvb2BdQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1691488750; h=from:from:reply-to: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=tv+ZghxAfCxLOqZPv3CyvrkPVy+sfVKBpO+7ooghzNk=; b=KWaTPpkpsC9NB1tTzYPgMjlapotcodSopYQoVZ0P7r4c7NN+Xny4dVC8VbjSvYXtiWj2YY iopgwM1rVG4IlICw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 38A2113451; Tue, 8 Aug 2023 09:59:10 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id pPQqDe4R0mT/JwAAMHmgww (envelope-from ); Tue, 08 Aug 2023 09:59:10 +0000 Message-ID: Date: Tue, 8 Aug 2023 11:59:09 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.14.0 Subject: Re: [RFC 2/2] mm/slub: prefer NUMA locality over slight memory saving on NUMA machines Content-Language: en-US To: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Christoph Lameter , Pekka Enberg , Joonsoo Kim , David Rientjes , Andrew Morton , Roman Gushchin , Feng Tang , "Sang, Oliver" , Jay Patel , Binder Makin , aneesh.kumar@linux.ibm.com, tsahu@linux.ibm.com, piyushs@linux.ibm.com, fengwei.yin@intel.com, ying.huang@intel.com, lkp , "oe-lkp@lists.linux.dev" , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20230723190906.4082646-1-42.hyeyoo@gmail.com> <20230723190906.4082646-3-42.hyeyoo@gmail.com> <1f88aff2-8027-1020-71b2-6a6528f82207@suse.cz> From: Vlastimil Babka In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/7/23 10:39, Hyeonggon Yoo wrote: > On Thu, Aug 3, 2023 at 11:54 PM Vlastimil Babka wrote: >> > > Thank you for looking at it! > > Yeah, it was a PoC for what I thought "oh, it might be useful" > and definitely I will try to measure it. > >> We could also postpone this until we have tried the percpu arrays >> improvements discussed at LSF/MM. > > Possibly, but can you please share your plans/opinions on it? Here's the very first attempt :) https://lore.kernel.org/linux-mm/20230808095342.12637-7-vbabka@suse.cz/ > I think one possible way is simply to allow the cpu freelist to be > mixed by objects from different slabs I didn't try that way, might be much trickier than it looks. > if we want to minimize changes, Or introduce a per cpu array similar > to what SLAB does now. Yes. > And one thing I'm having difficulty understanding is - what is the > mind behind/or impact of managing objects > on a slab basis, other than avoiding array queues in 2007? "The mind" is Christoph's so I'll leave that question to him :)