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 3A495C38145 for ; Tue, 6 Sep 2022 23:43:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229564AbiIFXnO (ORCPT ); Tue, 6 Sep 2022 19:43:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50978 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbiIFXnL (ORCPT ); Tue, 6 Sep 2022 19:43:11 -0400 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34E1C868A3 for ; Tue, 6 Sep 2022 16:43:10 -0700 (PDT) Received: by mail-pl1-x644.google.com with SMTP id iw17so6165926plb.0 for ; Tue, 06 Sep 2022 16:43:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date; bh=/qu2n9BlVn7Hcbe1BO172p4KxMySv9JPsd+DqpGVTAU=; b=bMZjQCiygEcwxhJnXa9R9YZP7JXsM125Q0KenhaZn15zQhU9FrF7bsgd4LBLa7mZsr D9dsj3DLjoyN9yufdg1WnDe4N4JXU3qYJbPLXqxfSVBvmTIvTdJvW627WeWHvJQo6h7p Bvff4fbhgquyQh892WIxr5eqJrLRtnb/txmWbR+P/YfnqcwSGx3rROaJpsFGJrGr/man K/JT/ZzhW54VgS+b8c+NL7VFwQ13V8vOudEwGyKJI63vhrjLBFklscwuEVrQAEL8e+Xk aTZRxs6FchWNO7q0Xzv9hHZIw+Wy56xYLXyrkpP7vwhpjvOYfrtOB3JyII25C9y98Yfu aQTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date; bh=/qu2n9BlVn7Hcbe1BO172p4KxMySv9JPsd+DqpGVTAU=; b=YehVQpPRS8K3+pEZzcvrnSDPseDJOfTqG+m3SFAi2Qbbjvq1/qjVZ/9YSIRO0QgJeW zCsNFayxsjPGJToJKwVY605uNeQaJuoI2QwqYTlcgeY/SOdkqaLrDMafSkeEEe0Sq65/ KcSpuWyBaf1I8UGsW+Cg3vO8dpV/WHrwpO3Sz5aQ46H+kIUmd+rbHZ+VGBeOKehxIKF3 pnPCB0Yl/vZOtiujAKLMkxfazpkdUVnj9vE25OZM/oQ88qe5XzOWZt3A7Ibb2/wdi3q9 RTbsBOC57f8XnmNsMm9xjec5a2+NCX0V/RWKMoeZN4J2BTGYxE45EKCb/OHTjHZaPZqo jPSg== X-Gm-Message-State: ACgBeo1UPQ50kzr04dLYVMvkjuSZHSwJLtLMQIuLLcIJc3GBTNXr+1+W wkHkcFQjQKaW4ng0cBrLzPIG0cpK9lMS5iBB X-Google-Smtp-Source: AA6agR6e6bJhlmKpwxoAHPb43L8BCb+CSDaRKxAwiDg+TlnwBrniT4OcUn1qUKbTLCwSxNbTeAxMFw== X-Received: by 2002:a17:902:ebc8:b0:172:549d:e392 with SMTP id p8-20020a170902ebc800b00172549de392mr1055168plg.141.1662507789398; Tue, 06 Sep 2022 16:43:09 -0700 (PDT) Received: from sophie ([169.150.203.49]) by smtp.gmail.com with ESMTPSA id g1-20020a17090a708100b001fbb0f0b00fsm13269789pjk.35.2022.09.06.16.43.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Sep 2022 16:43:08 -0700 (PDT) Date: Tue, 6 Sep 2022 18:43:06 -0500 From: Rebecca Mckeever To: David Hildenbrand Cc: Mike Rapoport , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/4] memblock tests: add simulation of physical memory with multiple NUMA nodes Message-ID: <20220906234306.GA4053@sophie> References: <49b96ce88dece5b394d5dd4332c1572da917b30a.1662264560.git.remckee0@gmail.com> 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 Tue, Sep 06, 2022 at 03:17:46PM +0200, David Hildenbrand wrote: > On 04.09.22 06:21, Rebecca Mckeever wrote: > > Add function setup_numa_memblock() for setting up a memory layout with > > multiple NUMA nodes in a previously allocated dummy physical memory. > > This function can be used in place of setup_memblock() in tests that need > > to simulate a NUMA system. > > > > setup_numa_memblock(): > > - allows for setting up a memory layout by specifying the fraction of > > MEM_SIZE in each node > > > > Set CONFIG_NODES_SHIFT to 4 when building with NUMA=1 to allow for up to > > 16 NUMA nodes. > > > > Signed-off-by: Rebecca Mckeever > > --- > > .../testing/memblock/scripts/Makefile.include | 2 +- > > tools/testing/memblock/tests/common.c | 29 +++++++++++++++++++ > > tools/testing/memblock/tests/common.h | 4 ++- > > 3 files changed, 33 insertions(+), 2 deletions(-) > > > > diff --git a/tools/testing/memblock/scripts/Makefile.include b/tools/testing/memblock/scripts/Makefile.include > > index aa6d82d56a23..998281723590 100644 > > --- a/tools/testing/memblock/scripts/Makefile.include > > +++ b/tools/testing/memblock/scripts/Makefile.include > > @@ -3,7 +3,7 @@ > > # Simulate CONFIG_NUMA=y > > ifeq ($(NUMA), 1) > > - CFLAGS += -D CONFIG_NUMA > > + CFLAGS += -D CONFIG_NUMA -D CONFIG_NODES_SHIFT=4 > > endif > > # Use 32 bit physical addresses. > > diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c > > index eec6901081af..b6110df21b2a 100644 > > --- a/tools/testing/memblock/tests/common.c > > +++ b/tools/testing/memblock/tests/common.c > > @@ -72,6 +72,35 @@ void setup_memblock(void) > > fill_memblock(); > > } > > +/** > > + * setup_numa_memblock: > > + * Set up a memory layout with multiple NUMA nodes in a previously allocated > > + * dummy physical memory. > > + * @nodes: an array containing the denominators of the fractions of MEM_SIZE > > + * contained in each node (e.g., if nodes[0] = SZ_8, node 0 will > > + * contain 1/8th of MEM_SIZE) > > + * > > + * The nids will be set to 0 through NUMA_NODES - 1. > > + */ > > +void setup_numa_memblock(const phys_addr_t nodes[]) > > +{ > > + phys_addr_t base; > > + int flags; > > + > > + reset_memblock_regions(); > > + base = (phys_addr_t)memory_block.base; > > + flags = (movable_node_is_enabled()) ? MEMBLOCK_NONE : MEMBLOCK_HOTPLUG; > > + > > + for (int i = 0; i < NUMA_NODES; i++) { > > + assert(nodes[i] <= MEM_SIZE && nodes[i] > 0); > > I think it would be even easier to get if this would just be a fraction. > E.g., instead of "1/8 * MEM_SIZE" just "1/8". All values have to add up to > 1. > > ... but then we'd have to mess with floats eventually, so I guess this makes > it easier to handle these fractions. > > > We could use "int" and simply specify the fraction in percent, like > > nodes[0] = 50; > nodes[1] = 25; > nodes[2] = 25; > > and everything has to add up to 100. > This would still be a float for 1/8th (12.5) and 1/16th (6.25). What if it was the "percent" of 256 (i.e., 0x100)? > > > + phys_addr_t size = MEM_SIZE / nodes[i]; > > > Hmmm, assuming a single node with "MEM_SIZE", we would get size=1. > For a single node of MEM_SIZE, nodes[0] would be 1. > Shouldn't this be "size = nodes[i]" > > ? No, not with the current implementation. The nodes array stores the denominator of the fraction that will be multiplied by MEM_SIZE to determine the size of that node (the numerator is always 1). So if the size of the node should be 1/8 * MEM_SIZE, the nodes array just stores the 8. I think the name of the array is misleading. Do you have any suggestions for a better name? > > -- > Thanks, > > David / dhildenb > Thanks, Rebecca