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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79A37C433EF for ; Wed, 29 Sep 2021 19:24:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CBCB61526 for ; Wed, 29 Sep 2021 19:24:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345485AbhI2TZy (ORCPT ); Wed, 29 Sep 2021 15:25:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:52020 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343505AbhI2TZx (ORCPT ); Wed, 29 Sep 2021 15:25:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D669F6140F; Wed, 29 Sep 2021 19:24:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632943452; bh=Kic1xJl340EDGWe45l8iOlr2pQS1CGNbWFMeOBeCVnQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IV9s+ltdhsqghIwkv47ivP4VliZE95ZjYph5zm7PrF+feipDFsaYdAfYHrYHP+o0A 4XjDdKqz5o9ZKLmYkZF2bJmEqO0FE8mdOU9FAaDQfOCnPReQrWPkMvs28GQdMxaXU8 MB38pj16HImpN4iSocIU0nRR7gU9Niv5fMZTmXK39CczqigP9s9jSQ+kFJ7d3seBFA K35UkTtgv8ZKKFtE7b+ljU8gW91H6CA6DHe8dIcv1JCHku47lSJlc8EDC5/kuwIynw l6VM7HOhMvDgT8DAqopy6fodKqmpWD1AjYNKqNrn53dAP2iqyB+SeBK3/3XquBLVAE J/Kno9ZVXtRCw== Date: Wed, 29 Sep 2021 12:24:06 -0700 From: Nathan Chancellor To: Zhenguo Yao Cc: mike.kravetz@oracle.com, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, corbet@lwn.net, rppt@kernel.org, akpm@linux-foundation.org, yaozhenguo@jd.com, willy@infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev Subject: Re: [PATCH v7] hugetlbfs: Extend the definition of hugepages parameter to support node allocation Message-ID: References: <20210927104149.46884-1-yaozhenguo1@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210927104149.46884-1-yaozhenguo1@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Mon, Sep 27, 2021 at 06:41:49PM +0800, Zhenguo Yao wrote: > We can specify the number of hugepages to allocate at boot. But the > hugepages is balanced in all nodes at present. In some scenarios, > we only need hugepages in one node. For example: DPDK needs hugepages > which are in the same node as NIC. if DPDK needs four hugepages of 1G > size in node1 and system has 16 numa nodes. We must reserve 64 hugepages > in kernel cmdline. But, only four hugepages are used. The others should > be free after boot. If the system memory is low(for example: 64G), it will > be an impossible task. So, Extending hugepages parameter to support > specifying hugepages at a specific node. > For example add following parameter: > > hugepagesz=1G hugepages=0:1,1:3 > > It will allocate 1 hugepage in node0 and 3 hugepages in node1. > > Signed-off-by: Zhenguo Yao > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 95dc7b83381f..ca00676a1bdd 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -66,6 +66,7 @@ static struct hstate * __initdata parsed_hstate; > static unsigned long __initdata default_hstate_max_huge_pages; > static bool __initdata parsed_valid_hugepagesz = true; > static bool __initdata parsed_default_hugepagesz; > +static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata; > > /* > * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, > @@ -2868,33 +2869,41 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, > return ERR_PTR(-ENOSPC); > } > > -int alloc_bootmem_huge_page(struct hstate *h) > +int alloc_bootmem_huge_page(struct hstate *h, int nid) > __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); > -int __alloc_bootmem_huge_page(struct hstate *h) > +int __alloc_bootmem_huge_page(struct hstate *h, int nid) > { > struct huge_bootmem_page *m; > int nr_nodes, node; > > + if (nid >= nr_online_nodes) > + return 0; > + /* do node specific alloc */ > + if (nid != NUMA_NO_NODE) { > + m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), > + 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); > + if (m) > + goto found; > + else > + return 0; > + } > + /* do all node balanced alloc */ > for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { > - void *addr; > - > - addr = memblock_alloc_try_nid_raw( > + m = memblock_alloc_try_nid_raw( > huge_page_size(h), huge_page_size(h), > 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); > - if (addr) { > - /* > - * Use the beginning of the huge page to store the > - * huge_bootmem_page struct (until gather_bootmem > - * puts them into the mem_map). > - */ > - m = addr; > + /* > + * Use the beginning of the huge page to store the > + * huge_bootmem_page struct (until gather_bootmem > + * puts them into the mem_map). > + */ > + if (m) > goto found; > - } > + else > + return 0; > } > - return 0; > > found: > - BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); > /* Put them into a private list first because mem_map is not up yet */ > INIT_LIST_HEAD(&m->list); > list_add(&m->list, &huge_boot_pages); This hunk causes a clang warning now: mm/hugetlb.c:2957:33: error: variable 'm' is used uninitialized whenever '&&' condition is false [-Werror,-Wsometimes-uninitialized] for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/hugetlb.c:1254:3: note: expanded from macro 'for_each_node_mask_to_alloc' nr_nodes > 0 && \ ^~~~~~~~~~~~ mm/hugetlb.c:2974:18: note: uninitialized use occurs here INIT_LIST_HEAD(&m->list); ^ mm/hugetlb.c:2957:33: note: remove the '&&' if its condition is always true for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { ^ mm/hugetlb.c:2942:29: note: initialize the variable 'm' to silence this warning struct huge_bootmem_page *m; ^ = NULL 1 error generated. I am not sure if it is possible for nr_nodes to be 0 right out of the gate so might be a false positive? Cheers, Nathan