From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 9C8A16B0003 for ; Thu, 7 Jun 2018 06:49:18 -0400 (EDT) Received: by mail-pf0-f200.google.com with SMTP id s16-v6so4439249pfm.1 for ; Thu, 07 Jun 2018 03:49:18 -0700 (PDT) Received: from huawei.com (szxga05-in.huawei.com. [45.249.212.191]) by mx.google.com with ESMTPS id ca5-v6si19195870plb.143.2018.06.07.03.49.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Jun 2018 03:49:17 -0700 (PDT) Date: Thu, 7 Jun 2018 11:48:51 +0100 From: Jonathan Cameron Subject: Re: [PATCH 1/4] mm/memory_hotplug: Make add_memory_resource use __try_online_node Message-ID: <20180607114851.00005bd8@huawei.com> In-Reply-To: <20180601125321.30652-2-osalvador@techadventures.net> References: <20180601125321.30652-1-osalvador@techadventures.net> <20180601125321.30652-2-osalvador@techadventures.net> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: osalvador@techadventures.net Cc: akpm@linux-foundation.org, mhocko@suse.com, vbabka@suse.cz, pasha.tatashin@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador On Fri, 1 Jun 2018 14:53:18 +0200 wrote: > From: Oscar Salvador > > add_memory_resource() contains code to allocate a new node in case > it is necessary. > Since try_online_node() also hast some code for this purpose, > let us make use of that and remove duplicate code. > > This introduces __try_online_node(), which is called by add_memory_resource() > and try_online_node(). > __try_online_node() has two new parameters, start_addr of the node, > and if the node should be onlined and registered right away. > This is always wanted if we are calling from do_cpu_up(), but not > when we are calling from memhotplug code. > Nothing changes from the point of view of the users of try_online_node(), > since try_online_node passes start_addr=0 and online_node=true to > __try_online_node(). > Trivial whitespace issue inline... > Signed-off-by: Oscar Salvador > --- > mm/memory_hotplug.c | 61 +++++++++++++++++++++++++++++------------------------ > 1 file changed, 34 insertions(+), 27 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 7deb49f69e27..29a5fc89bdb1 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1034,8 +1034,10 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) > return pgdat; > } > > -static void rollback_node_hotadd(int nid, pg_data_t *pgdat) > +static void rollback_node_hotadd(int nid) > { > + pg_data_t *pgdat = NODE_DATA(nid); > + > arch_refresh_nodedata(nid, NULL); > free_percpu(pgdat->per_cpu_nodestats); > arch_free_nodedata(pgdat); > @@ -1046,28 +1048,43 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat) > /** > * try_online_node - online a node if offlined > * @nid: the node ID > - * > + * @start: start addr of the node > + * @set_node_online: Whether we want to online the node > * called by cpu_up() to online a node without onlined memory. > */ > -int try_online_node(int nid) > +static int __try_online_node(int nid, u64 start, bool set_node_online) > { > - pg_data_t *pgdat; > - int ret; > + pg_data_t *pgdat; > + int ret = 1; > > if (node_online(nid)) > return 0; > > - mem_hotplug_begin(); > - pgdat = hotadd_new_pgdat(nid, 0); > + pgdat = hotadd_new_pgdat(nid, start); > if (!pgdat) { > pr_err("Cannot online node %d due to NULL pgdat\n", nid); > ret = -ENOMEM; > goto out; > } > - node_set_online(nid); > - ret = register_one_node(nid); > - BUG_ON(ret); > + > + if (set_node_online) { > + node_set_online(nid); > + ret = register_one_node(nid); > + BUG_ON(ret); > + } > out: > + return ret; > +} > + > +/* > + * Users of this function always want to online/register the node > + */ > +int try_online_node(int nid) > +{ > + int ret; > + > + mem_hotplug_begin(); > + ret = __try_online_node (nid, 0, true); > mem_hotplug_done(); > return ret; > } > @@ -1099,8 +1116,6 @@ static int online_memory_block(struct memory_block *mem, void *arg) > int __ref add_memory_resource(int nid, struct resource *res, bool online) > { > u64 start, size; > - pg_data_t *pgdat = NULL; > - bool new_pgdat; > bool new_node; > int ret; > > @@ -1111,11 +1126,6 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > if (ret) > return ret; > > - { /* Stupid hack to suppress address-never-null warning */ > - void *p = NODE_DATA(nid); > - new_pgdat = !p; > - } > - > mem_hotplug_begin(); > > /* > @@ -1126,17 +1136,14 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > */ > memblock_add_node(start, size, nid); > > - new_node = !node_online(nid); > - if (new_node) { > - pgdat = hotadd_new_pgdat(nid, start); > - ret = -ENOMEM; > - if (!pgdat) > - goto error; > - } > + ret = __try_online_node (nid, start, false); space before ( > + new_node = !!(ret > 0); > + if (ret < 0) > + goto error; > + > > /* call arch's memory hotadd */ > ret = arch_add_memory(nid, start, size, NULL, true); > - > if (ret < 0) > goto error; > > @@ -1180,8 +1187,8 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > > error: > /* rollback pgdat allocation and others */ > - if (new_pgdat && pgdat) > - rollback_node_hotadd(nid, pgdat); > + if (new_node) > + rollback_node_hotadd(nid); > memblock_remove(start, size); > > out: