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[62.201.165.239]) by smtp.gmail.com with ESMTPSA id y17-v6sm23774170wrh.49.2018.09.21.06.26.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 21 Sep 2018 06:26:42 -0700 (PDT) Received: from d104.suse.de (nat.nue.novell.com [195.135.221.2]) by techadventures.net (Postfix) with ESMTPA id C655E12533E; Fri, 21 Sep 2018 15:26:40 +0200 (CEST) From: Oscar Salvador To: akpm@linux-foundation.org Cc: mhocko@suse.com, dan.j.williams@intel.com, david@redhat.com, Pavel.Tatashin@microsoft.com, Jonathan.Cameron@huawei.com, yasu.isimatu@gmail.com, malat@debian.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador Subject: [PATCH v2 3/4] mm/memory_hotplug: Simplify node_states_check_changes_online Date: Fri, 21 Sep 2018 15:26:33 +0200 Message-Id: <20180921132634.10103-4-osalvador@techadventures.net> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180921132634.10103-1-osalvador@techadventures.net> References: <20180921132634.10103-1-osalvador@techadventures.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oscar Salvador While looking at node_states_check_changes_online, I stumbled upon some confusing things. Right after entering the function, we find this: if (N_MEMORY == N_NORMAL_MEMORY) zone_last = ZONE_MOVABLE; This is wrong. N_MEMORY cannot really be equal to N_NORMAL_MEMORY. My guess is that this wanted to be something like: if (N_NORMAL_MEMORY == N_HIGH_MEMORY) to check if we have CONFIG_HIGHMEM. Later on, in the CONFIG_HIGHMEM block, we have: if (N_MEMORY == N_HIGH_MEMORY) zone_last = ZONE_MOVABLE; Again, this is wrong, and will never be evaluated to true. Besides removing these wrong if statements, I simplified the function a bit. Signed-off-by: Oscar Salvador Suggested-by: Pavel Tatashin --- mm/memory_hotplug.c | 57 +++++++---------------------------------------------- 1 file changed, 7 insertions(+), 50 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 561c44761f95..eadd149eb7bc 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -687,62 +687,19 @@ static void node_states_check_changes_online(unsigned long nr_pages, struct zone *zone, struct memory_notify *arg) { int nid = zone_to_nid(zone); - enum zone_type zone_last = ZONE_NORMAL; - /* - * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] - * contains nodes which have zones of 0...ZONE_NORMAL, - * set zone_last to ZONE_NORMAL. - * - * If we don't have HIGHMEM nor movable node, - * node_states[N_NORMAL_MEMORY] contains nodes which have zones of - * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. - */ - if (N_MEMORY == N_NORMAL_MEMORY) - zone_last = ZONE_MOVABLE; + arg->status_change_nid = -1; + arg->status_change_nid_normal = -1; + arg->status_change_nid_high = -1; - /* - * if the memory to be online is in a zone of 0...zone_last, and - * the zones of 0...zone_last don't have memory before online, we will - * need to set the node to node_states[N_NORMAL_MEMORY] after - * the memory is online. - */ - if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY)) + if (!node_state(nid, N_MEMORY)) + arg->status_change_nid = nid; + if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) arg->status_change_nid_normal = nid; - else - arg->status_change_nid_normal = -1; - #ifdef CONFIG_HIGHMEM - /* - * If we have movable node, node_states[N_HIGH_MEMORY] - * contains nodes which have zones of 0...ZONE_HIGHMEM, - * set zone_last to ZONE_HIGHMEM. - * - * If we don't have movable node, node_states[N_NORMAL_MEMORY] - * contains nodes which have zones of 0...ZONE_MOVABLE, - * set zone_last to ZONE_MOVABLE. - */ - zone_last = ZONE_HIGHMEM; - if (N_MEMORY == N_HIGH_MEMORY) - zone_last = ZONE_MOVABLE; - - if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY)) + if (zone_idx(zone) <= N_HIGH_MEMORY && !node_state(nid, N_HIGH_MEMORY)) arg->status_change_nid_high = nid; - else - arg->status_change_nid_high = -1; -#else - arg->status_change_nid_high = arg->status_change_nid_normal; #endif - - /* - * if the node don't have memory befor online, we will need to - * set the node to node_states[N_MEMORY] after the memory - * is online. - */ - if (!node_state(nid, N_MEMORY)) - arg->status_change_nid = nid; - else - arg->status_change_nid = -1; } static void node_states_set_node(int node, struct memory_notify *arg) -- 2.13.6