Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v6 3/8] mm,memory_hotplug: Factor out adjusting present
 pages into adjust_present_page_count()
To:     Oscar Salvador <osalvador@suse.de>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Michal Hocko <mhocko@kernel.org>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Pavel Tatashin <pasha.tatashin@soleen.com>,
        Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20210406111115.8953-1-osalvador@suse.de>
 <20210406111115.8953-4-osalvador@suse.de>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat GmbH
Message-ID: <f2682c45-1a7d-cefa-ccf1-af54898421f1@redhat.com>
Date:   Tue, 6 Apr 2021 17:33:46 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.1
MIME-Version: 1.0
In-Reply-To: <20210406111115.8953-4-osalvador@suse.de>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 06.04.21 13:11, Oscar Salvador wrote:
> From: David Hildenbrand <david@redhat.com>
> 
> Let's have a single place (inspired by adjust_managed_page_count()) where
> we adjust present pages, to prepare for additional bookkeeping.

Maybe in the context of this series, remove the "additional bookkeeping" 
part.

> In contrast to adjust_managed_page_count(), only memory onlining/offlining
> is allowed to modify the number of present pages.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
> Reviewed-by: Oscar Salvador <osalvador@suse.de>
> ---
>   mm/memory_hotplug.c | 22 ++++++++++++----------
>   1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 5fe3e3942b19..7411f6b5287d 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -829,6 +829,16 @@ struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
>   	return default_zone_for_pfn(nid, start_pfn, nr_pages);
>   }
>   
> +static void adjust_present_page_count(struct zone *zone, long nr_pages)
> +{
> +	unsigned long flags;
> +
> +	zone->present_pages += nr_pages;
> +	pgdat_resize_lock(zone->zone_pgdat, &flags);
> +	zone->zone_pgdat->node_present_pages += nr_pages;
> +	pgdat_resize_unlock(zone->zone_pgdat, &flags);
> +}
> +
>   int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
>   		       int online_type, int nid)
>   {
> @@ -881,11 +891,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
>   	}
>   
>   	online_pages_range(pfn, nr_pages);
> -	zone->present_pages += nr_pages;
> -
> -	pgdat_resize_lock(zone->zone_pgdat, &flags);
> -	zone->zone_pgdat->node_present_pages += nr_pages;
> -	pgdat_resize_unlock(zone->zone_pgdat, &flags);
> +	adjust_present_page_count(zone, nr_pages);
>   
>   	node_states_set_node(nid, &arg);
>   	if (need_zonelists_rebuild)
> @@ -1699,11 +1705,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
>   
>   	/* removal success */
>   	adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
> -	zone->present_pages -= nr_pages;
> -
> -	pgdat_resize_lock(zone->zone_pgdat, &flags);
> -	zone->zone_pgdat->node_present_pages -= nr_pages;
> -	pgdat_resize_unlock(zone->zone_pgdat, &flags);
> +	adjust_present_page_count(zone, -nr_pages);
>   
>   	init_per_zone_wmark_min();
>   
> 


-- 
Thanks,

David / dhildenb