From: David Hildenbrand <david@redhat.com>
To: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Vlastimil Babka <vbabka@suse.cz>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 1/5] mm,memory_hotplug: Allocate memmap from the added memory range
Date: Thu, 25 Mar 2021 17:55:37 +0100 [thread overview]
Message-ID: <17e666ec-93ae-c0f3-47cf-67e8a6df6afc@redhat.com> (raw)
In-Reply-To: <YFy+olsdS4iwrovN@dhcp22.suse.cz>
On 25.03.21 17:47, Michal Hocko wrote:
> On Thu 25-03-21 17:36:22, Michal Hocko wrote:
>> If all it takes is to make pfn_to_online_page work (and my
>> previous attempt is incorrect because it should consult block rather
>> than section pfn range)
>
> This should work.
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 9697acfe96eb..e50d685be8ab 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -510,6 +510,23 @@ static struct memory_block *find_memory_block_by_id(unsigned long block_id)
> return mem;
> }
>
> +struct page *is_vmemmap_page(unsigned long pfn)
> +{
> + unsigned long nr = pfn_to_section_nr(pfn);
> + struct memory_block *mem;
> + unsigned long block_pfn;
> +
> + mem = find_memory_block_by_id(memory_block_id(nr));
> + if (!mem || !mem->nr_vmemmap_pages)
> + return NULL;
> +
> + block_pfn = section_nr_to_pfn(mem->start_section_nr);
> + if (pfn - block_pfn > mem->nr_vmemmap_pages)
> + return NULL;
> +
> + return pfn_to_page(pfn);
> +}
> +
> /*
> * Called under device_hotplug_lock.
> */
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 754026a9164d..760bf3ad48d5 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -304,8 +304,16 @@ struct page *pfn_to_online_page(unsigned long pfn)
> return NULL;
>
> ms = __nr_to_section(nr);
> - if (!online_section(ms))
> + if (!online_section(ms)) {
> + /*
> + * vmemmap reserved space can eat up a whole section which then
> + * never gets onlined because it doesn't contain any memory to
> + * online.
> + */
> + if (memmap_on_memory)
> + return is_vmemmap_page(pfn);
> return NULL;
> + }
>
> /*
> * Save some code text when online_section() +
>
It should take care of discussed zone shrinking as well, at least as
long as the granularity is not smaller than sub-sections.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-03-25 16:56 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 9:26 [PATCH v5 0/5] Allocate memmap from hotadded memory (per device) Oscar Salvador
2021-03-19 9:26 ` [PATCH v5 1/5] mm,memory_hotplug: Allocate memmap from the added memory range Oscar Salvador
2021-03-19 10:20 ` David Hildenbrand
2021-03-19 10:31 ` Oscar Salvador
2021-03-19 12:04 ` David Hildenbrand
2021-03-23 10:11 ` Michal Hocko
2021-03-24 10:12 ` Oscar Salvador
2021-03-24 12:03 ` Michal Hocko
2021-03-24 12:10 ` Michal Hocko
2021-03-24 12:23 ` David Hildenbrand
2021-03-24 12:37 ` Michal Hocko
2021-03-24 13:13 ` David Hildenbrand
2021-03-24 13:40 ` Michal Hocko
2021-03-24 14:05 ` David Hildenbrand
2021-03-24 13:27 ` Oscar Salvador
2021-03-24 14:42 ` Michal Hocko
2021-03-24 14:52 ` David Hildenbrand
2021-03-24 16:04 ` Michal Hocko
2021-03-24 19:16 ` David Hildenbrand
2021-03-25 8:07 ` Oscar Salvador
2021-03-25 9:17 ` Michal Hocko
2021-03-25 10:55 ` Oscar Salvador
2021-03-25 11:08 ` David Hildenbrand
2021-03-25 11:23 ` Oscar Salvador
2021-03-25 12:35 ` Michal Hocko
2021-03-25 12:40 ` David Hildenbrand
2021-03-25 14:08 ` Michal Hocko
2021-03-25 14:09 ` David Hildenbrand
2021-03-25 14:34 ` Michal Hocko
2021-03-25 14:46 ` David Hildenbrand
2021-03-25 15:12 ` Michal Hocko
2021-03-25 15:19 ` David Hildenbrand
2021-03-25 15:35 ` Michal Hocko
2021-03-25 15:40 ` David Hildenbrand
2021-03-25 16:07 ` Michal Hocko
2021-03-25 16:20 ` David Hildenbrand
2021-03-25 16:36 ` Michal Hocko
2021-03-25 16:47 ` Michal Hocko
2021-03-25 16:55 ` David Hildenbrand [this message]
2021-03-25 22:06 ` Oscar Salvador
2021-03-26 8:35 ` Michal Hocko
2021-03-26 8:52 ` David Hildenbrand
2021-03-26 8:57 ` Oscar Salvador
2021-03-26 12:15 ` Oscar Salvador
2021-03-26 13:36 ` David Hildenbrand
2021-03-26 14:38 ` Michal Hocko
2021-03-26 14:53 ` David Hildenbrand
2021-03-26 15:31 ` Michal Hocko
2021-03-26 16:03 ` David Hildenbrand
2021-03-26 8:55 ` Oscar Salvador
2021-03-26 9:11 ` Michal Hocko
2021-03-25 18:08 ` David Hildenbrand
2021-03-25 12:26 ` Michal Hocko
2021-03-25 14:02 ` Oscar Salvador
2021-03-25 14:40 ` Michal Hocko
2021-03-19 9:26 ` [PATCH v5 2/5] acpi,memhotplug: Enable MHP_MEMMAP_ON_MEMORY when supported Oscar Salvador
2021-03-23 10:40 ` Michal Hocko
2021-03-19 9:26 ` [PATCH v5 3/5] mm,memory_hotplug: Add kernel boot option to enable memmap_on_memory Oscar Salvador
2021-03-23 10:47 ` Michal Hocko
2021-03-24 8:45 ` Oscar Salvador
2021-03-24 9:02 ` Michal Hocko
2021-03-19 9:26 ` [PATCH v5 4/5] x86/Kconfig: Introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE Oscar Salvador
2021-03-19 9:26 ` [PATCH v5 5/5] arm64/Kconfig: " Oscar Salvador
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