From: David Hildenbrand <david@redhat.com>
To: Oscar Salvador <osalvador@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@kernel.org>,
VlastimilBabkavbabka@suse.cz, pasha.tatashin@soleen.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Anshuman Khandual <anshuman.khandual@arm.com>
Subject: Re: [PATCH v2 1/7] mm,memory_hotplug: Allocate memmap from the added memory range
Date: Mon, 1 Mar 2021 09:30:17 +0100 [thread overview]
Message-ID: <d02e77cf-fd23-2ccd-612e-b857a8140a1c@redhat.com> (raw)
In-Reply-To: <20210228185044.GA3929@localhost.localdomain>
>>> + (*online_page_callback)(pfn_to_page(pfn), pageblock_order);
>>> + pfn += 1 << pageblock_order;
>>
>> pfn += pageblock_nr_pages;
>>
>> Can you add a comment why we can be sure that we are off by a single pageblock? What about s390x where a MAX_ORDER_NR_PAGES == 4 * pageblock_nr_pages?
>>
>> Would it make thing simpler to just do a
>>
>> while (!IS_ALIGNED(pfn, MAX_ORDER_NR_PAGES)) {
>> (*online_page_callback)(pfn_to_page(pfn), 0);
>> pfn++;
>> }
>
> Honestly, I did not spend much time thinking on other platforms other
> than arm64/x86_64.
> But I think that that would be the universal solution as we do not make
> any assumptions.
>
> I will replace it.
I think you could also go with
while (!IS_ALIGNED(pfn, MAX_ORDER_NR_PAGES)) {
(*online_page_callback)(pfn_to_page(pfn), pageblock_order);
pageblock_nr_pages;
}
And maybe add a comment why we can be sure it has to be aligned to
pageblocks. Or maybe rather add
VM_BUG_ON(IS_ALIGNED(pfn, pageblock_nr_pages));
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-03-01 8:32 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 13:38 [PATCH v2 0/7] Allocate memmap from hotadded memory (per device) Oscar Salvador
2021-02-09 13:38 ` [PATCH v2 1/7] mm,memory_hotplug: Allocate memmap from the added memory range Oscar Salvador
2021-02-25 18:58 ` David Hildenbrand
2021-02-28 18:50 ` Oscar Salvador
2021-03-01 8:30 ` David Hildenbrand [this message]
2021-03-01 8:32 ` David Hildenbrand
2021-02-09 13:38 ` [PATCH v2 2/7] acpi,memhotplug: Enable MHP_MEMMAP_ON_MEMORY when supported Oscar Salvador
2021-02-09 13:38 ` [PATCH v2 3/7] mm,memory_hotplug: Add kernel boot option to enable memmap_on_memory Oscar Salvador
2021-02-25 18:25 ` David Hildenbrand
2021-02-26 12:14 ` Oscar Salvador
2021-03-01 8:27 ` David Hildenbrand
2021-02-09 13:38 ` [PATCH v2 4/7] mm,memory_hotplug: Enforce struct page size to be multiple of PMD Oscar Salvador
2021-02-25 18:26 ` David Hildenbrand
2021-02-26 12:06 ` Oscar Salvador
2021-03-01 10:06 ` Oscar Salvador
2021-03-01 10:24 ` David Hildenbrand
2021-02-09 13:38 ` [PATCH v2 5/7] mm,memory_hotplug: Enforce pageblock alignment when memmap_on_memory Oscar Salvador
2021-02-25 18:27 ` David Hildenbrand
2021-02-26 12:06 ` Oscar Salvador
2021-02-09 13:38 ` [PATCH v2 6/7] x86/Kconfig: Introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE Oscar Salvador
2021-02-25 18:29 ` David Hildenbrand
2021-02-26 12:04 ` Oscar Salvador
2021-03-01 8:45 ` David Hildenbrand
2021-03-01 10:07 ` Oscar Salvador
2021-02-09 13:38 ` [PATCH v2 7/7] arm64/Kconfig: " Oscar Salvador
2021-02-25 18:29 ` David Hildenbrand
2021-02-26 12:10 ` Oscar Salvador
2021-02-17 10:18 ` [PATCH v2 0/7] Allocate memmap from hotadded memory (per device) Oscar Salvador
2021-02-22 11:15 ` Oscar Salvador
2021-02-22 11:28 ` David Hildenbrand
2021-02-23 7:48 ` Oscar Salvador
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