From: Oscar Salvador <osalvador@suse.de>
To: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@kernel.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 v4 1/5] mm,memory_hotplug: Allocate memmap from the added memory range
Date: Thu, 18 Mar 2021 09:27:48 +0100 [thread overview]
Message-ID: <YFMPBFSJPq2VEOk9@localhost.localdomain> (raw)
In-Reply-To: <f996f570-eed9-509f-553c-280a62dc6d20@redhat.com>
On Wed, Mar 17, 2021 at 03:35:41PM +0100, David Hildenbrand wrote:
> Just assume you have two ranges
>
> [ ZONE_DEVICE 0 ][ ZONE_DEVICE 1]
>
> If the vmemmap of ZONE_DEVICE 1 could be taken from the altmap of
> ZONE_DEVICE 0, we could be in trouble, as both parts can be
> removed/repurposed independently ...
I have to say my knowledge about ZONE_DEVICE and its intrinsencs tend to
0, that is why I thought it might not matter, but I agree that this is
only asking for trouble.
> If we check for
>
> IS_ALIGNED(nr_vmemmap_pages, PMD_SIZE), please add a proper TODO comment
> that this is most probably the wrong place to take care of this.
Sure, I will stuff the check in there and place a big TODO comment so we
do not forget about addressing this issue the right way.
I will prepare a v5 (hopefully the last one) and do some more testing
before sending it out.
Thanks David!
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2021-03-18 8:28 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-09 17:55 [PATCH v4 0/5] Allocate memmap from hotadded memory (per device) Oscar Salvador
2021-03-09 17:55 ` [PATCH v4 1/5] mm,memory_hotplug: Allocate memmap from the added memory range Oscar Salvador
2021-03-11 19:06 ` David Hildenbrand
2021-03-15 10:22 ` Oscar Salvador
2021-03-16 16:46 ` David Hildenbrand
2021-03-16 17:45 ` David Hildenbrand
2021-03-17 14:08 ` Oscar Salvador
2021-03-17 14:35 ` David Hildenbrand
2021-03-18 8:27 ` Oscar Salvador [this message]
2021-03-18 10:38 ` Oscar Salvador
2021-03-18 11:24 ` David Hildenbrand
2021-03-18 12:03 ` Oscar Salvador
2021-03-18 12:05 ` David Hildenbrand
2021-03-09 17:55 ` [PATCH v4 2/5] acpi,memhotplug: Enable MHP_MEMMAP_ON_MEMORY when supported Oscar Salvador
2021-03-09 17:55 ` [PATCH v4 3/5] mm,memory_hotplug: Add kernel boot option to enable memmap_on_memory Oscar Salvador
2021-03-09 17:55 ` [PATCH v4 4/5] x86/Kconfig: Introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE Oscar Salvador
2021-03-09 17:55 ` [PATCH v4 5/5] arm64/Kconfig: " Oscar Salvador
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