From: David Hildenbrand <david@redhat.com>
To: Oscar Salvador <osalvador@suse.de>, Michal Hocko <mhocko@kernel.org>
Cc: akpm@linux-foundation.org, dan.j.williams@intel.com,
Jonathan.Cameron@huawei.com, anshuman.khandual@arm.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 0/4] mm,memory_hotplug: allocate memmap from hotadded memory
Date: Wed, 3 Apr 2019 10:36:04 +0200 [thread overview]
Message-ID: <a2ebe8c0-916e-1117-acfd-0ac2300a7dfd@redhat.com> (raw)
In-Reply-To: <20190403083359.vqbzy5krjfzfjedx@d104.suse.de>
On 03.04.19 10:34, Oscar Salvador wrote:
> On Wed, Apr 03, 2019 at 10:12:32AM +0200, Michal Hocko wrote:
>> What does prevent calling somebody arch_add_memory for a range spanning
>> multiple memblocks from a driver directly. In other words aren't you
>> making assumptions about a future usage based on the qemu usecase?
>
> Well, right now they cannot as it is not exported.
> But if we want to do it in the future, then yes, I would have to
> be more careful because I made the assumption that hot-add/hot-remove
> are working with the same granularity, which is the case right now.
>
> Given said this, I think that something like you said before, giving
> the option to the caller to specify whether it wants vmemmaps per the
> whole hot-added range or per memblock is a reasonable thing to do.
> That way, there will not be a problem working with different granularities
> in hot-add/hot-remove operations and we would be on safe side.
There might still be an issue if the person adding memory might be
somebody else removing memory. I am not yet sure if we should even allow
add_memory/remove_memory with different granularity. But as I noted,
ACPI and powernv.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2019-04-03 8:36 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-28 13:43 [PATCH 0/4] mm,memory_hotplug: allocate memmap from hotadded memory Oscar Salvador
2019-03-28 13:43 ` [PATCH 1/4] mm, memory_hotplug: cleanup memory offline path Oscar Salvador
2019-04-03 8:43 ` Michal Hocko
2019-03-28 13:43 ` [PATCH 2/4] mm, memory_hotplug: provide a more generic restrictions for memory hotplug Oscar Salvador
2019-04-03 8:46 ` Michal Hocko
2019-04-03 8:48 ` David Hildenbrand
2019-04-04 10:04 ` Oscar Salvador
2019-04-04 10:06 ` David Hildenbrand
2019-04-04 10:31 ` Michal Hocko
2019-04-04 12:04 ` Oscar Salvador
2019-03-28 13:43 ` [PATCH 3/4] mm, memory_hotplug: allocate memmap from the added memory range for sparse-vmemmap Oscar Salvador
2019-03-28 13:43 ` [PATCH 4/4] mm, sparse: rename kmalloc_section_memmap, __kfree_section_memmap Oscar Salvador
2019-03-28 15:09 ` [PATCH 0/4] mm,memory_hotplug: allocate memmap from hotadded memory David Hildenbrand
2019-03-28 15:31 ` David Hildenbrand
2019-03-29 8:45 ` Oscar Salvador
2019-03-29 8:56 ` David Hildenbrand
2019-03-29 9:01 ` David Hildenbrand
2019-03-29 9:20 ` Oscar Salvador
2019-03-29 13:42 ` Michal Hocko
2019-04-01 7:59 ` Oscar Salvador
2019-04-01 11:53 ` Michal Hocko
2019-04-02 8:28 ` Oscar Salvador
2019-04-02 8:39 ` David Hildenbrand
2019-04-02 12:48 ` Michal Hocko
2019-04-03 8:01 ` Oscar Salvador
2019-04-03 8:12 ` Michal Hocko
2019-04-03 8:17 ` David Hildenbrand
2019-04-03 8:37 ` Michal Hocko
2019-04-03 8:41 ` David Hildenbrand
2019-04-03 8:49 ` Michal Hocko
2019-04-03 8:53 ` David Hildenbrand
2019-04-03 8:50 ` Oscar Salvador
2019-04-03 8:54 ` David Hildenbrand
2019-04-03 9:40 ` Oscar Salvador
2019-04-03 10:46 ` Michal Hocko
2019-04-04 10:25 ` Vlastimil Babka
2019-04-03 8:34 ` Oscar Salvador
2019-04-03 8:36 ` David Hildenbrand [this message]
2019-03-29 8:30 ` Oscar Salvador
2019-03-29 8:51 ` David Hildenbrand
2019-03-29 22:23 ` John Hubbard
2019-04-01 7:52 ` Oscar Salvador
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