From: Balbir Singh <bsingharora@gmail.com>
To: "Jérôme Glisse" <jglisse@redhat.com>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Cc: John Hubbard <jhubbard@nvidia.com>,
Dan Williams <dan.j.williams@intel.com>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
David Nellans <dnellans@nvidia.com>,
Evgeny Baskakov <ebaskakov@nvidia.com>,
Mark Hairgrove <mhairgrove@nvidia.com>,
Sherry Cheung <SCheung@nvidia.com>,
Subhash Gutti <sgutti@nvidia.com>
Subject: Re: [HMM 14/16] mm/hmm/devmem: device memory hotplug using ZONE_DEVICE
Date: Fri, 07 Apr 2017 11:37:34 +1000 [thread overview]
Message-ID: <1491529054.12351.16.camel@gmail.com> (raw)
In-Reply-To: <20170405204026.3940-15-jglisse@redhat.com>
On Wed, 2017-04-05 at 16:40 -0400, Jérôme Glisse wrote:
> This introduce a simple struct and associated helpers for device driver
> to use when hotpluging un-addressable device memory as ZONE_DEVICE. It
> will find a unuse physical address range and trigger memory hotplug for
> it which allocates and initialize struct page for the device memory.
>
> Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com>
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
> Signed-off-by: Sherry Cheung <SCheung@nvidia.com>
> Signed-off-by: Subhash Gutti <sgutti@nvidia.com>
> ---
> include/linux/hmm.h | 114 +++++++++++++++
> mm/Kconfig | 9 ++
> mm/hmm.c | 398 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 521 insertions(+)
>
> +/*
> + * To add (hotplug) device memory, HMM assumes that there is no real resource
> + * that reserves a range in the physical address space (this is intended to be
> + * use by unaddressable device memory). It will reserve a physical range big
> + * enough and allocate struct page for it.
I've found that the implementation of this is quite non-portable, in that
starting from iomem_resource.end+1-size (which is effectively -size) on
my platform (powerpc) does not give expected results. It could be that
additional changes are needed to arch_add_memory() to support this
use case.
> +
> + size = ALIGN(size, SECTION_SIZE);
> + addr = (iomem_resource.end + 1ULL) - size;
Why don't we allocate_resource() with the right constraints and get a new
unused region?
Thanks,
Balbir
next prev parent reply other threads:[~2017-04-07 1:38 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-05 20:40 [HMM 00/16] HMM (Heterogeneous Memory Management) v19 Jérôme Glisse
2017-04-05 20:40 ` [HMM 01/16] mm/memory/hotplug: add memory type parameter to arch_add/remove_memory Jérôme Glisse
2017-04-06 9:45 ` Anshuman Khandual
2017-04-06 13:58 ` Jerome Glisse
2017-04-07 12:13 ` Michal Hocko
2017-04-07 14:32 ` Jerome Glisse
2017-04-07 14:45 ` Michal Hocko
2017-04-07 14:57 ` Jerome Glisse
2017-04-07 15:11 ` Michal Hocko
2017-04-07 16:10 ` Jerome Glisse
2017-04-07 16:37 ` Michal Hocko
2017-04-07 17:10 ` Jerome Glisse
2017-04-07 17:59 ` Michal Hocko
2017-04-07 18:27 ` Jerome Glisse
2017-04-05 20:40 ` [HMM 02/16] mm/put_page: move ZONE_DEVICE page reference decrement v2 Jérôme Glisse
2017-04-05 20:40 ` [HMM 03/16] mm/unaddressable-memory: new type of ZONE_DEVICE for unaddressable memory Jérôme Glisse
2017-04-05 20:40 ` [HMM 04/16] mm/ZONE_DEVICE/x86: add support for un-addressable device memory Jérôme Glisse
2017-04-05 20:40 ` [HMM 05/16] mm/migrate: new migrate mode MIGRATE_SYNC_NO_COPY Jérôme Glisse
2017-04-05 20:40 ` [HMM 06/16] mm/migrate: new memory migration helper for use with device memory v4 Jérôme Glisse
2017-04-05 20:40 ` [HMM 07/16] mm/migrate: migrate_vma() unmap page from vma while collecting pages Jérôme Glisse
2017-04-05 20:40 ` [HMM 08/16] mm/hmm: heterogeneous memory management (HMM for short) Jérôme Glisse
2017-04-05 20:40 ` [HMM 09/16] mm/hmm/mirror: mirror process address space on device with HMM helpers Jérôme Glisse
2017-04-05 20:40 ` [HMM 10/16] mm/hmm/mirror: helper to snapshot CPU page table v2 Jérôme Glisse
2017-04-10 8:35 ` Michal Hocko
2017-04-10 8:43 ` Michal Hocko
2017-04-10 22:10 ` Andrew Morton
2017-04-11 1:33 ` Jerome Glisse
2017-04-11 20:33 ` Andrew Morton
2017-04-05 20:40 ` [HMM 11/16] mm/hmm/mirror: device page fault handler Jérôme Glisse
2017-04-05 20:40 ` [HMM 12/16] mm/migrate: support un-addressable ZONE_DEVICE page in migration Jérôme Glisse
2017-04-05 20:40 ` [HMM 13/16] mm/migrate: allow migrate_vma() to alloc new page on empty entry Jérôme Glisse
2017-04-05 20:40 ` [HMM 14/16] mm/hmm/devmem: device memory hotplug using ZONE_DEVICE Jérôme Glisse
2017-04-06 21:22 ` Jerome Glisse
2017-04-07 1:37 ` Balbir Singh [this message]
2017-04-07 2:02 ` Jerome Glisse
2017-04-07 16:26 ` Jerome Glisse
2017-04-10 4:31 ` Balbir Singh
2017-04-05 20:40 ` [HMM 15/16] mm/hmm/devmem: dummy HMM device for ZONE_DEVICE memory v2 Jérôme Glisse
2017-04-05 20:40 ` [HMM 16/16] hmm: heterogeneous memory management documentation Jérôme Glisse
[not found] ` <CAF7GXvptCfV89rAi=j1cy1df12039GDpq_DHOyx+_xk0FjBDPg@mail.gmail.com>
2017-04-06 4:59 ` [HMM 00/16] HMM (Heterogeneous Memory Management) v19 Jerome Glisse
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