Displaying 2 results from an estimated 2 matches for "virtio_fs_setup_dax".
2020 Nov 09
3
[PATCH v3 3/6] mm: support THP migration to device private memory
On Fri, Nov 06, 2020 at 01:26:50PM -0800, Ralph Campbell wrote:
>
> On 11/6/20 12:03 AM, Christoph Hellwig wrote:
>> I hate the extra pin count magic here. IMHO we really need to finish
>> off the series to get rid of the extra references on the ZONE_DEVICE
>> pages first.
>
> First, thanks for the review comments.
>
> I don't like the extra refcount
2020 Nov 11
0
[PATCH v3 3/6] mm: support THP migration to device private memory
..._device_private_page() and adjusting the expected reference count when the
page isn't mapped by any process. There is a clear allocation and free so it
can be changed to use a reference count of zero while free (see [2]).
MEMORY_DEVICE_FS_DAX:
Struct pages are created in pmem_attach_disk() and virtio_fs_setup_dax() with
an initial reference count of one.
The problem I see is that there are 3 states that are important:
a) memory is free and not allocated to any file (page_ref_count() == 0).
b) memory is allocated to a file and in the page cache (page_ref_count() == 1).
c) some gup() or I/O has a reference ev...