Re: [PATCH v1 12/29] virtio-mem: factor out fake-offlining into virtio_mem_fake_offline()

From: Pankaj Gupta
Date: Tue Oct 20 2020 - 05:31:36 EST


> ... which now matches virtio_mem_fake_online(). We'll reuse this
> functionality soon.
>
> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
> Cc: Jason Wang <jasowang@xxxxxxxxxx>
> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
> drivers/virtio/virtio_mem.c | 34 ++++++++++++++++++++++++----------
> 1 file changed, 24 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
> index 00d1cfca4713..d132bc54ef57 100644
> --- a/drivers/virtio/virtio_mem.c
> +++ b/drivers/virtio/virtio_mem.c
> @@ -832,6 +832,27 @@ static void virtio_mem_fake_online(unsigned long pfn, unsigned long nr_pages)
> }
> }
>
> +/*
> + * Try to allocate a range, marking pages fake-offline, effectively
> + * fake-offlining them.
> + */
> +static int virtio_mem_fake_offline(unsigned long pfn, unsigned long nr_pages)
> +{
> + int rc;
> +
> + rc = alloc_contig_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE,
> + GFP_KERNEL);
> + if (rc == -ENOMEM)
> + /* whoops, out of memory */
> + return rc;
> + if (rc)
> + return -EBUSY;
> +
> + virtio_mem_set_fake_offline(pfn, nr_pages, true);
> + adjust_managed_page_count(pfn_to_page(pfn), -nr_pages);
> + return 0;
> +}
> +
> static void virtio_mem_online_page_cb(struct page *page, unsigned int order)
> {
> const unsigned long addr = page_to_phys(page);
> @@ -1335,17 +1356,10 @@ static int virtio_mem_mb_unplug_sb_online(struct virtio_mem *vm,
>
> start_pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
> sb_id * vm->subblock_size);
> - rc = alloc_contig_range(start_pfn, start_pfn + nr_pages,
> - MIGRATE_MOVABLE, GFP_KERNEL);
> - if (rc == -ENOMEM)
> - /* whoops, out of memory */
> - return rc;
> - if (rc)
> - return -EBUSY;
>
> - /* Mark it as fake-offline before unplugging it */
> - virtio_mem_set_fake_offline(start_pfn, nr_pages, true);
> - adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
> + rc = virtio_mem_fake_offline(start_pfn, nr_pages);
> + if (rc)
> + return rc;
>
> /* Try to unplug the allocated memory */
> rc = virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, count);

Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>