Re: [PATCH v1 29/29] virtio-mem: Big Block Mode (BBM) - safe memory hotunplug

From: Wei Yang
Date: Mon Oct 19 2020 - 20:25:00 EST


On Mon, Oct 12, 2020 at 02:53:23PM +0200, David Hildenbrand wrote:
>Let's add a safe mechanism to unplug memory, avoiding long/endless loops
>when trying to offline memory - similar to in SBM.
>
>Fake-offline all memory (via alloc_contig_range()) before trying to
>offline+remove it. Use this mode as default, but allow to enable the other
>mode explicitly (which could give better memory hotunplug guarantees in
>some environments).
>
>The "unsafe" mode can be enabled e.g., via virtio_mem.bbm_safe_unplug=0
>on the cmdline.
>
>Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
>Cc: Jason Wang <jasowang@xxxxxxxxxx>
>Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
>Cc: Michal Hocko <mhocko@xxxxxxxxxx>
>Cc: Oscar Salvador <osalvador@xxxxxxx>
>Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
>Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>

Reviewed-by: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>

--
Wei Yang
Help you, Help me