| Date | Fri, 16 Oct 2020 16:03:44 +0800 | From | Wei Yang <> | Subject | Re: [PATCH v1 15/29] virito-mem: document Sub Block Mode (SBM) |
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On Mon, Oct 12, 2020 at 02:53:09PM +0200, David Hildenbrand wrote: >Let's add some documentation for the current mode - Sub Block Mode (SBM) - >to prepare for a new mode - Big Block Mode (BBM). > >Follow-up patches will properly factor out the existing Sub Block Mode >(SBM) and implement Device Block Mode (DBM). > >Cc: "Michael S. Tsirkin" <mst@redhat.com> >Cc: Jason Wang <jasowang@redhat.com> >Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> >Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
>--- > drivers/virtio/virtio_mem.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > >diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c >index faeb759687fe..fd8685673fe4 100644 >--- a/drivers/virtio/virtio_mem.c >+++ b/drivers/virtio/virtio_mem.c >@@ -27,6 +27,21 @@ static bool unplug_online = true; > module_param(unplug_online, bool, 0644); > MODULE_PARM_DESC(unplug_online, "Try to unplug online memory"); > >+/* >+ * virtio-mem currently supports the following modes of operation: >+ * >+ * * Sub Block Mode (SBM): A Linux memory block spans 1..X subblocks (SB). The >+ * size of a Sub Block (SB) is determined based on the device block size, the >+ * pageblock size, and the maximum allocation granularity of the buddy. >+ * Subblocks within a Linux memory block might either be plugged or unplugged. >+ * Memory is added/removed to Linux MM in Linux memory block granularity. >+ * >+ * User space / core MM (auto onlining) is responsible for onlining added >+ * Linux memory blocks - and for selecting a zone. Linux Memory Blocks are >+ * always onlined separately, and all memory within a Linux memory block is >+ * onlined to the same zone - virtio-mem relies on this behavior. >+ */ >+ > enum virtio_mem_mb_state { > /* Unplugged, not added to Linux. Can be reused later. */ > VIRTIO_MEM_MB_STATE_UNUSED = 0, >-- >2.26.2
-- Wei Yang Help you, Help me
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