[v1] Background snapshots

[Qemu-devel] [PATCH v1 05/17] ram: extend the data structures for background snapshotting

Posted by Denis Plotnikov 7 years, 6 months ago

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
---
 include/exec/ram_addr.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 6cbc02aa0f..5b403d537d 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -36,6 +36,8 @@ struct RAMBlock {
     char idstr[256];
     /* RCU-enabled, writes protected by the ramlist lock */
     QLIST_ENTRY(RAMBlock) next;
+    /* blocks used for background snapshot */
+    QLIST_ENTRY(RAMBlock) bgs_next;
     QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
     int fd;
     size_t page_size;
@@ -49,6 +51,11 @@ struct RAMBlock {
     unsigned long *unsentmap;
     /* bitmap of already received pages in postcopy */
     unsigned long *receivedmap;
+    /* The following 2 are for background snapshot */
+    /* Pages currently being copied */
+    unsigned long *touched_map;
+    /* Pages has been copied already */
+    unsigned long *copied_map;
 };
 
 static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
-- 
2.17.0

Re: [Qemu-devel] [PATCH v1 05/17] ram: extend the data structures for background snapshotting

Posted by Peter Xu 7 years, 6 months ago

On Wed, Jul 18, 2018 at 06:41:48PM +0300, Denis Plotnikov wrote:
> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
> ---
>  include/exec/ram_addr.h | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> index 6cbc02aa0f..5b403d537d 100644
> --- a/include/exec/ram_addr.h
> +++ b/include/exec/ram_addr.h
> @@ -36,6 +36,8 @@ struct RAMBlock {
>      char idstr[256];
>      /* RCU-enabled, writes protected by the ramlist lock */
>      QLIST_ENTRY(RAMBlock) next;
> +    /* blocks used for background snapshot */
> +    QLIST_ENTRY(RAMBlock) bgs_next;
>      QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
>      int fd;
>      size_t page_size;
> @@ -49,6 +51,11 @@ struct RAMBlock {
>      unsigned long *unsentmap;
>      /* bitmap of already received pages in postcopy */
>      unsigned long *receivedmap;
> +    /* The following 2 are for background snapshot */
> +    /* Pages currently being copied */
> +    unsigned long *touched_map;
> +    /* Pages has been copied already */
> +    unsigned long *copied_map;
>  };
>  
>  static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
> -- 
> 2.17.0
> 
> 

IMHO these new fields can be put into the patches where they are
firstly used.  Isolating them do not really help much for anything
AFAICT...

Regards,

-- 
Peter Xu