[v2] migration: Make multifd not experimental

[Qemu-devel] [PATCH v2 6/8] multifd: Change default packet size

Posted by Juan Quintela 6 years, 8 months ago

We moved from 64KB to 512KB, as it makes less locking contention
without any downside in testing.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index 75a8fc21f8..d57db00ce4 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -521,7 +521,7 @@ exit:
 #define MULTIFD_FLAG_SYNC (1 << 0)
 
 /* This value needs to be a multiple of qemu_target_page_size() */
-#define MULTIFD_PACKET_SIZE (64 * 1024)
+#define MULTIFD_PACKET_SIZE (512 * 1024)
 
 typedef struct {
     uint32_t magic;
-- 
2.20.1

Re: [Qemu-devel] [PATCH v2 6/8] multifd: Change default packet size

Posted by Dr. David Alan Gilbert 6 years, 8 months ago

* Juan Quintela (quintela@redhat.com) wrote:
> We moved from 64KB to 512KB, as it makes less locking contention
> without any downside in testing.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>

That arbitrary number seems better than the previous arbitrary number,
so:

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/ram.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 75a8fc21f8..d57db00ce4 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -521,7 +521,7 @@ exit:
>  #define MULTIFD_FLAG_SYNC (1 << 0)
>  
>  /* This value needs to be a multiple of qemu_target_page_size() */
> -#define MULTIFD_PACKET_SIZE (64 * 1024)
> +#define MULTIFD_PACKET_SIZE (512 * 1024)
>  
>  typedef struct {
>      uint32_t magic;
> -- 
> 2.20.1
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK