[Qemu-devel] For 2.0? Re: [PATCH v5 00/10] migration: Optimizate the xbzrle and fix one corruption issue

[Eric Blake]

On 04/04/2014 03:57 AM, address@hidden wrote:
> From: ChenLiang <address@hidden>
> 
> V5-->V4
> * Fix two issues: one is cache_insert don't update the page which
>   has been in the cache. Another avoiding the risk that run
>   xbzrle_encode_buffer on changing data.

Is all or part of this series essential to have in 2.0 to avoid having a
regression?

> 
> 
> a. Optimization the xbzrle remarkable decrease the cache misses.
>     The efficiency of compress increases more than fifty times.
>     Before the patch set, the cache almost totally miss when the
>     number of cache item less than the dirty page number. Now the
>     hot pages in the cache will not be replaced by other pages.
> 
> b. Reducing the data copy
> 
> c. Fix one corruption issues.
> 
> ChenLiang (10):
>   XBZRLE: Fix one XBZRLE corruption issues

Based on name, this patch is worth including in the release, if it is
not too late.

>   migration: Add counts of updating the dirty bitmap
>   migration: expose the bitmap_sync_count to the end user
>   migration: expose xbzrle cache miss rate

whereas these names sound like new features, and thus should wait for 2.1.

>   XBZRLE: optimize XBZRLE to decrease the cache misses
>   XBZRLE: rebuild the cache_is_cached function
>   xbzrle: don't check the value in the vm ram repeatedly
>   xbzrle: check 8 bytes at a time after an concurrency scene
>   migration: optimize xbzrle by reducing data copy
>   migration: clear the dead code
> 
>  arch_init.c                    |  74 +++++++++++++++++-------------
>  docs/xbzrle.txt                |   8 ++++
>  hmp.c                          |   4 ++
>  include/migration/migration.h  |   2 +
>  include/migration/page_cache.h |  10 ++--
>  migration.c                    |   3 ++
>  page_cache.c                   | 101 
> +++++++++++------------------------------
>  qapi-schema.json               |   9 +++-
>  qmp-commands.hx                |  15 ++++--
>  xbzrle.c                       |  48 ++++++++++++++------
>  10 files changed, 144 insertions(+), 130 deletions(-)
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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