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

[Gonglei (Arei)]

Hi,

Ping, what's the patch sets status? Thanks.



Best regards,
-Gonglei


> -----Original Message-----
> From: Dr. David Alan Gilbert [mailto:address@hidden
> Sent: Saturday, April 05, 2014 1:41 AM
> To: Eric Blake
> Cc: Gonglei (Arei); address@hidden; address@hidden;
> address@hidden; Huangweidong (C); chenliang (T)
> Subject: Re: For 2.0? Re: [PATCH v5 00/10] migration: Optimizate the xbzrle 
> and
> fix one corruption issue
> 
> * Eric Blake (address@hidden) wrote:
> > 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?
> 
> The first one (Fix one XBZRLE corruption issue) is probably worth it;
> however my understanding is that it can only cause this corruption
> in the case where the source qemu runs out of RAM, and a few months
> ago that used to be the case where the source qemu would abort at that
> point, so it wasn't pleasent then.
> 
> Everything is else is an improvement.
> 
> Dave
> 
> > >
> > >
> > > 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
> >
> 
> 
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK