From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58091) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WW907-0005vr-GG for qemu-devel@nongnu.org; Fri, 04 Apr 2014 14:38:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WW903-0000bo-4b for qemu-devel@nongnu.org; Fri, 04 Apr 2014 14:38:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40896) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WW902-0000bi-Sc for qemu-devel@nongnu.org; Fri, 04 Apr 2014 14:37:59 -0400 Date: Fri, 4 Apr 2014 18:40:35 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20140404174035.GD6393@work-vm> References: <1396605482-8720-1-git-send-email-arei.gonglei@huawei.com> <533EEAE1.3040005@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <533EEAE1.3040005@redhat.com> Subject: Re: [Qemu-devel] For 2.0? Re: [PATCH v5 00/10] migration: Optimizate the xbzrle and fix one corruption issue List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: ChenLiang , weidong.huang@huawei.com, quintela@redhat.com, qemu-devel@nongnu.org, arei.gonglei@huawei.com, pbonzini@redhat.com * Eric Blake (eblake@redhat.com) wrote: > On 04/04/2014 03:57 AM, arei.gonglei@huawei.com wrote: > > From: ChenLiang > > > > 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 / dgilbert@redhat.com / Manchester, UK