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Date: Wed, 29 Mar 2017 14:55:33 +0800
From: Peter Xu <peterx@redhat.com>
Message-ID: <20170329065533.GD3152@pxdev.xzpeter.org>
References: <20170323204544.12015-1-quintela@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 05/51] ram: Move bitmap_sync_count into
 RAMState
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To: Juan Quintela <quintela@redhat.com>
Cc: qemu-devel@nongnu.org, dgilbert@redhat.com

On Tue, Mar 28, 2017 at 12:56:06PM +0200, Juan Quintela wrote:
> Peter Xu <peterx@redhat.com> wrote:
> > On Thu, Mar 23, 2017 at 09:44:58PM +0100, Juan Quintela wrote:
> >> Signed-off-by: Juan Quintela <quintela@redhat.com>
> >> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >
> > Reviewed-by: Peter Xu <peterx@redhat.com>
> >
> > (I see that we have MigrationStats.dirty_pages_rate which looks
> >  similar to this one. Maybe one day we can merge these two?)
> 
> no, this one is how many times we have synchronized the dirty bitmap
> with kvm/rest of qemu.
> dirty_pages_rame is the pages we have dirtied in some <period>.
> 
> Period is not clear, it tries to be around one second, but that part is
> not specially well done.

Oh, sorry... I was trying to mean MigrationStats.dirty_sync_count, not
MigrationStats.dirty_pages_rate. I think it was introduced in:

    commit 58570ed894631904bcdbcd1e8b34479cebe2aae9
    Author: ChenLiang <chenliang88@huawei.com>
    Date:   Fri Apr 4 17:57:55 2014 +0800

    migration: expose the bitmap_sync_count to the end

And these two variables are synchronized every time in
migration_bitmap_sync(), so looks the same. Thanks,

-- peterx