search for: migration_bitmap_sync

...page logging before getting > > the free pages informant from guest. Even some of the free pages are modified by the guest > > during the process of getting the free pages information, these modified pages will be traced > > by the dirty page logging mechanism. So in the following migration_bitmap_sync() function. > > The pages in the free pages bitmap, but latter was modified, will be reset to dirty. We won't > > omit any dirtied pages. > > > > So, guest doesn't need to keep any free pages. > > OK, yes, that works; so we do: > * enable dirty logging &...

...page logging before getting > > the free pages informant from guest. Even some of the free pages are modified by the guest > > during the process of getting the free pages information, these modified pages will be traced > > by the dirty page logging mechanism. So in the following migration_bitmap_sync() function. > > The pages in the free pages bitmap, but latter was modified, will be reset to dirty. We won't > > omit any dirtied pages. > > > > So, guest doesn't need to keep any free pages. > > OK, yes, that works; so we do: > * enable dirty logging &...

...e free pages informant from guest. > > > > Even some of the free pages are modified by the guest during the > > > > process of getting the free pages information, these modified pages will > > be traced by the dirty page logging mechanism. So in the following > > migration_bitmap_sync() function. > > > > The pages in the free pages bitmap, but latter was modified, will be > > > > reset to dirty. We won't omit any dirtied pages. > > > > > > > > So, guest doesn't need to keep any free pages. > > > > > > OK,...

...e free pages informant from guest. > > > > Even some of the free pages are modified by the guest during the > > > > process of getting the free pages information, these modified pages will > > be traced by the dirty page logging mechanism. So in the following > > migration_bitmap_sync() function. > > > > The pages in the free pages bitmap, but latter was modified, will be > > > > reset to dirty. We won't omit any dirtied pages. > > > > > > > > So, guest doesn't need to keep any free pages. > > > > > > OK,...

...olve this, starting the dirty page logging before getting the free pages informant from guest. Even some of the free pages are modified by the guest during the process of getting the free pages information, these modified pages will be traced by the dirty page logging mechanism. So in the following migration_bitmap_sync() function. The pages in the free pages bitmap, but latter was modified, will be reset to dirty. We won't omit any dirtied pages. So, guest doesn't need to keep any free pages. > 2) Clearing out caches > Does it make sense to clean caches? They're apparently useful data...

...olve this, starting the dirty page logging before getting the free pages informant from guest. Even some of the free pages are modified by the guest during the process of getting the free pages information, these modified pages will be traced by the dirty page logging mechanism. So in the following migration_bitmap_sync() function. The pages in the free pages bitmap, but latter was modified, will be reset to dirty. We won't omit any dirtied pages. So, guest doesn't need to keep any free pages. > 2) Clearing out caches > Does it make sense to clean caches? They're apparently useful data...

...'t like hardcoding to a specific method. What about the reverse approach: Code may register a handler that populates the free_pages_bitmap which is called during this stage? <I like the idea of filtering in general, but I haven't looked at the code yet> > + } > + > migration_bitmap_sync(); > qemu_mutex_unlock_ramlist(); > qemu_mutex_unlock_iothread();

...ng before getting the free pages informant from guest. > > > Even some of the free pages are modified by the guest during the > > > process of getting the free pages information, these modified pages will > be traced by the dirty page logging mechanism. So in the following > migration_bitmap_sync() function. > > > The pages in the free pages bitmap, but latter was modified, will be > > > reset to dirty. We won't omit any dirtied pages. > > > > > > So, guest doesn't need to keep any free pages. > > > > OK, yes, that works; so we do: &gt...

...n_get_free_pages(migration_bitmap_rcu->free_pages_bmap, + &free_pages_count) == 0) { + usleep(1000); + } + qemu_mutex_lock_iothread(); + + filter_out_guest_free_pages(migration_bitmap_rcu->free_pages_bmap); + } + migration_bitmap_sync(); qemu_mutex_unlock_ramlist(); qemu_mutex_unlock_iothread(); -- 1.8.3.1

...ting the dirty page logging before getting > the free pages informant from guest. Even some of the free pages are modified by the guest > during the process of getting the free pages information, these modified pages will be traced > by the dirty page logging mechanism. So in the following migration_bitmap_sync() function. > The pages in the free pages bitmap, but latter was modified, will be reset to dirty. We won't > omit any dirtied pages. > > So, guest doesn't need to keep any free pages. OK, yes, that works; so we do: * enable dirty logging * ask guest for free pages * ini...

The current QEMU live migration implementation mark the all the guest's RAM pages as dirtied in the ram bulk stage, all these pages will be processed and that takes quit a lot of CPU cycles. >From guest's point of view, it doesn't care about the content in free pages. We can make use of this fact and skip processing the free pages in the ram bulk stage, it can save a lot CPU cycles

The current QEMU live migration implementation mark the all the guest's RAM pages as dirtied in the ram bulk stage, all these pages will be processed and that takes quit a lot of CPU cycles. >From guest's point of view, it doesn't care about the content in free pages. We can make use of this fact and skip processing the free pages in the ram bulk stage, it can save a lot CPU cycles

> > Could provide more information on how to use virtio-serial to exchange > data? Thread , Wiki or code are all OK. > > I have not find some useful information yet. > > See this commit in the Linux sources: > > 108fc82596e3b66b819df9d28c1ebbc9ab5de14c > > that adds a way to send guest trace data over to the host. I think that's the > most relevant to

> > Could provide more information on how to use virtio-serial to exchange > data? Thread , Wiki or code are all OK. > > I have not find some useful information yet. > > See this commit in the Linux sources: > > 108fc82596e3b66b819df9d28c1ebbc9ab5de14c > > that adds a way to send guest trace data over to the host. I think that's the > most relevant to