Google
  Web www.spinics.net

Re: qemu-kvm.git now live

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


Jan Kiszka wrote:
If migration disables dirty memory logging, it must keep the vga logging
enabled, and vice versa.

So we need some notifier callbacks on slot changes so that all users can
re-enable dirty logging after the update as required.

Simpler to do reference counting. When a user enables logging for a memory range, the refcount for all slots containing that range gets bumped. When a user enables logging for all of memory, a global refcount is bumped. For a given slot, dirty logging is enabled if either the slot logging refcount or the global logging refcount is nonzero.

That's sort of what's implemented in qemu-kvm.git. In qemu.git vga logging does not get disabled, which is really broken. It prevents optimizations like disabling logging when the screen is not displayed to a human.

Where/how does the
migration code disable dirty logging?

Should be phase 3 of ram_save_live().

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

--
To unsubscribe from this list: send the line "unsubscribe kvm-ia64" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Home]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Photo]     [Yosemite News]    [Yosemite Photos]    [Video Projectors]     [PDAs]     [Free Online Dating]     [Hacking TiVo]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Devices]     [Big List of Linux Books]     [16.7MP]

  Powered by Linux