On Wed, Sep 06, Andrew Cooper wrote: > I still fail to understand why you need the bitmaps at all? You can > calculate everything you need from the pfn list alone, which will also > let you spot the presence or absence of the VGA hole.
These bitmaps track if a range has been allocated as superpage or not. If there is a given pfn within a range of either 1G or 2M there might be double allocation of a 1G or 2M page. This is not related to the VGA hole. These two lines are just hints that in this range no superpage can be allocated. > You need to track which pfns you've see so far in the stream, and which > pfns have been populated. When you find holes in the pfns in the > stream, you need to undo the prospective superpage allocation. Unless > I've missed something? This is whats happening, holes will be created as soon as they are seen in the stream. > Also, please take care to use 2M decrease reservations wherever > possible, or you will end up shattering the host superpage as part of > trying to remove the memory. This is what Wei suggested, build a list of pfns instead of releasing each pfn individually. I think with this new code it should be possible to decrease in 2M steps as needed. Olaf
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