[CRIU] Re: [RFC] [PATCH cr 0/16] Restore copy-on-write regions (v2)

Pavel Emelyanov xemul at parallels.com
Tue Oct 30 12:41:38 EDT 2012


On 10/23/2012 02:02 PM, Andrey Vagin wrote:
> This series is based on two facts.
> * Copy-on-write regions can be in MAP_PRIVATE mappings
> * pages-[PID].img is a content of MAP_PRIVATE mappings
> 
> So we can restore all private mappings before forking children and
> all copy-on-write regions will be restored automatically.
> 
> Here is only one problem, that a mapping can not be restored in a
> correct place, because it may be conflict with crtools' mappings.
> The mapping get avaliable address and then remmaped in restorer.
> 
> v2: * Remove unshared pages from inherited mappings.
>     * Avoid conflict of premmapped vma-s and target vma-s
> .
> 


Overall comment -- I'd like to see some stats in restore logs saying
how much pages were not-restored with cow optimization.

Thanks,
Pavel


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