Messages in this thread | | | Date | Thu, 13 Apr 2017 19:07:57 +0800 | From | Wei Wang <> | Subject | Re: [PATCH kernel v8 3/4] mm: add inerface to offer info about unused pages |
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On 03/17/2017 05:28 AM, Andrew Morton wrote: > On Thu, 16 Mar 2017 15:08:46 +0800 Wei Wang <wei.w.wang@intel.com> wrote: > >> From: Liang Li <liang.z.li@intel.com> >> >> This patch adds a function to provides a snapshot of the present system >> unused pages. An important usage of this function is to provide the >> unsused pages to the Live migration thread, which skips the transfer of >> thoses unused pages. Newly used pages can be re-tracked by the dirty >> page logging mechanisms. > I don't think this will be useful for anything other than > virtio-balloon. I guess it would be better to keep this code in the > virtio-balloon driver if possible, even though that's rather a layering > violation :( What would have to be done to make that possible? Perhaps > we can put some *small* helpers into page_alloc.c to prevent things > from becoming too ugly. > > Thanks for the suggestion. Small helpers do look more elegant. The nice thing is that I also didn't see any performance loss. To make that possible, we need to enable for_each_polulated_zone() to be callable by a kernel module. Please have a check the v9 patches that I just posted out.
Best, Wei
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