On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote: > On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote: > > On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote: > > > > > > > > > > > > > > > + if (!arrays) > > > > > + return NULL; > > > > > + > > > > > + for (i = 0; i < max_array_num; i++) { > > > > So we are getting a ton of memory here just to free it up a bit later. > > > > Why doesn't get_from_free_page_list get the pages from free list for us? > > > > We could also avoid the 1st allocation then - just build a list > > > > of these. > > > That wouldn't be a good choice for us. If we check how the regular > > > allocation works, there are many many things we need to consider when pages > > > are allocated to users. > > > For example, we need to take care of the nr_free > > > counter, we need to check the watermark and perform the related actions. > > > Also the folks working on arch_alloc_page to monitor page allocation > > > activities would get a surprise..if page allocation is allowed to work in > > > this way. > > > > > mm/ code is well positioned to handle all this correctly. > > I'm afraid that would be a re-implementation of the alloc functions, A re-factoring - you can share code. The main difference is locking. > and > that would be much more complex than what we have. I think your idea of > passing a list of pages is better. > > Best, > Wei How much memory is this allocating anyway? -- MST