On Wed, Jun 27, 2018 at 09:24:18AM +0800, Wei Wang wrote:
On 06/26/2018 09:34 PM, Michael S. Tsirkin wrote:Hmm I guess I'm missing something, I don't see it:
On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote:For every 2TB memory that the guest has, we allocate 4MB.
On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote:A re-factoring - you can share code. The main difference is locking.
On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote:I'm afraid that would be a re-implementation of the alloc functions,
mm/ code is well positioned to handle all this correctly.That wouldn't be a good choice for us. If we check how the regular+ if (!arrays)So we are getting a ton of memory here just to free it up a bit later.
+ return NULL;
+
+ for (i = 0; i < max_array_num; i++) {
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.
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.
andHow much memory is this allocating anyway?
that would be much more complex than what we have. I think your idea of
passing a list of pages is better.
Best,
Wei
+ max_entries = max_free_page_blocks(ARRAY_ALLOC_ORDER);
+ entries_per_page = PAGE_SIZE / sizeof(__le64);
+ entries_per_array = entries_per_page * (1 << ARRAY_ALLOC_ORDER);
+ max_array_num = max_entries / entries_per_array +
+ !!(max_entries % entries_per_array);
Looks like you always allocate the max number?