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Re: [Qemu-devel] [PATCH v9 3/5] mm: function to offer a page block on th
From: |
Andrew Morton |
Subject: |
Re: [Qemu-devel] [PATCH v9 3/5] mm: function to offer a page block on the free list |
Date: |
Thu, 13 Apr 2017 13:02:17 -0700 |
On Thu, 13 Apr 2017 17:35:06 +0800 Wei Wang <address@hidden> wrote:
> Add a function to find a page block on the free list specified by the
> caller. Pages from the page block may be used immediately after the
> function returns. The caller is responsible for detecting or preventing
> the use of such pages.
>
> ...
>
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -4498,6 +4498,93 @@ void show_free_areas(unsigned int filter)
> show_swap_cache_info();
> }
>
> +/**
> + * Heuristically get a page block in the system that is unused.
> + * It is possible that pages from the page block are used immediately after
> + * inquire_unused_page_block() returns. It is the caller's responsibility
> + * to either detect or prevent the use of such pages.
> + *
> + * The free list to check: zone->free_area[order].free_list[migratetype].
> + *
> + * If the caller supplied page block (i.e. **page) is on the free list, offer
> + * the next page block on the list to the caller. Otherwise, offer the first
> + * page block on the list.
> + *
> + * Return 0 when a page block is found on the caller specified free list.
> + */
> +int inquire_unused_page_block(struct zone *zone, unsigned int order,
> + unsigned int migratetype, struct page **page)
> +{
Perhaps we can wrap this in the appropriate ifdef so the kernels which
won't be using virtio-balloon don't carry the added overhead.
- [Qemu-devel] [PATCH v9 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Wei Wang, 2017/04/13
- [Qemu-devel] [PATCH v9 1/5] virtio-balloon: deflate via a page list, Wei Wang, 2017/04/13
- [Qemu-devel] [PATCH v9 2/5] virtio-balloon: VIRTIO_BALLOON_F_BALLOON_CHUNKS, Wei Wang, 2017/04/13
- [Qemu-devel] [PATCH v9 4/5] mm: export symbol of next_zone and first_online_pgdat, Wei Wang, 2017/04/13
- [Qemu-devel] [PATCH v9 5/5] virtio-balloon: VIRTIO_BALLOON_F_MISC_VQ, Wei Wang, 2017/04/13
- [Qemu-devel] [PATCH v9 3/5] mm: function to offer a page block on the free list, Wei Wang, 2017/04/13
- Re: [Qemu-devel] [PATCH v9 3/5] mm: function to offer a page block on the free list,
Andrew Morton <=
Re: [Qemu-devel] [PATCH v9 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Matthew Wilcox, 2017/04/13