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Re: [Qemu-devel] [PATCH v3 3/3] migration: add bitmap for received page
From: |
Juan Quintela |
Subject: |
Re: [Qemu-devel] [PATCH v3 3/3] migration: add bitmap for received page |
Date: |
Wed, 21 Jun 2017 21:22:07 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) |
Alexey Perevalov <address@hidden> wrote:
> This patch adds ability to track down already received
> pages, it's necessary for calculation vCPU block time in
> postcopy migration feature, maybe for restore after
> postcopy migration failure.
> Also it's necessary to solve shared memory issue in
> postcopy livemigration. Information about received pages
> will be transferred to the software virtual bridge
> (e.g. OVS-VSWITCHD), to avoid fallocate (unmap) for
> already received pages. fallocate syscall is required for
> remmaped shared memory, due to remmaping itself blocks
> ioctl(UFFDIO_COPY, ioctl in this case will end with EEXIT
> error (struct page is exists after remmap).
>
> Bitmap is placed into RAMBlock as another postcopy/precopy
> related bitmaps.
>
> Signed-off-by: Alexey Perevalov <address@hidden>
Hi
A few commets.
Happy with all the changes that you did.
> @@ -60,6 +62,7 @@ static inline void *ramblock_ptr(RAMBlock *block,
> ram_addr_t offset)
> return (char *)block->host + offset;
> }
>
> +unsigned long int ramblock_recv_bitmap_offset(void *host_addr, RAMBlock *rb);
> long qemu_getrampagesize(void);
> unsigned long last_ram_page(void);
> RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
I think we shouldn't export it at all. But if we do, we should export
it with the other functions.
> +unsigned long int ramblock_recv_bitmap_offset(void *host_addr, RAMBlock *rb)
I think this function can be made static, as nothing else should use it, no?
> +{
> + uint64_t host_addr_offset = (uint64_t)(uintptr_t)(host_addr
> + - (void *)rb->host);
Intdentation is weird:
uint64_t host_addr_offset =
(uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
> + return host_addr_offset >> TARGET_PAGE_BITS;
> +}
> +
> +int ramblock_recv_bitmap_test(void *host_addr, RAMBlock *rb)
> +{
> + return test_bit(ramblock_recv_bitmap_offset(host_addr, rb),
> + rb->receivedmap);
> +}
> +
> +void ramblock_recv_bitmap_set(void *host_addr, RAMBlock *rb)
> +{
> + set_bit_atomic(ramblock_recv_bitmap_offset(host_addr, rb),
> rb->receivedmap);
Line is too long?
> +static void ramblock_recv_bitmap_clear_range(uint64_t start, size_t length,
> + RAMBlock *rb)
> +{
> + int i, range_count;
> + range_count = length >> TARGET_PAGE_BITS;
> + for (i = 0; i < range_count; i++) {
> + ramblock_recv_bitmap_clear((void *)((uint64_t)(intptr_t)rb->host +
> + start), rb);
> + start += TARGET_PAGE_SIZE;
bitmap_clear(dst, pos, nbits) Clear specified bit area
Looks like the right operation here, no?
> +
> +void ramblock_recv_map_init(void);
> +int ramblock_recv_bitmap_test(void *host_addr, RAMBlock *rb);
> +void ramblock_recv_bitmap_set(void *host_addr, RAMBlock *rb);
> +void ramblock_recv_bitmap_clear(void *host_addr, RAMBlock *rb);
> +
> #endif
Later, Juan.
- [Qemu-devel] [PATCH v3 0/3] Add bitmap for received pages in postcopy migration, Alexey Perevalov, 2017/06/16
- Message not available
- Message not available
- [Qemu-devel] [PATCH v3 3/3] migration: add bitmap for received page, Alexey Perevalov, 2017/06/16
- Re: [Qemu-devel] [PATCH v3 3/3] migration: add bitmap for received page, Dr. David Alan Gilbert, 2017/06/23
- Re: [Qemu-devel] [PATCH v3 3/3] migration: add bitmap for received page, Perevalov Alexey, 2017/06/23
- Re: [Qemu-devel] [PATCH v3 3/3] migration: add bitmap for received page, Dr. David Alan Gilbert, 2017/06/23
- Re: [Qemu-devel] [PATCH v3 3/3] migration: add bitmap for received page, Perevalov Alexey, 2017/06/24
Message not available