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Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the share
From: |
Juan Quintela |
Subject: |
Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory |
Date: |
Wed, 10 Aug 2016 11:11:17 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) |
"Li, Liang Z" <address@hidden> wrote:
>> On Wed, Aug 10, 2016 at 10:22 AM, Li, Liang Z <address@hidden> wrote:
>> > Hi Jiangshan,
>> >
>> > Glad to see your patch. It's a simple implementation which could provide
>> very useful functions.
>> >
>> >> +static void migration_bitmap_init(unsigned long *bitmap) {
>> >> + RAMBlock *block;
>> >> +
>> >> + bitmap_clear(bitmap, 0, last_ram_offset() >> TARGET_PAGE_BITS);
>> >> + rcu_read_lock();
>> >> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
>> >> + if (!migrate_bypass_shared_memory()
>> >> || !qemu_ram_is_shared(block)) {
>> >> + bitmap_set(bitmap, block->offset >> TARGET_PAGE_BITS,
>> >
>> > You should use (block->offset >> TARGET_PAGE_BITS )/ BITS_PER_LONG
>> here.
>>
>> Hello, Li
>>
>> I might have missed something, could you tell me more?
>>
>> void bitmap_set(unsigned long *map, long start, long nr); I think the @start
>> and @nr are both the number of the bits.
>>
>> thanks,
>> Lai
>
> You are right, I have make a mistake by checking the code. Sorry for the
> noise.
>
> BTW. Is it possible to bypass the shared block in the
> 'ram_find_and_save_block'?
> I mean no to check if a page is dirty for a shared block, it may make things
> faster.
Nice spotted. That would make things faster. But once there we could
split the bitmap by ramblock, and the migration_dirty_pages also per
block, that would make all the searchs faster, and adding/removing
blocks of ram much easier. If we enter optimizing that function, we
could really do much better that the "again" parameter that we have
right now.
Later, Juan.
- [Qemu-devel] [PATCH] add migration capability to bypass the shared memory, Lai Jiangshan, 2016/08/09
- Re: [Qemu-devel] [PATCH] add migration capability to bypass the shared memory, no-reply, 2016/08/09
- Re: [Qemu-devel] [PATCH] add migration capability to bypass the shared memory, Dr. David Alan Gilbert, 2016/08/09
- [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Lai Jiangshan, 2016/08/09
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Fam Zheng, 2016/08/09
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Li, Liang Z, 2016/08/09
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Lai Jiangshan, 2016/08/09
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Li, Liang Z, 2016/08/10
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory,
Juan Quintela <=
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Li, Liang Z, 2016/08/11
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Lai Jiangshan, 2016/08/11
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Lai Jiangshan, 2016/08/11
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Li, Liang Z, 2016/08/12
- Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory, Lai Jiangshan, 2016/08/12
Re: [Qemu-devel] [PATCH] add migration capability to bypass the shared memory, Lai Jiangshan, 2016/08/09
Re: [Qemu-devel] [PATCH] add migration capability to bypass the shared memory, Juan Quintela, 2016/08/10